4 mg IV/IM immediately before anesthesia or after procedure or 16 mg PO 1 hr before anesthesia; patients >80 kg may need additional 4 mg IV

Total body radiation therapy: 8 mg PO 1-2 hours before radiation therapy; administered each day

Single high-dose fraction therapy to abdomen: 8 mg PO 1-2 hr before radiation therapy; administer subsequent doses every 8 hr after first dose 1-2 days after completion of therapy

Daily fractions to abdomen: Administer 8 mg PO 1-2 hr before radiotherapy; administer subsequent doses every 8 hr after first dose each day radiotherapy is given

Renal impairment: Dose adjustment not necessary

Severe hepatic impairment (Child-Pugh score ≥10): Not to exceed 8 mg/day

8 mg divided q12hr or 8 mg q8-12hr PO for 7 days up to 5 months

Alternatively, 4-8 mg intermittent short-term IV dosing used in adults; single dose of 4 mg single dose used in pregnancy

8 mg divided q12hr or 8 mg q8-12hr PO for 14 days up to 5 months

Prophylaxis: 4-8 mg IV 20-30 min prior to spinal opioid therapy; may repeat dosing at 12, 24, 36, 48 hr after spinal opioid dosing

4-8 mg PO q12hr for up to 3 weeks

Alternatively, 12 mg IV daily for 4 days

10 mg IV q8hr PRN

Ondansetron inhalation powder: Prevention of chemotherapy-induced nausea and vomiting due to highly emetogenic chemotherapy in pediatric patients (aged birth through 16 yr)

apomorphine, ondansetron. Mechanism: unspecified interaction mechanism. Contraindicated. Profound hypotension and loss of consciousness reported when 5HT3 antagonists are coadministered with apomorphine. Additionally, ondansetron may cause additive QT prolongation with apomorphine.

dronedarone will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. dronedarone and ondansetron both increase QTc interval. Contraindicated. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

lefamulin will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Lefamulin is contraindicated with CYP3A substrates know to prolong the QT interval.

posaconazole will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

abametapir will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. For 2 weeks after abametapir application, avoid taking drugs that are CYP3A4 substrates. If not feasible, avoid use of abametapir.

alfuzosin and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

ondansetron, almotriptan. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

amiodarone and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

amisulpride and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. ECG monitoring is recommended if coadministered.

amitriptyline and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias. ondansetron, amitriptyline. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

amoxapine and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias. ondansetron, amoxapine. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

apalutamide will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of apalutamide, a strong CYP3A4 inducer, with drugs that are CYP3A4 substrates can result in lower exposure to these medications. Avoid or substitute another drug for these medications when possible. Evaluate for loss of therapeutic effect if medication must be coadministered. Adjust dose according to prescribing information if needed.

arformoterol and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

aripiprazole and ondansetron both increase QTc interval. Avoid or Use Alternate Drug.

arsenic trioxide and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

artemether and ondansetron both increase QTc interval. Avoid or Use Alternate Drug.

artemether/lumefantrine and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

asenapine and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

atomoxetine and ondansetron both increase QTc interval. Avoid or Use Alternate Drug.

azithromycin and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

ceritinib and ondansetron both increase QTc interval. Avoid or Use Alternate Drug.

chlorpromazine and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

ciprofloxacin and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

citalopram and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias. ondansetron, citalopram. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

clarithromycin and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias. Potential for increased ondansetron levels. clarithromycin will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

clomipramine and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias. ondansetron, clomipramine. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

clozapine and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

crizotinib and ondansetron both decrease QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

dasatinib and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

degarelix and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

desflurane and ondansetron both increase QTc interval. Avoid or Use Alternate Drug.

desipramine and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias. ondansetron, desipramine. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

ondansetron, desvenlafaxine. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

deutetrabenazine and ondansetron both increase QTc interval. Avoid or Use Alternate Drug.

disopyramide and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

dofetilide and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

dolasetron and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

donepezil and ondansetron both increase QTc interval. Avoid or Use Alternate Drug.

ondansetron, doxepin. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

droperidol and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

ondansetron, duloxetine. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

efavirenz and ondansetron both increase QTc interval. Avoid or Use Alternate Drug.

ondansetron, eletriptan. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

encorafenib and ondansetron both increase QTc interval. Avoid or Use Alternate Drug.

entrectinib and ondansetron both increase QTc interval. Avoid or Use Alternate Drug.

enzalutamide will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

erdafitinib will increase the level or effect of ondansetron by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

eribulin and ondansetron both increase QTc interval. Avoid or Use Alternate Drug.

erythromycin base and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

erythromycin ethylsuccinate and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

erythromycin lactobionate and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

erythromycin stearate and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

escitalopram and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias. ondansetron, escitalopram. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

ezogabine and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

fexinidazole and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid coadministration of fexinidazole with drugs known to block potassium channels or prolong QT interval. fexinidazole will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Fexinidazole inhibits CYP3A4. Coadministration may increase risk for adverse effects of CYP3A4 substrates.

fingolimod and ondansetron both increase QTc interval. Avoid or Use Alternate Drug.

flecainide and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

fluconazole and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias. Combination may increase ondansetron levels.

fluoxetine and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias. ondansetron, fluoxetine. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

fluphenazine and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

fluvoxamine and ondansetron both increase serotonin levels. Avoid or Use Alternate Drug.

formoterol and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

foscarnet and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

ondansetron, frovatriptan. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

gemifloxacin and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

gilteritinib and ondansetron both increase QTc interval. Avoid or Use Alternate Drug.

ondansetron and glasdegib both increase QTc interval. Avoid or Use Alternate Drug. If coadministration unavoidable, monitor for increased risk of QTc interval prolongation.

granisetron and ondansetron both increase QTc interval. Avoid or Use Alternate Drug.

haloperidol and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

hydroxychloroquine sulfate and ondansetron both increase QTc interval. Avoid or Use Alternate Drug.

ibutilide and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

idelalisib will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Idelalisib is a strong CYP3A inhibitor; avoid coadministration with sensitive CYP3A substrates

iloperidone and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

ondansetron, imipramine. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

indacaterol, inhaled, ondansetron. QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

indapamide and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

inotuzumab and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. If unable to avoid concomitant use, obtain ECGs and electrolytes before and after initiation of any drug known to prolong QTc, and periodically monitor as clinically indicated during treatment.

ondansetron, isocarboxazid. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

isoflurane and ondansetron both increase QTc interval. Avoid or Use Alternate Drug.

isradipine and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

itraconazole and ondansetron both increase QTc interval. Avoid or Use Alternate Drug.

ivosidenib will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of sensitive CYP3A4 substrates with ivosidenib or replace with alternative therapies. If coadministration is unavoidable, monitor patients for loss of therapeutic effect of these drugs.

lapatinib and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias. Potential for increased ondansetron levels.

lasmiditan increases levels of ondansetron by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug.

levofloxacin and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

ondansetron, levomilnacipran. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

lithium and ondansetron both increase QTc interval. Avoid or Use Alternate Drug.

lopinavir will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

lumefantrine and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

macimorelin and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Macimorelin causes an increase of ~11 msec in the corrected QT interval. Avoid coadministration with drugs that prolong QT interval, which could increase risk for developing torsade de pointes-type ventricular tachycardia. Allow sufficient washout time of drugs that are known to prolong the QT interval before administering macimorelin.

maprotiline and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

mefloquine and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

methadone and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

mifepristone will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

ondansetron, milnacipran. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

mobocertinib and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. If coadministration unavoidable, reduce mobocertinib dose and monitor QTc interval more frequently.

moxifloxacin and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

ondansetron, naratriptan. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

nilotinib and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias. Potential for increased ondansetron levels.

nortriptyline and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias. ondansetron, nortriptyline. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

octreotide and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

ofloxacin and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

olanzapine and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

oxaliplatin and ondansetron both increase QTc interval. Avoid or Use Alternate Drug.

paliperidone and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

ondansetron, paroxetine. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

pazopanib and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

pentamidine and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

perphenazine and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

ondansetron, phenelzine. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

pimozide and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

ondansetron and pitolisant both increase QTc interval. Avoid or Use Alternate Drug.

