Methimazole

Name: Methimazole Drug Interactions
Creator: Dr. Brian Staiger, PharmD, BCPS

45 interactions 127 cited references

Also sold as: Felanorm Felimazole Reguzol Tapazole®

About Methimazole

Methimazole is used to treat hyperthyroidism, a condition that occurs when the thyroid gland produces too much thyroid hormone. It is also taken before thyroid surgery or radioactive iodine therapy. This medication is sometimes prescribed for other uses; ask your doctor or pharmacist for more information. Read the full Methimazole drug information page →

Medically reviewed by Dr. Brian Staiger, PharmD, BCPS · Updated Aug 10, 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: Azathioprine Mercaptopurine Bupropion Levoketoconazole Methotrexate Tegafur

7 Major 37 Moderate 1 Minor

All (45) Major (7) Moderate (37) Minor (1)

Moderate

Methimazole Tertatolol Altered metabolism of the beta-adrenergic blocker Details Methimazole Theophylline Accurbron® Altered theophylline metabolism Details Methimazole Timolol Betimol Altered metabolism of the beta-adrenergic blocker Details Methimazole Warfarin Coumadin Decreased anticoagulant effectiveness Details

Minor

Methimazole Amiodarone Nexterone Decreased T4/T3 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.