Ondansetron

84 interactions 6 explained in plain English
Dr. Brian Staiger, PharmD, BCPS
Medically reviewed by Dr. Brian Staiger, PharmD, BCPS · Updated Jul 4, 2026 · Editorial policy · Data sources

Sources: FDA prescribing information (Structured Product Labeling), the published literature cited in each entry, DDInter 2.0 (a major open-access drug-interaction database), and legacy DrugBank interaction data distributed by the NIH's RxNav service (decommissioned in 2024) — analyzed and reviewed by our pharmacist team. How we build this library →

Most serious with: Ketoconazole Topical Encorafenib Morphine Injection Granisetron Injection Capmatinib Palonosetron Injection
1 Contraindicated 81 Major 2 Moderate
All (84) Contraindicated (1) Major (81) Moderate (2)

Contraindicated

Ondansetron Ketoconazole Topical Extina® Foam Increased CYP3A4 substrate exposure and an increased risk of QT interval prolongation Details

Major

Ondansetron Acetaminophen And Codeine Capital® & Codeine Explained Increased risk of serotonin syndrome Details Ondansetron Abametapir Explained Increased exposure of CYP3A4 substrate Details Ondansetron Amitriptyline Elavil Explained An increased risk of serotonin syndrome and QT interval prolongation Details Ondansetron Sertraline Explained Increased CYP2D6 substrate exposure, an increased risk of serotonin syndrome and an increased risk of QT interval prolongation Details Ondansetron Buprenorphine Belbuca Explained An increased risk of serotonin syndrome and QT interval prolongation Details Ondansetron Relugolix Orgovyx Explained Increased risk of QT interval prolongation Details Ondansetron Amisulpride Injection Barhemsys Increased risk of serious ventricular arrhythmias such as torsades de pointes Details Ondansetron Arsenic Trioxide Trisenox An increased risk of cardiotoxicity (QT prolongation, torsades de pointes, cardiac arrest) Details Ondansetron Aripiprazole Injection Abilify An increased risk of QT interval prolongation Details Ondansetron Arsenic Trioxide Injection Trisenox An increased risk of cardiotoxicity (QT prolongation, torsades de pointes, cardiac arrest) Details Ondansetron Asenapine Transdermal Patch Secuado An increased risk of QT interval prolongation Details Ondansetron Azathioprine Azasan An increased risk of hepatotoxicity Details Ondansetron Azithromycin AzaSite An increased risk of QT interval prolongation Details Ondansetron Abiraterone Abirtega Increased CYP2D6 substrate exposure and an increased risk of CYP2D6 substrate-related adverse effects Details Ondansetron Alfuzosin UroXatral An increased risk of QT interval prolongation Details Ondansetron Anagrelide Agrylin An increased risk of QT interval prolongation Details Ondansetron Bedaquiline Sirturo Increased risk of QT interval prolongation Details Ondansetron Butorphanol Injection Butorphic Increased risk of serotonin syndrome Details Ondansetron Butorphanol Nasal Spray Stadol® NS Increased risk of serotonin syndrome Details Ondansetron Capmatinib Tabrecta Increased CYP1A2 substrate exposure and an increased risk of adverse reactions Details Ondansetron Chloroquine Aralen® An increased risk of QT interval prolongation Details Ondansetron Dasatinib Phyrago An increased risk of QT interval prolongation Details Ondansetron Degarelix Injection Firmagon Increased risk of QT interval prolongation Details Ondansetron Deutetrabenazine Austedo An increased risk of QT interval prolongation Details Ondansetron Disopyramide Norpace An increased risk of QT interval prolongation Details Ondansetron Dofetilide Tikosyn An increased risk of cardiotoxicity (QT prolongation, torsades de pointes, cardiac arrest) Details Ondansetron Dolasetron Anzemet An increased risk of serotonin syndrome and QT interval prolongation Details Ondansetron Dolasetron Injection Anzemet An increased risk of serotonin syndrome and QT interval prolongation Details Ondansetron Encorafenib Braftovi Increased risk of QT interval prolongation Details Ondansetron Entrectinib Rozlytrek An increased risk of QT interval prolongation Details Ondansetron Eribulin Injection Halaven An increased risk of QT interval prolongation Details Ondansetron Famotidine Calmicid An increased risk of QT interval prolongation Details Ondansetron Famotidine Injection Calmicid An increased risk of QT interval prolongation Details Ondansetron Felbamate Felbatol An increased risk of QT interval prolongation Details Ondansetron Fentanyl Transdermal Patch Duragesic® Increased risk of serotonin syndrome Details Ondansetron Flecainide Tambocor® An increased risk of QT interval prolongation Details Ondansetron Foscarnet Injection Foscavir An increased risk of QT interval prolongation Details Ondansetron Fostemsavir Rukobia Increased risk of torsade de pointes Details Ondansetron Galantamine Razadyne An increased risk of QT interval prolongation Details

Check another drug

Still have questions about this combination?

Every question gets a real answer from a licensed pharmacist — free, and usually within a day.

Ask the pharmacist
Educational information only, not medical advice. Always confirm interactions with your pharmacist or prescriber before making any change to your medications.