posaconazole and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias. Potential for increased ondansetron levels.

primaquine and ondansetron both increase QTc interval. Avoid or Use Alternate Drug.

procainamide and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

propafenone and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

protriptyline and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias. ondansetron, protriptyline. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

quetiapine and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

quinidine and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

quinine and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

ranolazine and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

ondansetron, rasagiline. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

ribociclib and ondansetron both increase QTc interval. Avoid or Use Alternate Drug.

ondansetron and risperidone both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

ondansetron, rizatriptan. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

ondansetron and romidepsin both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

ondansetron and saquinavir both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias. saquinavir will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

ondansetron, selegiline. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

ondansetron, selegiline transdermal. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

ondansetron and sertraline both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias. ondansetron, sertraline. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

sevoflurane and ondansetron both increase QTc interval. Avoid or Use Alternate Drug.

ondansetron and solifenacin both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

ondansetron and sotalol both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

sotorasib will decrease the level or effect of ondansetron by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If use is unavoidable, refer to the prescribing information of the P-gp substrate for dosage modifications.

ondansetron, sumatriptan. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

ondansetron, sumatriptan intranasal. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

ondansetron and sunitinib both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

ondansetron and tacrolimus both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

tedizolid, ondansetron. Either increases effects of the other by Mechanism: pharmacodynamic synergism. Avoid or Use Alternate Drug. both increase serotonin levels; increased risk of serotonin syndrome.

ondansetron and telavancin both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

tepotinib will increase the level or effect of ondansetron by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If concomitant use unavoidable, reduce the P-gp substrate dosage if recommended in its approved product labeling.

thioridazine and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

ondansetron and thiothixene both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

ondansetron and toremifene both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

ondansetron, tranylcypromine. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

ondansetron and trimipramine both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias. ondansetron, trimipramine. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

tucatinib will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid concomitant use of tucatinib with CYP3A substrates, where minimal concentration changes may lead to serious or life-threatening toxicities. If unavoidable, reduce CYP3A substrate dose according to product labeling.

ondansetron increases toxicity of umeclidinium bromide/vilanterol inhaled by QTc interval. Avoid or Use Alternate Drug. Exercise extreme caution when vilanterol coadministered with drugs that prolong QTc interval; adrenergic agonist effects on the cardiovascular system may be potentiated.

vandetanib and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

ondansetron and vardenafil both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

ondansetron and vemurafenib both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias. Alterations in ondansetron concentrations may occur with concomitant use.

ondansetron, venlafaxine. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

ondansetron increases toxicity of vilanterol/fluticasone furoate inhaled by QTc interval. Avoid or Use Alternate Drug. Exercise extreme caution when vilanterol coadministered with drugs that prolong QTc interval; adrenergic agonist effects on the cardiovascular system may be potentiated.

ondansetron and voriconazole both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias. Potential for increased ondansetron levels. voriconazole will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

ondansetron and vorinostat both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

voxelotor will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Voxelotor increases systemic exposure of sensitive CYP3A4 substrates. Avoid coadministration with sensitive CYP3A4 substrates with a narrow therapeutic index. Consider dose reduction of the sensitive CYP3A4 substrate(s) if unable to avoid.

ziprasidone and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

ondansetron, zolmitriptan. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

albuterol and ondansetron both increase QTc interval. Use Caution/Monitor.

ondansetron and alfuzosin both increase QTc interval. Use Caution/Monitor.

amobarbital will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. No dosage adjustment for ondansetron is recommended for patients on these drugs.

atazanavir will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. CYP-450 inhibitors may decrease clearance of ondansetron. However, no dosage adjustment for ondansetron is recommended.

ondansetron and bedaquiline both increase QTc interval. Modify Therapy/Monitor Closely. ECG should be monitored closely

berotralstat will increase the level or effect of ondansetron by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Monitor or titrate P-gp substrate dose if coadministered.

bosutinib increases levels of ondansetron by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

butabarbital will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. No dosage adjustment for ondansetron is recommended for patients on these drugs.

carbamazepine will decrease the level or effect of ondansetron by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor. carbamazepine will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

cenobamate will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Increase dose of CYP3A4 substrate, as needed, when coadministered with cenobamate.

chloroquine increases toxicity of ondansetron by QTc interval. Use Caution/Monitor.

cobicistat will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

crizotinib increases levels of ondansetron by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

crofelemer increases levels of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Crofelemer has the potential to inhibit CYP3A4 at concentrations expected in the gut; unlikely to inhibit systemically because minimally absorbed.

dabrafenib will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely.

darunavir will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. CYP-450 inhibitors may decrease clearance of ondansetron. However, no dosage adjustment for ondansetron is recommended

deferasirox will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

dexamethasone will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. No dosage adjustment for ondansetron is recommended for patients on these drugs.

dichlorphenamide and ondansetron both decrease serum potassium. Use Caution/Monitor.

doxepin and ondansetron both increase QTc interval. Use Caution/Monitor.

efavirenz will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

elagolix will increase the level or effect of ondansetron by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. elagolix decreases levels of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Elagolix is a weak-to-moderate CYP3A4 inducer. Monitor CYP3A substrates if coadministered. Consider increasing CYP3A substrate dose if needed.

eliglustat increases levels of ondansetron by P-glycoprotein (MDR1) efflux transporter. Modify Therapy/Monitor Closely. Monitor therapeutic drug concentrations, as indicated, or consider reducing the dosage of the P-gp substrate and titrate to clinical effect.

elvitegravir/cobicistat/emtricitabine/tenofovir DF increases levels of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Cobicistat is a CYP3A4 inhibitor; contraindicated with CYP3A4 substrates for which elevated plasma concentrations are associated with serious and/or life-threatening events.

encorafenib, ondansetron. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Encorafenib both inhibits and induces CYP3A4 at clinically relevant plasma concentrations. Coadministration of encorafenib with sensitive CYP3A4 substrates may result in increased toxicity or decreased efficacy of these agents.

fedratinib will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

ondansetron decreases effects of fenfluramine by pharmacodynamic antagonism. Use Caution/Monitor. Potent serotonin receptor antagonists may decrease fenfluramine efficacy. If coadministered, monitor appropriately.

fosamprenavir will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. CYP-450 inhibitors may decrease clearance of ondansetron. However, no dosage adjustment for ondansetron is recommended

ondansetron and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.

gadobenate and ondansetron both increase QTc interval. Use Caution/Monitor.

ondansetron and gemtuzumab both increase QTc interval. Use Caution/Monitor.

glecaprevir/pibrentasvir will increase the level or effect of ondansetron by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

goserelin increases toxicity of ondansetron by QTc interval. Use Caution/Monitor. Increases risk of torsades de pointes.

histrelin increases toxicity of ondansetron by QTc interval. Use Caution/Monitor. Increases risk of torsades de pointes.

hydroxyzine increases toxicity of ondansetron by QTc interval. Use Caution/Monitor. Increases risk of torsades de pointes.

iloperidone increases levels of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Iloperidone is a time-dependent CYP3A inhibitor and may lead to increased plasma levels of drugs predominantly eliminated by CYP3A4.

indinavir will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. CYP-450 inhibitors may decrease clearance of ondansetron. However, no dosage adjustment for ondansetron is recommended

isoniazid will increase the level or effect of ondansetron by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor. CYP-450 inhibitors may decrease clearance of ondansetron. However, no dosage adjustment for ondansetron is recommended isoniazid will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. CYP-450 inhibitors may decrease clearance of ondansetron. However, no dosage adjustment for ondansetron is recommended

istradefylline will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Istradefylline 40 mg/day increased peak levels and AUC of CYP3A4 substrates in clinical trials. This effect was not observed with istradefylline 20 mg/day. Consider dose reduction of sensitive CYP3A4 substrates. istradefylline will increase the level or effect of ondansetron by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Istradefylline 40 mg/day increased peak levels and AUC of P-gp substrates in clinical trials. Consider dose reduction of sensitive P-gp substrates.

itraconazole will increase the level or effect of ondansetron by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. P-gp inhibitors may decrease clearance of ondansetron. No dosage adjustment for ondansetron is recommended

ivacaftor increases levels of ondansetron by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Ivacaftor and its M1 metabolite has the potential to inhibit P-gp; may significantly increase systemic exposure to sensitive P-gp substrates with a narrow therapeutic index.

