Methimazole and Rifampin interaction
Methimazole and Rifampin: the Rifampin prescribing label describe an interaction that usually calls for monitoring, a dose change, or spacing the doses.
Usually manageable with monitoring or a dose change. Tell your pharmacist you take both.
What the FDA labels say
From the Rifampin (Rifadin IV) label · effective 2026-05-27
Substitute non-enzyme inducing therapies at least 2 weeks prior to initiation of irinotecan therapy Decrease irinotecan and active metabolite exposure Levothyroxine Decrease exposure Losartan Parent Decrease AUC by 30% Active metabolite (E3174) Decrease AUC by 40% Methadone In patients well-stabilized on methadone, concomitant administration of rifampin resulted…
Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.
Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.