Does Pyrimethamine Interact with Sulfamethoxazole And Trimethoprim?
Pyrimethamine and Sulfamethoxazole And Trimethoprim have a contraindicated drug interaction according to U.S. FDA drug labeling data. Reports suggest megaloblastic anemia risk when pyrimethamine doses exceed 25 mg weekly with concurrent sulfamethoxazole and trimethoprim use. Patients taking both medications should consult their healthcare provider before starting, stopping, or changing the dosage of either drug. This information is based on official FDA drug labeling sourced from OpenFDA and the NIH National Library of Medicine.
- Severity
- Contraindicated
- Pyrimethamine Class
- Dihydrofolate Reductase Inhibitor Antimalarial
- Sulfamethoxazole And Trimethoprim Class
- Sulfonamide Antimicrobial
- Management
- Do not take together
- Data Source
- U.S. FDA via OpenFDA
What To Tell Your Doctor or Pharmacist
If you are taking Pyrimethamine and your doctor is considering prescribing Sulfamethoxazole And Trimethoprim (or vice versa), make sure to:
- Inform your doctor and pharmacist of all current medications, including over-the-counter drugs and supplements
- Ask whether the benefits of combining these medications outweigh the risks for your specific situation
- Ask what symptoms to watch for that would indicate the interaction is causing problems
- Ask about alternative medications that do not interact with your current regimen
- Ask how frequently you should be monitored while these are co-prescribed
- Never stop or change either medication without first consulting your healthcare provider