ketoconazole will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. CYP-450 inhibitors may decrease clearance of ondansetron. However, no dosage adjustment for ondansetron is recommended

ondansetron and lenvatinib both increase QTc interval. Use Caution/Monitor. Lenvatinib prescribing information recommends monitoring ECG closely when coadministered with QT prolonging drugs.

letermovir increases levels of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

leuprolide increases toxicity of ondansetron by QTc interval. Use Caution/Monitor. Increases risk of torsades de pointes.

levoketoconazole will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. CYP-450 inhibitors may decrease clearance of ondansetron. However, no dosage adjustment for ondansetron is recommended

lomitapide increases levels of ondansetron by P-glycoprotein (MDR1) efflux transporter. Modify Therapy/Monitor Closely. Consider reducing dose when used concomitantly with lomitapide.

lonafarnib will increase the level or effect of ondansetron by P-glycoprotein (MDR1) efflux transporter. Modify Therapy/Monitor Closely. Lonafarnib is a weak P-gp inhibitor. Monitor for adverse reactions if coadministered with P-gp substrates where minimal concentration changes may lead to serious or life-threatening toxicities. Reduce P-gp substrate dose if needed.

lopinavir and ondansetron both increase QTc interval. Use Caution/Monitor. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

lorlatinib will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

ondansetron increases levels of metformin by Other (see comment). Use Caution/Monitor. Comment: Ondansetron inhibition of transporters (MATE or OCTs), which are responsible for active renal secretion of metformin may play a role.

mifepristone, ondansetron. QTc interval. Modify Therapy/Monitor Closely. Use alternatives if available.

mitotane decreases levels of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Mitotane is a strong inducer of cytochrome P-4503A4; monitor when coadministered with CYP3A4 substrates for possible dosage adjustments.

nefazodone will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. CYP-450 inhibitors may decrease clearance of ondansetron. However, no dosage adjustment for ondansetron is recommended

nelfinavir will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. CYP-450 inhibitors may decrease clearance of ondansetron. However, no dosage adjustment for ondansetron is recommended

osilodrostat and ondansetron both increase QTc interval. Use Caution/Monitor.

osimertinib and ondansetron both increase QTc interval. Use Caution/Monitor. Conduct periodic monitoring with ECGs and electrolytes in patients taking drugs known to prolong the QTc interval.

oxaliplatin will increase the level or effect of ondansetron by Other (see comment). Use Caution/Monitor. Monitor for ECG changes if therapy is initiated in patients with drugs known to prolong QT interval.

oxcarbazepine will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. No dosage adjustment for ondansetron is recommended for patients on these drugs.

ozanimod and ondansetron both increase QTc interval. Modify Therapy/Monitor Closely. The potential additive effects on heart rate, treatment with ozanimod should generally not be initiated in patients who are concurrently treated with QT prolonging drugs with known arrhythmogenic properties.

ondansetron and panobinostat both increase QTc interval. Modify Therapy/Monitor Closely. Panobinostat is known to significantly prolong QT interval. Panobinostat prescribing information states use with drugs known to prolong QTc is not recommended; however, antiemetic drugs known to prolong QTc (eg, dolasetron, granisetron, ondansetron) can be used with frequent ECG monitoring.

ondansetron and pasireotide both increase QTc interval. Modify Therapy/Monitor Closely.

pentobarbital will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. No dosage adjustment for ondansetron is recommended for patients on these drugs.

phenobarbital will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. No dosage adjustment for ondansetron is recommended for patients on these drugs.

phenytoin will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. No dosage adjustment for ondansetron is recommended for patients on these drugs.

ponatinib increases levels of ondansetron by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

ribociclib will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

rifabutin will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

rifampin will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

ritonavir and ondansetron both increase QTc interval. Use Caution/Monitor. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias. May increase ondansetron levels. ritonavir will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

rucaparib will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Adjust dosage of CYP3A4 substrates, if clinically indicated.

sarecycline will increase the level or effect of ondansetron by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Monitor for toxicities of P-gp substrates that may require dosage reduction when coadministered with P-gp inhibitors.

secobarbital will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. No dosage adjustment for ondansetron is recommended for patients on these drugs.

selpercatinib increases toxicity of ondansetron by QTc interval. Use Caution/Monitor.

sorafenib and ondansetron both increase QTc interval. Use Caution/Monitor.

St John's Wort will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

stiripentol, ondansetron. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Stiripentol is a CYP3A4 inhibitor and inducer. Monitor CYP3A4 substrates coadministered with stiripentol for increased or decreased effects. CYP3A4 substrates may require dosage adjustment. stiripentol will increase the level or effect of ondansetron by P-glycoprotein (MDR1) efflux transporter. Modify Therapy/Monitor Closely. Consider reducing the dose of P-glycoprotein (P-gp) substrates, if adverse reactions are experienced when administered concomitantly with stiripentol.

tazemetostat will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

tecovirimat will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Tecovirimat is a weak CYP3A4 inducer. Monitor sensitive CYP3A4 substrates for effectiveness if coadministered.

triclabendazole and ondansetron both increase QTc interval. Use Caution/Monitor.

triptorelin increases toxicity of ondansetron by QTc interval. Use Caution/Monitor. Increases risk of torsades de pointes.

tucatinib will increase the level or effect of ondansetron by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Consider reducing the dosage of P-gp substrates, where minimal concentration changes may lead to serious or life-threatening toxicities.

voclosporin, ondansetron. Either increases effects of the other by QTc interval. Use Caution/Monitor.

amobarbital will decrease the level or effect of ondansetron by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.

armodafinil will decrease the level or effect of ondansetron by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown. armodafinil will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

bosentan will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

butabarbital will decrease the level or effect of ondansetron by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.

cigarette smoking will decrease the level or effect of ondansetron by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.

conivaptan will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

diltiazem will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown. No dosage adjustment for ondansetron is recommended.

eslicarbazepine acetate will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown. No dosage adjustment for ondansetron is recommended for patients on these drugs.

etravirine will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

fosphenytoin will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

grapefruit will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

griseofulvin will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

mexiletine will increase the level or effect of ondansetron by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.

modafinil will decrease the level or effect of ondansetron by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.

nafcillin will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

nevirapine will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

peginterferon alfa 2a will increase the level or effect of ondansetron by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.

pentobarbital will decrease the level or effect of ondansetron by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.

phenobarbital will decrease the level or effect of ondansetron by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.

primidone will decrease the level or effect of ondansetron by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown. primidone will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

rifampin will decrease the level or effect of ondansetron by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.

rifapentine will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

topiramate will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

verapamil will increase the level or effect of ondansetron by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown. verapamil will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

zileuton will increase the level or effect of ondansetron by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown. No dosage adjustment is needed for ondansetron.

Serious - Use Alternative (1) abametapir will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. For 2 weeks after abametapir application, avoid taking drugs that are CYP3A4 substrates. If not feasible, avoid use of abametapir.

Monitor Closely (1) albuterol and ondansetron both increase QTc interval. Use Caution/Monitor.

Monitor Closely (1) ondansetron and alfuzosin both increase QTc interval. Use Caution/Monitor.Serious - Use Alternative (1) alfuzosin and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Serious - Use Alternative (1) ondansetron, almotriptan. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

Serious - Use Alternative (1) amiodarone and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Serious - Use Alternative (1) amisulpride and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. ECG monitoring is recommended if coadministered.

Serious - Use Alternative (2) amitriptyline and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias. ondansetron, amitriptyline. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

Monitor Closely (1) amobarbital will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. No dosage adjustment for ondansetron is recommended for patients on these drugs.Minor (1) amobarbital will decrease the level or effect of ondansetron by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.

Serious - Use Alternative (2) amoxapine and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias. ondansetron, amoxapine. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

Serious - Use Alternative (1) apalutamide will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of apalutamide, a strong CYP3A4 inducer, with drugs that are CYP3A4 substrates can result in lower exposure to these medications. Avoid or substitute another drug for these medications when possible. Evaluate for loss of therapeutic effect if medication must be coadministered. Adjust dose according to prescribing information if needed.

