Spironolactone and Sulfamethoxazole and trimethoprim interaction
Spironolactone and Sulfamethoxazole and trimethoprim: both prescribing labels 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 Spironolactone label · effective 2026-08-26
…drugs that can increase potassium include: ACE inhibitors angiotensin receptor blockers aldosterone blockers non-steroidal anti-inflammatory drugs (NSAIDs) heparin and low molecular weight heparin trimethoprim 7.2 Lithium Like other diuretics, spironolactone oral suspension reduces the renal clearance of lithium, thus increasing the risk of lithium toxicity.
From the Sulfamethoxazole and trimethoprim (SULFATRIM) label · effective 2026-01-05
Drug Interactions In elderly patients concurrently receiving certain diuretics, primarily thiazides, an increased incidence of thrombocytopenia with purpura has been reported.
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.