Metolazone and Sulfamethoxazole and trimethoprim interaction

Metolazone and Sulfamethoxazole and trimethoprim: both prescribing labels describe an interaction that usually calls for monitoring, a dose change, or spacing the doses.

Moderate

Usually manageable with monitoring or a dose change. Tell your pharmacist you take both.

What the FDA labels say

From the Sulfamethoxazole and trimethoprim (SULFATRIM) label · effective 2026-01-05

Moderate

Drug Interactions In elderly patients concurrently receiving certain diuretics, primarily thiazides, an increased incidence of thrombocytopenia with purpura has been reported.

Drug interactionsby drug classView label on DailyMed

From the Metolazone label · effective 2026-01-15

Minor

Cross-Allergy Cross-allergy may occur when metolazone tablets, USP, are given to patients known to be allergic to sulfonamide-derived drugs, thiazides, or quinethazone.

Warningsby drug classView label on DailyMed

Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.

Open in the checker

Not 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.