Contraindicated (1) apomorphine, ondansetron. Mechanism: unspecified interaction mechanism. Contraindicated. Profound hypotension and loss of consciousness reported when 5HT3 antagonists are coadministered with apomorphine. Additionally, ondansetron may cause additive QT prolongation with apomorphine.

Serious - Use Alternative (1) arformoterol and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Serious - Use Alternative (1) aripiprazole and ondansetron both increase QTc interval. Avoid or Use Alternate Drug.

Minor (2) armodafinil will decrease the level or effect of ondansetron by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown. armodafinil will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

Serious - Use Alternative (1) arsenic trioxide and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Serious - Use Alternative (1) artemether and ondansetron both increase QTc interval. Avoid or Use Alternate Drug.

Serious - Use Alternative (1) artemether/lumefantrine and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Serious - Use Alternative (1) asenapine and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Monitor Closely (1) atazanavir will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. CYP-450 inhibitors may decrease clearance of ondansetron. However, no dosage adjustment for ondansetron is recommended.

Serious - Use Alternative (1) atomoxetine and ondansetron both increase QTc interval. Avoid or Use Alternate Drug.

Serious - Use Alternative (1) azithromycin and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Monitor Closely (1) ondansetron and bedaquiline both increase QTc interval. Modify Therapy/Monitor Closely. ECG should be monitored closely

Monitor Closely (1) berotralstat will increase the level or effect of ondansetron by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Monitor or titrate P-gp substrate dose if coadministered.

Minor (1) bosentan will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

Monitor Closely (1) bosutinib increases levels of ondansetron by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

Monitor Closely (1) butabarbital will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. No dosage adjustment for ondansetron is recommended for patients on these drugs.Minor (1) butabarbital will decrease the level or effect of ondansetron by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.

Monitor Closely (2) carbamazepine will decrease the level or effect of ondansetron by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor. carbamazepine will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

Monitor Closely (1) cenobamate will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Increase dose of CYP3A4 substrate, as needed, when coadministered with cenobamate.

Serious - Use Alternative (1) ceritinib and ondansetron both increase QTc interval. Avoid or Use Alternate Drug.

Monitor Closely (1) chloroquine increases toxicity of ondansetron by QTc interval. Use Caution/Monitor.

Serious - Use Alternative (1) chlorpromazine and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Minor (1) cigarette smoking will decrease the level or effect of ondansetron by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.

Serious - Use Alternative (1) ciprofloxacin and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Serious - Use Alternative (2) citalopram and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias. ondansetron, citalopram. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

Serious - Use Alternative (2) clarithromycin and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias. Potential for increased ondansetron levels. clarithromycin will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

Serious - Use Alternative (2) clomipramine and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias. ondansetron, clomipramine. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

Serious - Use Alternative (1) clozapine and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Monitor Closely (1) cobicistat will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

Minor (1) conivaptan will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

Monitor Closely (1) crizotinib increases levels of ondansetron by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.Serious - Use Alternative (1) crizotinib and ondansetron both decrease QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Monitor Closely (1) crofelemer increases levels of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Crofelemer has the potential to inhibit CYP3A4 at concentrations expected in the gut; unlikely to inhibit systemically because minimally absorbed.

Monitor Closely (1) dabrafenib will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely.

Monitor Closely (1) darunavir will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. CYP-450 inhibitors may decrease clearance of ondansetron. However, no dosage adjustment for ondansetron is recommended

Serious - Use Alternative (1) dasatinib and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Monitor Closely (1) deferasirox will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

Serious - Use Alternative (1) degarelix and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Serious - Use Alternative (1) desflurane and ondansetron both increase QTc interval. Avoid or Use Alternate Drug.

Serious - Use Alternative (2) desipramine and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias. ondansetron, desipramine. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

Serious - Use Alternative (1) ondansetron, desvenlafaxine. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

Serious - Use Alternative (1) deutetrabenazine and ondansetron both increase QTc interval. Avoid or Use Alternate Drug.

Monitor Closely (1) dexamethasone will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. No dosage adjustment for ondansetron is recommended for patients on these drugs.

Monitor Closely (1) dichlorphenamide and ondansetron both decrease serum potassium. Use Caution/Monitor.

Minor (1) diltiazem will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown. No dosage adjustment for ondansetron is recommended.

Serious - Use Alternative (1) disopyramide and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Serious - Use Alternative (1) dofetilide and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Serious - Use Alternative (1) dolasetron and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Serious - Use Alternative (1) donepezil and ondansetron both increase QTc interval. Avoid or Use Alternate Drug.

Monitor Closely (1) doxepin and ondansetron both increase QTc interval. Use Caution/Monitor.Serious - Use Alternative (1) ondansetron, doxepin. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

Contraindicated (2) dronedarone will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. dronedarone and ondansetron both increase QTc interval. Contraindicated. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Serious - Use Alternative (1) droperidol and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Serious - Use Alternative (1) ondansetron, duloxetine. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

Monitor Closely (1) efavirenz will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.Serious - Use Alternative (1) efavirenz and ondansetron both increase QTc interval. Avoid or Use Alternate Drug.

Monitor Closely (2) elagolix will increase the level or effect of ondansetron by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. elagolix decreases levels of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Elagolix is a weak-to-moderate CYP3A4 inducer. Monitor CYP3A substrates if coadministered. Consider increasing CYP3A substrate dose if needed.

Serious - Use Alternative (1) ondansetron, eletriptan. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

Monitor Closely (1) eliglustat increases levels of ondansetron by P-glycoprotein (MDR1) efflux transporter. Modify Therapy/Monitor Closely. Monitor therapeutic drug concentrations, as indicated, or consider reducing the dosage of the P-gp substrate and titrate to clinical effect.

Monitor Closely (1) elvitegravir/cobicistat/emtricitabine/tenofovir DF increases levels of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Cobicistat is a CYP3A4 inhibitor; contraindicated with CYP3A4 substrates for which elevated plasma concentrations are associated with serious and/or life-threatening events.

Monitor Closely (1) encorafenib, ondansetron. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Encorafenib both inhibits and induces CYP3A4 at clinically relevant plasma concentrations. Coadministration of encorafenib with sensitive CYP3A4 substrates may result in increased toxicity or decreased efficacy of these agents.Serious - Use Alternative (1) encorafenib and ondansetron both increase QTc interval. Avoid or Use Alternate Drug.

Serious - Use Alternative (1) entrectinib and ondansetron both increase QTc interval. Avoid or Use Alternate Drug.

Serious - Use Alternative (1) enzalutamide will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

Serious - Use Alternative (1) erdafitinib will increase the level or effect of ondansetron by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

Serious - Use Alternative (1) eribulin and ondansetron both increase QTc interval. Avoid or Use Alternate Drug.

Serious - Use Alternative (1) erythromycin base and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Serious - Use Alternative (1) erythromycin ethylsuccinate and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Serious - Use Alternative (1) erythromycin lactobionate and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Serious - Use Alternative (1) erythromycin stearate and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Serious - Use Alternative (2) escitalopram and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias. ondansetron, escitalopram. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

Minor (1) eslicarbazepine acetate will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown. No dosage adjustment for ondansetron is recommended for patients on these drugs.

Minor (1) etravirine will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

Serious - Use Alternative (1) ezogabine and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Monitor Closely (1) fedratinib will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

Monitor Closely (1) ondansetron decreases effects of fenfluramine by pharmacodynamic antagonism. Use Caution/Monitor. Potent serotonin receptor antagonists may decrease fenfluramine efficacy. If coadministered, monitor appropriately.

Serious - Use Alternative (2) fexinidazole and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid coadministration of fexinidazole with drugs known to block potassium channels or prolong QT interval. fexinidazole will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Fexinidazole inhibits CYP3A4. Coadministration may increase risk for adverse effects of CYP3A4 substrates.

Serious - Use Alternative (1) fingolimod and ondansetron both increase QTc interval. Avoid or Use Alternate Drug.

Serious - Use Alternative (1) flecainide and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Serious - Use Alternative (1) fluconazole and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias. Combination may increase ondansetron levels.

