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)

Major

Ondansetron Gemifloxacin Factive An increased risk of QT interval prolongation Details Ondansetron Glasdegib Daurismo Increased risk of QT interval prolongation Details Ondansetron Goserelin Implant Zoladex Increased risk of QT interval prolongation Details Ondansetron Granisetron Transdermal Patch Sancuso An increased risk of serotonin syndrome and QT interval prolongation Details Ondansetron Granisetron Injection Granisol An increased risk of serotonin syndrome and QT interval prolongation Details Ondansetron Histrelin Implant Supprelin Increased risk of QT interval prolongation Details Ondansetron Hydromorphone Injection Dilaudid Increased risk of serotonin syndrome Details Ondansetron Hydromorphone Rectal available generically Increased risk of serotonin syndrome Details Ondansetron Hydroxychloroquine Plaquenil Increased risk of QT interval prolongation Details Ondansetron Inotuzumab Ozogamicin Injection Besponsa Increased risk of QT interval prolongation Details Ondansetron Isradipine DynaCirc® An increased risk of cardiotoxicity (QT prolongation, torsades de pointes, cardiac arrest) Details Ondansetron Ivabradine Corlanor Increased risk of QT prolongation Details Ondansetron Lefamulin Xenleta Increased risk of QT interval prolongation Details Ondansetron Lenvatinib Lenvima Increased risk of QT-interval prolongation Details Ondansetron Letermovir Injection Prevymis Increased CYP3A substrate exposure Details Ondansetron Levofloxacin Levaquin An increased risk of QT interval prolongation Details Ondansetron Levofloxacin Injection Levaquin An increased risk of QT interval prolongation Details Ondansetron Linezolid Injection Zyvox Increased risk of serotonin syndrome Details Ondansetron Lithium Carbonate Lithobid Increased risk of serotonin syndrome Details Ondansetron Loperamide Diamode An increased risk of QT interval prolongation, which may increase risk of cardiotoxicity (torsade de pointes, cardiac arrest) Details Ondansetron Mefloquine Lariam® An increased risk of QT interval prolongation Details Ondansetron Mercaptopurine Purinethol® An increased risk of hepatotoxicity Details Ondansetron Methotrexate Jylamvo Increased methotrexate exposure, an increased risk of methotrexate-related severe adverse reactions, reduced active metabolite for... Details Ondansetron Methotrexate Injection Abitrexate® Increased methotrexate exposure, an increased risk of methotrexate-related severe adverse reactions, reduced active metabolite for... Details Ondansetron Metronidazole Flagyl An increased risk of QT interval prolongation Details Ondansetron Metronidazole Injection Flagyl An increased risk of QT interval prolongation Details Ondansetron Metronidazole Topical MetroCream® An increased risk of QT interval prolongation Details Ondansetron Metronidazole Vaginal MetroGel® Vaginal An increased risk of QT interval prolongation Details Ondansetron Morphine Injection Astramorph® PF Increased risk of serotonin syndrome Details Ondansetron Moxifloxacin Avelox Increased risk of QT interval prolongation Details Ondansetron Moxifloxacin Injection Avelox Increased risk of QT interval prolongation Details Ondansetron Moxifloxacin Ophthalmic Moxeza® Increased risk of QT interval prolongation Details Ondansetron Nalbuphine Injection Nubain® Increased risk of serotonin syndrome Details Ondansetron Octreotide Bynfezia An increased risk of QT interval prolongation Details Ondansetron Octreotide Injection Bynfezia An increased risk of QT interval prolongation Details Ondansetron Ofloxacin Floxin® Increased risk of QT interval prolongation Details Ondansetron Ofloxacin Ophthalmic Ocuflox Increased risk of QT interval prolongation Details Ondansetron Ofloxacin Otic Floxin® Otic Increased risk of QT interval prolongation Details Ondansetron Olodaterol Oral Inhalation Striverdi An increased risk of QT interval prolongation and an increased risk of ventricular arrhythmias Details Ondansetron Oxaliplatin Injection Eloxatin® Increased risk of QT-interval prolongation Details

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