Does Sulfamethoxazole And Trimethoprim Interact with Procainamide?
Sulfamethoxazole And Trimethoprim and Procainamide have a moderate drug interaction according to U.S. FDA drug labeling data. 8,9 Procainamide Closely monitor for clinical and ECG signs of procainamide toxicity and/or procainamide plasma concentration if available Trimethoprim increases the plasma concentrations of procainamide and its active N-acetyl metabolite (NAPA) when trimethoprim and procainamide are coadministered. The increased procainamide and NAPA plasma concentrations that resulted from the pharmacokinetic interaction with trimethoprim are associated with further prolongation of the QTc interval. 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
- Moderate
- Sulfamethoxazole And Trimethoprim Class
- Sulfonamide Antimicrobial
- Management
- Monitor for effects
- Data Source
- U.S. FDA via OpenFDA
What To Tell Your Doctor or Pharmacist
If you are taking Sulfamethoxazole And Trimethoprim and your doctor is considering prescribing Procainamide (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 whether any dosage adjustments are needed
- Never stop or change either medication without first consulting your healthcare provider