Serious - Use Alternative (2) fluoxetine and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias. ondansetron, fluoxetine. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

Serious - Use Alternative (1) fluphenazine and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Serious - Use Alternative (1) fluvoxamine and ondansetron both increase serotonin levels. Avoid or Use Alternate Drug.

Serious - Use Alternative (1) formoterol and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Monitor Closely (1) fosamprenavir will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. CYP-450 inhibitors may decrease clearance of ondansetron. However, no dosage adjustment for ondansetron is recommended

Serious - Use Alternative (1) foscarnet and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Minor (1) fosphenytoin will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

Monitor Closely (1) ondansetron and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.

Serious - Use Alternative (1) ondansetron, frovatriptan. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

Monitor Closely (1) gadobenate and ondansetron both increase QTc interval. Use Caution/Monitor.

Serious - Use Alternative (1) gemifloxacin and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Monitor Closely (1) ondansetron and gemtuzumab both increase QTc interval. Use Caution/Monitor.

Serious - Use Alternative (1) gilteritinib and ondansetron both increase QTc interval. Avoid or Use Alternate Drug.

Serious - Use Alternative (1) ondansetron and glasdegib both increase QTc interval. Avoid or Use Alternate Drug. If coadministration unavoidable, monitor for increased risk of QTc interval prolongation.

Monitor Closely (1) glecaprevir/pibrentasvir will increase the level or effect of ondansetron by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

Monitor Closely (1) goserelin increases toxicity of ondansetron by QTc interval. Use Caution/Monitor. Increases risk of torsades de pointes.

Serious - Use Alternative (1) granisetron and ondansetron both increase QTc interval. Avoid or Use Alternate Drug.

Minor (1) grapefruit will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

Minor (1) griseofulvin will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

Serious - Use Alternative (1) haloperidol and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Monitor Closely (1) histrelin increases toxicity of ondansetron by QTc interval. Use Caution/Monitor. Increases risk of torsades de pointes.

Serious - Use Alternative (1) hydroxychloroquine sulfate and ondansetron both increase QTc interval. Avoid or Use Alternate Drug.

Monitor Closely (1) hydroxyzine increases toxicity of ondansetron by QTc interval. Use Caution/Monitor. Increases risk of torsades de pointes.

Serious - Use Alternative (1) ibutilide and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Serious - Use Alternative (1) idelalisib will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Idelalisib is a strong CYP3A inhibitor; avoid coadministration with sensitive CYP3A substrates

Monitor Closely (1) iloperidone increases levels of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Iloperidone is a time-dependent CYP3A inhibitor and may lead to increased plasma levels of drugs predominantly eliminated by CYP3A4.Serious - Use Alternative (1) iloperidone and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Serious - Use Alternative (1) ondansetron, imipramine. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

Serious - Use Alternative (1) indacaterol, inhaled, ondansetron. QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Serious - Use Alternative (1) indapamide and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Monitor Closely (1) indinavir will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. CYP-450 inhibitors may decrease clearance of ondansetron. However, no dosage adjustment for ondansetron is recommended

Serious - Use Alternative (1) inotuzumab and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. If unable to avoid concomitant use, obtain ECGs and electrolytes before and after initiation of any drug known to prolong QTc, and periodically monitor as clinically indicated during treatment.

Serious - Use Alternative (1) ondansetron, isocarboxazid. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

Serious - Use Alternative (1) isoflurane and ondansetron both increase QTc interval. Avoid or Use Alternate Drug.

Monitor Closely (2) isoniazid will increase the level or effect of ondansetron by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor. CYP-450 inhibitors may decrease clearance of ondansetron. However, no dosage adjustment for ondansetron is recommended isoniazid will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. CYP-450 inhibitors may decrease clearance of ondansetron. However, no dosage adjustment for ondansetron is recommended

Serious - Use Alternative (1) isradipine and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Monitor Closely (2) istradefylline will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Istradefylline 40 mg/day increased peak levels and AUC of CYP3A4 substrates in clinical trials. This effect was not observed with istradefylline 20 mg/day. Consider dose reduction of sensitive CYP3A4 substrates. istradefylline will increase the level or effect of ondansetron by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Istradefylline 40 mg/day increased peak levels and AUC of P-gp substrates in clinical trials. Consider dose reduction of sensitive P-gp substrates.

Monitor Closely (1) itraconazole will increase the level or effect of ondansetron by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. P-gp inhibitors may decrease clearance of ondansetron. No dosage adjustment for ondansetron is recommendedSerious - Use Alternative (1) itraconazole and ondansetron both increase QTc interval. Avoid or Use Alternate Drug.

Monitor Closely (1) ivacaftor increases levels of ondansetron by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Ivacaftor and its M1 metabolite has the potential to inhibit P-gp; may significantly increase systemic exposure to sensitive P-gp substrates with a narrow therapeutic index.

Serious - Use Alternative (1) ivosidenib will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of sensitive CYP3A4 substrates with ivosidenib or replace with alternative therapies. If coadministration is unavoidable, monitor patients for loss of therapeutic effect of these drugs.

Monitor Closely (1) ketoconazole will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. CYP-450 inhibitors may decrease clearance of ondansetron. However, no dosage adjustment for ondansetron is recommended

Serious - Use Alternative (1) lapatinib and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias. Potential for increased ondansetron levels.

Serious - Use Alternative (1) lasmiditan increases levels of ondansetron by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug.

Contraindicated (1) lefamulin will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Lefamulin is contraindicated with CYP3A substrates know to prolong the QT interval.

Monitor Closely (1) ondansetron and lenvatinib both increase QTc interval. Use Caution/Monitor. Lenvatinib prescribing information recommends monitoring ECG closely when coadministered with QT prolonging drugs.

Monitor Closely (1) letermovir increases levels of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

Monitor Closely (1) leuprolide increases toxicity of ondansetron by QTc interval. Use Caution/Monitor. Increases risk of torsades de pointes.

Serious - Use Alternative (1) levofloxacin and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Monitor Closely (1) levoketoconazole will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. CYP-450 inhibitors may decrease clearance of ondansetron. However, no dosage adjustment for ondansetron is recommended

Serious - Use Alternative (1) ondansetron, levomilnacipran. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

Serious - Use Alternative (1) lithium and ondansetron both increase QTc interval. Avoid or Use Alternate Drug.

Monitor Closely (1) lomitapide increases levels of ondansetron by P-glycoprotein (MDR1) efflux transporter. Modify Therapy/Monitor Closely. Consider reducing dose when used concomitantly with lomitapide.

Monitor Closely (1) lonafarnib will increase the level or effect of ondansetron by P-glycoprotein (MDR1) efflux transporter. Modify Therapy/Monitor Closely. Lonafarnib is a weak P-gp inhibitor. Monitor for adverse reactions if coadministered with P-gp substrates where minimal concentration changes may lead to serious or life-threatening toxicities. Reduce P-gp substrate dose if needed.

Monitor Closely (1) lopinavir and ondansetron both increase QTc interval. Use Caution/Monitor. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.Serious - Use Alternative (1) lopinavir will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

Monitor Closely (1) lorlatinib will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

Serious - Use Alternative (1) lumefantrine and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Serious - Use Alternative (1) macimorelin and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Macimorelin causes an increase of ~11 msec in the corrected QT interval. Avoid coadministration with drugs that prolong QT interval, which could increase risk for developing torsade de pointes-type ventricular tachycardia. Allow sufficient washout time of drugs that are known to prolong the QT interval before administering macimorelin.

Serious - Use Alternative (1) maprotiline and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Serious - Use Alternative (1) mefloquine and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Monitor Closely (1) ondansetron increases levels of metformin by Other (see comment). Use Caution/Monitor. Comment: Ondansetron inhibition of transporters (MATE or OCTs), which are responsible for active renal secretion of metformin may play a role.

Serious - Use Alternative (1) methadone and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Minor (1) mexiletine will increase the level or effect of ondansetron by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.

Monitor Closely (1) mifepristone, ondansetron. QTc interval. Modify Therapy/Monitor Closely. Use alternatives if available.Serious - Use Alternative (1) mifepristone will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

Serious - Use Alternative (1) ondansetron, milnacipran. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

Monitor Closely (1) mitotane decreases levels of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Mitotane is a strong inducer of cytochrome P-4503A4; monitor when coadministered with CYP3A4 substrates for possible dosage adjustments.

