Ondansetron has 20 known drug interactions based on U.S. FDA drug labeling data. Of these, 2 are contraindicated combinations that should be avoided entirely. 2 are classified as major interactions requiring close medical supervision. Notable interactions include combinations with Apomorphine, Apomorphine Hydrochloride, Selective Serotonin Reuptake Inhibitors (Ssri). 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
- 20
- Contraindicated
- 2
- Major
- 2
- 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 (2)
- 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.