Does Trimethoprim Interact with Dofetilide?
CDI records a contraindicated classification for Trimethoprim and Dofetilide. The stored summary is: Trimethoprim 160 mg BID increases dofetilide AUC by 103% and Cmax by 93%. Concomitant use is contraindicated. The mechanism involves inhibition of dofetilide renal clearance. Patients taking both medications should consult their healthcare provider before starting, stopping, or changing the dosage of either drug. This record was extracted from drug labeling through openFDA. NIH/NLM RxNorm is used for drug identities. The summary and severity classification are CDI's processed information, not a verbatim source quotation. Product, route, and patient circumstances matter.
- Severity
- Contraindicated
- Trimethoprim Class
- Dihydrofolate Reductase Inhibitor Antibacterial
- Dofetilide Class
- Antiarrhythmic
- Management
- Do not take together
- Data Source
- U.S. FDA via OpenFDA
Recorded Mechanism
Inhibition of dofetilide renal clearance
What To Tell Your Doctor or Pharmacist
If you are taking Trimethoprim and your doctor is considering prescribing Dofetilide (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