Serious - Use Alternative (1) mobocertinib and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. If coadministration unavoidable, reduce mobocertinib dose and monitor QTc interval more frequently.

Minor (1) modafinil will decrease the level or effect of ondansetron by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.

Serious - Use Alternative (1) moxifloxacin and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Minor (1) nafcillin will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

Serious - Use Alternative (1) ondansetron, naratriptan. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

Monitor Closely (1) nefazodone will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. CYP-450 inhibitors may decrease clearance of ondansetron. However, no dosage adjustment for ondansetron is recommended

Monitor Closely (1) nelfinavir will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. CYP-450 inhibitors may decrease clearance of ondansetron. However, no dosage adjustment for ondansetron is recommended

Minor (1) nevirapine will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

Serious - Use Alternative (1) nilotinib and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias. Potential for increased ondansetron levels.

Serious - Use Alternative (2) nortriptyline and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias. ondansetron, nortriptyline. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

Serious - Use Alternative (1) octreotide and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Serious - Use Alternative (1) ofloxacin and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Serious - Use Alternative (1) olanzapine and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Monitor Closely (1) osilodrostat and ondansetron both increase QTc interval. Use Caution/Monitor.

Monitor Closely (1) osimertinib and ondansetron both increase QTc interval. Use Caution/Monitor. Conduct periodic monitoring with ECGs and electrolytes in patients taking drugs known to prolong the QTc interval.

Monitor Closely (1) oxaliplatin will increase the level or effect of ondansetron by Other (see comment). Use Caution/Monitor. Monitor for ECG changes if therapy is initiated in patients with drugs known to prolong QT interval.Serious - Use Alternative (1) oxaliplatin and ondansetron both increase QTc interval. Avoid or Use Alternate Drug.

Monitor Closely (1) oxcarbazepine will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. No dosage adjustment for ondansetron is recommended for patients on these drugs.

Monitor Closely (1) ozanimod and ondansetron both increase QTc interval. Modify Therapy/Monitor Closely. The potential additive effects on heart rate, treatment with ozanimod should generally not be initiated in patients who are concurrently treated with QT prolonging drugs with known arrhythmogenic properties.

Serious - Use Alternative (1) paliperidone and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Monitor Closely (1) ondansetron and panobinostat both increase QTc interval. Modify Therapy/Monitor Closely. Panobinostat is known to significantly prolong QT interval. Panobinostat prescribing information states use with drugs known to prolong QTc is not recommended; however, antiemetic drugs known to prolong QTc (eg, dolasetron, granisetron, ondansetron) can be used with frequent ECG monitoring.

Serious - Use Alternative (1) ondansetron, paroxetine. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

Monitor Closely (1) ondansetron and pasireotide both increase QTc interval. Modify Therapy/Monitor Closely.

Serious - Use Alternative (1) pazopanib and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Minor (1) peginterferon alfa 2a will increase the level or effect of ondansetron by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.

Serious - Use Alternative (1) pentamidine and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Monitor Closely (1) pentobarbital will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. No dosage adjustment for ondansetron is recommended for patients on these drugs.Minor (1) pentobarbital will decrease the level or effect of ondansetron by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.

Serious - Use Alternative (1) perphenazine and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Serious - Use Alternative (1) ondansetron, phenelzine. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

Monitor Closely (1) phenobarbital will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. No dosage adjustment for ondansetron is recommended for patients on these drugs.Minor (1) phenobarbital will decrease the level or effect of ondansetron by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.

Monitor Closely (1) phenytoin will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. No dosage adjustment for ondansetron is recommended for patients on these drugs.

Serious - Use Alternative (1) pimozide and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Serious - Use Alternative (1) ondansetron and pitolisant both increase QTc interval. Avoid or Use Alternate Drug.

Monitor Closely (1) ponatinib increases levels of ondansetron by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

Contraindicated (1) posaconazole will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.Serious - Use Alternative (1) posaconazole and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias. Potential for increased ondansetron levels.

Serious - Use Alternative (1) primaquine and ondansetron both increase QTc interval. Avoid or Use Alternate Drug.

Minor (2) primidone will decrease the level or effect of ondansetron by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown. primidone will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

Serious - Use Alternative (1) procainamide and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Serious - Use Alternative (1) propafenone and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Serious - Use Alternative (2) protriptyline and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias. ondansetron, protriptyline. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

Serious - Use Alternative (1) quetiapine and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Serious - Use Alternative (1) quinidine and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Serious - Use Alternative (1) quinine and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Serious - Use Alternative (1) ranolazine and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Serious - Use Alternative (1) ondansetron, rasagiline. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

Monitor Closely (1) ribociclib will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.Serious - Use Alternative (1) ribociclib and ondansetron both increase QTc interval. Avoid or Use Alternate Drug.

Monitor Closely (1) rifabutin will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

Monitor Closely (1) rifampin will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.Minor (1) rifampin will decrease the level or effect of ondansetron by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.

Minor (1) rifapentine will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

Serious - Use Alternative (1) ondansetron and risperidone both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Monitor Closely (2) ritonavir and ondansetron both increase QTc interval. Use Caution/Monitor. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias. May increase ondansetron levels. ritonavir will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

Serious - Use Alternative (1) ondansetron, rizatriptan. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

Serious - Use Alternative (1) ondansetron and romidepsin both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Monitor Closely (1) rucaparib will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Adjust dosage of CYP3A4 substrates, if clinically indicated.

Serious - Use Alternative (2) ondansetron and saquinavir both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias. saquinavir will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

Monitor Closely (1) sarecycline will increase the level or effect of ondansetron by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Monitor for toxicities of P-gp substrates that may require dosage reduction when coadministered with P-gp inhibitors.

Monitor Closely (1) secobarbital will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. No dosage adjustment for ondansetron is recommended for patients on these drugs.

Serious - Use Alternative (1) ondansetron, selegiline. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

Serious - Use Alternative (1) ondansetron, selegiline transdermal. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

Monitor Closely (1) selpercatinib increases toxicity of ondansetron by QTc interval. Use Caution/Monitor.

Serious - Use Alternative (2) ondansetron and sertraline both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias. ondansetron, sertraline. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

Serious - Use Alternative (1) sevoflurane and ondansetron both increase QTc interval. Avoid or Use Alternate Drug.

Serious - Use Alternative (1) ondansetron and solifenacin both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Monitor Closely (1) sorafenib and ondansetron both increase QTc interval. Use Caution/Monitor.

Serious - Use Alternative (1) ondansetron and sotalol both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Serious - Use Alternative (1) sotorasib will decrease the level or effect of ondansetron by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If use is unavoidable, refer to the prescribing information of the P-gp substrate for dosage modifications.

Monitor Closely (1) St John's Wort will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

Monitor Closely (2) stiripentol, ondansetron. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Stiripentol is a CYP3A4 inhibitor and inducer. Monitor CYP3A4 substrates coadministered with stiripentol for increased or decreased effects. CYP3A4 substrates may require dosage adjustment. stiripentol will increase the level or effect of ondansetron by P-glycoprotein (MDR1) efflux transporter. Modify Therapy/Monitor Closely. Consider reducing the dose of P-glycoprotein (P-gp) substrates, if adverse reactions are experienced when administered concomitantly with stiripentol.

Serious - Use Alternative (1) ondansetron, sumatriptan. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

Serious - Use Alternative (1) ondansetron, sumatriptan intranasal. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

Serious - Use Alternative (1) ondansetron and sunitinib both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Serious - Use Alternative (1) ondansetron and tacrolimus both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Monitor Closely (1) tazemetostat will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

Monitor Closely (1) tecovirimat will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Tecovirimat is a weak CYP3A4 inducer. Monitor sensitive CYP3A4 substrates for effectiveness if coadministered.

Serious - Use Alternative (1) tedizolid, ondansetron. Either increases effects of the other by Mechanism: pharmacodynamic synergism. Avoid or Use Alternate Drug. both increase serotonin levels; increased risk of serotonin syndrome.

