Ondansetron has 21 known drug interactions based on U.S. FDA drug labeling data. Of these, 2 are contraindicated combinations that should be avoided entirely. 3 are classified as major interactions requiring close medical supervision. Notable interactions include combinations with Apomorphine, Apomorphine Hydrochloride, Amiodarone. Patients taking Ondansetron should inform their healthcare provider of all current medications — including over-the-counter drugs and supplements — to avoid potentially harmful combinations. Data sourced from OpenFDA and the NIH National Library of Medicine.
- Total
- 21
- Contraindicated
- 2
- Major
- 3
- Moderate
- 9
- Minor
- 7
Contraindicated (2)
- Ondansetron + Apomorphine— 7.2 Apomorphine Based on reports of profound hypotension and loss of consciousness when apomorphine was administered wit…
- Ondansetron + Apomorphine Hydrochloride— Concomitant use with apomorphine hydrochloride is contraindicated due to reports of profound hypotension and loss of con…
Major (3)
- Ondansetron + Amiodarone— Both ondansetron and amiodarone prolong the QT interval; used together they raise the risk of QT prolongation and torsad…
- Ondansetron + Selective Serotonin Reuptake Inhibitors (Ssri)— Concomitant use may cause serotonin syndrome including altered mental status, autonomic instability, and neuromuscular s…
- Ondansetron + Toremifene Citrate— Anti-emetic that prolongs QT interval; should be avoided with toremifene citrate or requires close monitoring.
Moderate (9)
- Ondansetron + Amisulpride— Ondansetron is known to prolong QT interval; ECG monitoring recommended when used with amisulpride.
- Ondansetron + Anagrelide— Anagrelide may increase ondansetron exposure as a CYP1A2 substrate; monitor accordingly.
- Ondansetron + Anagrelide Hydrochloride— Limited CYP1A2 inhibitory activity may alter ondansetron exposure; monitor accordingly.
- Ondansetron + Carbamazepine— Potent CYP3A4 inducer significantly increases ondansetron clearance and decreases blood concentrations. Monitor for redu…
- Ondansetron + Phenytoin— Potent CYP3A4 inducer significantly increases ondansetron clearance and decreases blood concentrations. Monitor for redu…
- Ondansetron + Quizartinib— QT interval prolonging drug. Coadministration with VANFLYTA may further increase incidence of QT prolongation. More freq…
- Ondansetron + Rifampin— Potent CYP3A4 inducer significantly increases ondansetron clearance and decreases blood concentrations. Monitor for redu…
- Ondansetron + Sumatriptan Succinate— Serotonin syndrome including altered mental status, autonomic instability, and neuromuscular symptoms has been described…
- Ondansetron + Tramadol— Ondansetron may increase patient-controlled administration of tramadol. Monitor patients to ensure adequate pain control…
Minor (7)
- Ondansetron + Alfentanil— Ondansetron does not alter the respiratory depressant effects produced by alfentanil.
- Ondansetron + Atracurium— Ondansetron does not alter the degree of neuromuscular blockade produced by atracurium.
- Ondansetron + Carmustine— Carmustine does not affect the pharmacokinetics of ondansetron.
- Ondansetron + Cisplatin— Cisplatin does not affect the pharmacokinetics of ondansetron.
- Ondansetron + Etoposide— Etoposide does not affect the pharmacokinetics of ondansetron.
- Ondansetron + Methotrexate— Intravenous ondansetron does not increase blood levels of high-dose methotrexate in pediatric patients.
- Ondansetron + Temazepam— Ondansetron had no effect on the pharmacokinetics and pharmacodynamics of temazepam.