Tamoxifen

89 interactions 5 explained in plain English

Also sold as: Nolvadex® Soltamox Soltamox®

About Tamoxifen

Tamoxifen is an antiestrogen medication used to treat breast cancer and reduce the risk of developing it in high-risk women. Read the full Tamoxifen drug information page →

Medically reviewed by Dr. Brian Staiger, PharmD, BCPS · Updated Jun 30, 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 Lefamulin Oxaliplatin Injection Dasatinib Sertraline Ofloxacin

2 Contraindicated 81 Major 6 Moderate

All (89) Contraindicated (2) Major (81) Moderate (6)

Major

Tamoxifen Fluorouracil Adrucil An increased risk of thromboembolism Details Tamoxifen Fluorouracil Injection Adrucil An increased risk of thromboembolism Details Tamoxifen Fluorouracil Topical Carac An increased risk of thromboembolism Details Tamoxifen Foscarnet Injection Foscavir Increased risk of QT interval prolongation Details Tamoxifen Fostemsavir Rukobia Increased risk of torsade de pointes Details Tamoxifen Galantamine Razadyne An increased risk of QT interval prolongation Details Tamoxifen Gatifloxacin Ophthalmic Zymar® An increased risk of QT interval prolongation Details Tamoxifen Gemifloxacin Factive An increased risk of QT interval prolongation Details Tamoxifen Glasdegib Daurismo Increased risk of QT interval prolongation Details Tamoxifen Goserelin Implant Zoladex Increased risk of QT interval prolongation Details Tamoxifen Granisetron Transdermal Patch Sancuso An increased risk of QT interval prolongation Details Tamoxifen Granisetron Injection Granisol An increased risk of QT interval prolongation Details Tamoxifen Histrelin Implant Supprelin Increased risk of QT interval prolongation Details Tamoxifen Hydroxychloroquine Plaquenil Increased risk of retinal toxicity and increased risk of QT-interval prolongation Details Tamoxifen Inotuzumab Ozogamicin Injection Besponsa Increased risk of QT interval prolongation Details Tamoxifen Ivabradine Corlanor Increased risk of QT prolongation Details Tamoxifen Lanreotide Injection Somatuline Altered exposure to CYP3A4 substrate Details Tamoxifen Lenvatinib Lenvima Increased risk of QT-interval prolongation Details Tamoxifen Letermovir Injection Prevymis Increased CYP3A substrate exposure Details Tamoxifen Levofloxacin Levaquin Increased risk of QT interval prolongation Details Tamoxifen Levofloxacin Injection Levaquin Increased risk of QT interval prolongation Details Tamoxifen Loperamide Diamode An increased risk of QT interval prolongation, which may increase risk of cardiotoxicity (torsade de pointes, cardiac arrest) Details Tamoxifen Mefloquine Lariam® An increased risk of QT interval prolongation Details Tamoxifen Mercaptopurine Purinethol® An increased risk of hepatotoxicity Details Tamoxifen Methotrexate Jylamvo An increased risk of thromboembolism, increased methotrexate exposure, an increased risk of methotrexate-related severe adverse re... Details Tamoxifen Methotrexate Injection Abitrexate® An increased risk of thromboembolism, increased methotrexate exposure, an increased risk of methotrexate-related severe adverse re... Details Tamoxifen Metronidazole Flagyl An increased risk of QT interval prolongation Details Tamoxifen Metronidazole Injection Flagyl An increased risk of QT interval prolongation Details Tamoxifen Metronidazole Topical MetroCream® An increased risk of QT interval prolongation Details Tamoxifen Metronidazole Vaginal MetroGel® Vaginal An increased risk of QT interval prolongation Details Tamoxifen Mitapivat Aqvesme Reduced CYP3A substrate exposure Details Tamoxifen Mitomycin Jelmyto Increased risk of hemolytic uremic syndrome Details Tamoxifen Mitomycin Pyelocalyceal Jelmyto Increased risk of hemolytic uremic syndrome Details Tamoxifen Moxifloxacin Avelox Increased risk of QT interval prolongation Details Tamoxifen Moxifloxacin Injection Avelox Increased risk of QT interval prolongation Details Tamoxifen Moxifloxacin Ophthalmic Moxeza® Increased risk of QT interval prolongation Details Tamoxifen Octreotide Bynfezia Increased tamoxifen exposure and an increased risk of QT interval prolongation Details Tamoxifen Octreotide Injection Bynfezia Increased tamoxifen exposure and an increased risk of QT interval prolongation Details Tamoxifen Ofloxacin Floxin® An increased risk of QT interval prolongation Details Tamoxifen Ofloxacin Ophthalmic Ocuflox An 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.