Serious - Use Alternative (1) ondansetron and telavancin both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Serious - Use Alternative (1) tepotinib will increase the level or effect of ondansetron by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If concomitant use unavoidable, reduce the P-gp substrate dosage if recommended in its approved product labeling.

Serious - Use Alternative (1) thioridazine and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Serious - Use Alternative (1) ondansetron and thiothixene both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Minor (1) topiramate will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

Serious - Use Alternative (1) ondansetron and toremifene both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Serious - Use Alternative (1) ondansetron, tranylcypromine. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

Monitor Closely (1) triclabendazole and ondansetron both increase QTc interval. Use Caution/Monitor.

Serious - Use Alternative (2) ondansetron and trimipramine both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias. ondansetron, trimipramine. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

Monitor Closely (1) triptorelin increases toxicity of ondansetron by QTc interval. Use Caution/Monitor. Increases risk of torsades de pointes.

Monitor Closely (1) tucatinib will increase the level or effect of ondansetron by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Consider reducing the dosage of P-gp substrates, where minimal concentration changes may lead to serious or life-threatening toxicities.Serious - Use Alternative (1) tucatinib will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid concomitant use of tucatinib with CYP3A substrates, where minimal concentration changes may lead to serious or life-threatening toxicities. If unavoidable, reduce CYP3A substrate dose according to product labeling.

Serious - Use Alternative (1) ondansetron increases toxicity of umeclidinium bromide/vilanterol inhaled by QTc interval. Avoid or Use Alternate Drug. Exercise extreme caution when vilanterol coadministered with drugs that prolong QTc interval; adrenergic agonist effects on the cardiovascular system may be potentiated.

Serious - Use Alternative (1) vandetanib and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Serious - Use Alternative (1) ondansetron and vardenafil both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Serious - Use Alternative (1) ondansetron and vemurafenib both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias. Alterations in ondansetron concentrations may occur with concomitant use.

Serious - Use Alternative (1) ondansetron, venlafaxine. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

Minor (2) verapamil will increase the level or effect of ondansetron by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown. verapamil will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

Serious - Use Alternative (1) ondansetron increases toxicity of vilanterol/fluticasone furoate inhaled by QTc interval. Avoid or Use Alternate Drug. Exercise extreme caution when vilanterol coadministered with drugs that prolong QTc interval; adrenergic agonist effects on the cardiovascular system may be potentiated.

Monitor Closely (1) voclosporin, ondansetron. Either increases effects of the other by QTc interval. Use Caution/Monitor.

Serious - Use Alternative (2) ondansetron and voriconazole both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias. Potential for increased ondansetron levels. voriconazole will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

Serious - Use Alternative (1) ondansetron and vorinostat both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Serious - Use Alternative (1) voxelotor will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Voxelotor increases systemic exposure of sensitive CYP3A4 substrates. Avoid coadministration with sensitive CYP3A4 substrates with a narrow therapeutic index. Consider dose reduction of the sensitive CYP3A4 substrate(s) if unable to avoid.

Minor (1) zileuton will increase the level or effect of ondansetron by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown. No dosage adjustment is needed for ondansetron.

Serious - Use Alternative (1) ziprasidone and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

Serious - Use Alternative (1) ondansetron, zolmitriptan. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

Elevated liver function test results (1-5%)

Cardiac: Arrhythmias (including ventricular and supraventricular tachycardia, premature ventricular contractions, and atrial fibrillation), bradycardia, electrocardiographic alterations (including second-degree heart block, QT/QTc interval prolongation, and ST segment depression), palpitations, and syncope; rarely and predominantly with intravenous ondansetron, myocardial ischemia, transient ECG changes including QT/QTc interval prolongation have been reported

ECG alterations: Arrhythmias; prolongation of PR, QRS, and QT intervals

Hepatobiliary: Specific hepatic enzyme abnormalities, hepatic necrosis, and abnormal hepatic function

General: Flushing, rare cases of hypersensitivity reactions, sometimes severe (eg, anaphylactic reactions, angioedema, bronchospasm, cardiopulmonary arrest, hypotension, laryngeal edema, laryngospasm, shock, shortness of breath, stridor)

Local reactions: Pain, redness, and burning at injection site

Neurological: Oculogyric crisis, appearing alone, as well as with other dystonic reactions; transient dizziness during or shortly after intravenous infusion

Skin and subcutaneous tissue: Urticaria, Stevens-Johnson syndrome, and toxic epidermal necrolysis

Eye Disorders: Transient blindness (predominantly during IV administration) reported to resolve within a few minutes up to 48 hr; transient blurred vision

Musculoskeletal and connective tissue: Arthralgia

Coadministration with apomorphine; combination reported to cause profound hypotension and loss of consciousness

Hypersensitivity reactions including anaphylaxis and bronchospasm may occur: discontinue therapy if suspected; monitor and treat promptly per standard of care until signs and symptoms resolve

Reduce dose with severe hepatic impairment

Use according to schedule, not PRN

Do not use instead of nasogastric suction

Ondansetron may mask progressive ileus or gastric distention in patients who are undergoing abdominal surgery or experiencing chemotherapy-induced nausea and vomiting; monitor for decreased bowel activity, particularly in patients with risk factors for gastrointestinal obstruction

Ondansetron is not a drug that stimulates gastric or intestinal peristalsis; should not be used instead of nasogastric suction

Serotonin syndrome reported with 5-HT3 receptor antagonists alone but particularly with concomitant use of serotonergic drugs including SSRIs, SNRIs, MAO inhibitors, lithium, tramadol, methylene blue IV, and mirtazapine; if concomitant use with other serotonergic drugs is clinically warranted, patients should be made aware of potential increased risk for serotonin syndrome

Cross-sensitivity among selective serotonin antagonists may occur

Zofran ODT contains phenylalanine (caution for phenylketonurics)

Dose-dependent QT prolongation; avoid in patients with congenital long QT syndrome; ECG monitoring recommended in patients who have electrolyte abnormalities, CHF, or bradyarrhythmias or who are also receiving other medications that cause QT prolongation

Published epidemiological studies on association between ondansetron use and major birth defects have reported inconsistent findings and have important methodological limitations that preclude conclusions about safety use in pregnancy

Available postmarketing data have not identified a drug-associated risk of miscarriage or adverse maternal outcomes

Reproductive studies in rats and rabbits did not show evidence of harm to fetus when ondansetron was administered during organogenesis at approximately 6 and 24 times maximum recommended human oral dose of 24 mg/day, based on body surface area, respectively

Not known whether ondansetron is present in human milk; there are no data on effects of therapy on breastfed infant or effects on milk production; however, it has been demonstrated that the drug is present in milk of rats; when a drug is present in animal milk, it is likely that the drug will be present in human milk

The developmental and health benefits of breastfeeding should be considered along with mother’s clinical need for drug and any potential adverse effects on breastfed infant from therapy or from underlying maternal condition

A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.

Mechanism not fully characterized; selective 5-HT3 receptor antagonist; binds to 5-HT3 receptors both in periphery and in CNS, with primary effects in GI tract

Has no effect on dopamine receptors and therefore does not cause extrapyramidal symptoms

Bioavailability: 56-71% (PO); food increases extent of absorption (17%)

Peak plasma time: IV, end of infusion; IM, 30 min; PO, 2 hr (tablet) or 1 hr (soluble film)

Vd: Children, 1.7-3.7 L/kg; adults, 2.2-2.5 L/kg

Extensive hepatic metabolism, with hydroxylation followed by glucuronide (indole ring) or sulfate conjugation; metabolized by CYP2D6 and partly by CYP1A2 and CYP3A4

Metabolites: Glucuronide conjugate, sulfate conjugate (inactive)

Half-life: 2-7 hr (children <15 years); 3-7 hr (adults); patients with mild to moderate hepatic impairment, 12 hr; patients with severe hepatic impairment (Child-Pugh class C), 20 hr

Renal Clearance: 0.26-0.38 L/hr/kg

Total body clearance: 600-700 mL/min

Excretion: Primarily urine (30-70%); feces (25%)

Y-site: Acyclovir, allopurinol, aminophylline, amphotericin B, amphotericin B cholesteryl sulfate, ampicillin, ampicillin/sulbactam, amsacrine, cefepime, cefoperazone, 5-fluorouracil (5-FU; at 1 mg/mL ondansetron and 16 mg/mL 5-FU; may be compatible at 0.8 mg/mL 5-FU and up to 160 mcg/mL ondansetron), furosemide, ganciclovir, lorazepam, meropenem (at 50 mg/mL meropenem and 1 mg/mL ondansetron; may be compatible at 1 mg/mL each), methylprednisolone, piperacillin, sargramostim, sodium bicarbonate

Solution: Compatible with most common solvents

Additive (partial list): Cisplatin, cyclophosphamide, cytarabine, decarbazine, dacarbazine with doxorubicin(?), doxorubicin, etoposide, hydromorphone, meropenem (incompatible at 20 g/L meropenem), methotrexate, morphine sulfate

Syringe: Alfentanil, atropine, dexamethasone (incompatible at 0.67 mg/mL dexamethasone and 1.07 mg/mL ondansetron), fentanyl, glycopyrrolate, meperidine, metoclopramide, midazolam, morphine sulfate, naloxone, neostigmine, propofol

Y-site (partial list): Alatrofloxacin, aldesleukin, azithromycin, bleomycin, carboplatin, cisplatin, cladribine, clindamycin, cyclophosphamide, cytarabine, dactinomycin, dopamine, heparin, hydromorphone, magnesium sulfate, meperidine, morphine sulfate, paclitaxel, potassium chloride, topotecan, vancomycin, vinblastine, vincristine, zidovudine

No dilution necessary for premixed injection

Postoperative nausea and vomiting: No dilution necessary for 2 mg/mL vials

Chemotherapy-induced nausea and vomiting: Dilute IV injection (2 mg/mL vials, not premixed injection) in 50 mL D5W or NS

Infuse over 15 minutes after further dilution with 50 mL NS/D5W

Inject undiluted over at least 30 seconds, preferably over 2-5 minutes

No dilution necessary for premixed injection

Store at room temperature or refrigerate

Protect from light, excessive heat, and freezing

Copyright © 2010 First DataBank, Inc.

ONDANSETRON SOLUBLE FILM - ORAL

COMMON BRAND NAME(S): Zuplenz

USES: This medication is used alone or with other medications to prevent nausea and vomiting caused by cancer drug treatment (chemotherapy), radiation treatment, or drugs used to put you to sleep before surgery. Ondansetron works by blocking one of the body's natural substances (serotonin) that causes vomiting.

HOW TO USE: Read the Patient Information Leaflet and Instructions for Use if available from your pharmacist before you start using ondansetron oral soluble film and each time you get a refill. If you have any questions, ask your doctor or pharmacist.This medication is made to be dissolved on top of your tongue. Do not chew or swallow the film whole. If giving this medicine to a young child, help them use it properly.With dry hands, open the protective foil pouch just before using. Remove one film and place on top of your tongue. Allow it to dissolve completely (usually in 4 to 20 seconds), then swallow it with saliva or with liquid. You do not need to take this product with liquid. If your dose is for more than one film, allow each film to dissolve completely before taking the next film. Wash your hands after taking this medication.To prevent nausea from chemotherapy, take this medication as directed by your doctor, usually 30 minutes before treatment begins. To prevent nausea from radiation treatment, take this medication 1 to 2 hours before the start of your treatment. To prevent nausea after surgery, take ondansetron 1 hour before the start of surgery.Carefully follow your doctor's directions for taking this medication. Ondansetron may be taken up to 3 times a day for 1 to 2 days after each chemotherapy or radiation treatment. If you are taking this medication on a prescribed schedule, take it regularly in order to get the most benefit from it. To help you remember, take it at the same times each day.The dosage is based on your medical condition and response to treatment. The dosage for children may also be based on age and weight. Take this medication exactly as directed. Do not take more medication or take it more often than prescribed.Tell your doctor if your nausea and vomiting lasts or if it gets worse.

SIDE EFFECTS: Headache, lightheadedness, dizziness, drowsiness, tiredness, or constipation may occur. If these effects last or get worse, tell your doctor promptly.To minimize dizziness and lightheadedness, get up slowly when rising from a sitting or lying position.Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.Tell your doctor right away if you have any serious side effects, including: abdominal pain, muscle spasm/stiffness.Get medical help right away if you have any very serious side effects, including: chest pain, slow/fast/irregular heartbeat, severe dizziness, fainting.This medication may increase serotonin and rarely cause a very serious condition called serotonin syndrome/toxicity. The risk increases if you are also taking other drugs that increase serotonin, so tell your doctor or pharmacist of all the drugs you take (see Drug Interactions section). Get medical help right away if you develop some of the following symptoms: fast heartbeat, hallucinations, loss of coordination, severe dizziness, severe nausea/vomiting/diarrhea, twitching muscles, unexplained fever, unusual agitation/restlessness.A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.In the US -Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

PRECAUTIONS: Before taking ondansetron, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.Before using this medication, tell your doctor or pharmacist your medical history, especially of: irregular heartbeat, liver problems, stomach/intestinal problems (such as recent abdominal surgery, ileus).Ondansetron may cause a condition that affects the heart rhythm (QT prolongation). QT prolongation can rarely cause serious (rarely fatal) fast/irregular heartbeat and other symptoms (such as severe dizziness, fainting) that need medical attention right away.The risk of QT prolongation may be increased if you have certain medical conditions or are taking other drugs that may cause QT prolongation. Before using ondansetron, tell your doctor or pharmacist of all the drugs you take and if you have any of the following conditions: certain heart problems (heart failure, slow heartbeat, QT prolongation in the EKG), family history of certain heart problems (QT prolongation in the EKG, sudden cardiac death).Low levels of potassium or magnesium in the blood may also increase your risk of QT prolongation. This risk may increase if you use certain drugs (such as diuretics/"water pills") or if you have conditions such as severe sweating, diarrhea, or vomiting. Talk to your doctor about using ondansetron safely.This drug may make you dizzy or drowsy. Alcohol or marijuana (cannabis) can make you more dizzy or drowsy. Do not drive, use machinery, or do anything that needs alertness until you can do it safely. Avoid alcoholic beverages. Talk to your doctor if you are using marijuana (cannabis).Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).Older adults may be more sensitive to the side effects of this drug, especially QT prolongation (see above).During pregnancy, this medication should be used only when clearly needed. It may harm an unborn baby. Discuss the risks and benefits with your doctor.It is unknown if this drug passes into breast milk. Consult your doctor before breast-feeding.

DRUG INTERACTIONS: Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.Some products that may interact with this drug include: apomorphine, tramadol.Many drugs besides ondansetron may affect the heart rhythm (QT prolongation), including dofetilide, pimozide, procainamide, amiodarone, quinidine, sotalol, macrolide antibiotics (such as erythromycin), among others. Before using ondansetron, report all medications you are currently using to your doctor or pharmacist.The risk of serotonin syndrome/toxicity increases if you are also taking other drugs that increase serotonin. Examples include street drugs such as MDMA/"ecstasy," St. John's wort, certain antidepressants (including SSRIs such as fluoxetine/paroxetine, SNRIs such as duloxetine/venlafaxine), among others. The risk of serotonin syndrome/toxicity may be more likely when you start or increase the dose of these drugs.

OVERDOSE: If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center.

NOTES: Do not share this product with others.Laboratory and/or medical tests (such as EKG) should be performed periodically to monitor your progress or check for side effects. Consult your doctor for more details.

MISSED DOSE: Try to take each dose at the scheduled time. If you miss a dose, take it as soon as you remember unless it is near the time for the next dose. In that case, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up.

STORAGE: Store at room temperature away from light and moisture. Do not store in the bathroom. Keep all medications out of reach of children and pets.Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.

Information last revised February 2022. Copyright(c) 2022 First Databank, Inc.

IMPORTANT: HOW TO USE THIS INFORMATION: This is a summary and does NOT have all possible information about this product. This information does not assure that this product is safe, effective, or appropriate for you. This information is not individual medical advice and does not substitute for the advice of your health care professional. Always ask your health care professional for complete information about this product and your specific health needs.

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