CriticalClass III antiarrhythmic, selective IKr blocker×Antibacterial, dihydrofolate reductase inhibitor
Updated · Methodology
Mechanism
Trimethoprim inhibits renal OCT2 transporter clearing dofetilide. Levels double. FDA Tikosyn Section 4.3 strict contraindication.
Symptoms
Torsades de pointes.
Management
Combination contraindicated.
Check the full regimen, not just this pair
Opens the checker with these two drugs prefilled. Add the rest of the regimen and recompute additive risks.
Summary of a multi-drug list →
Medicine list: everything you take in one place →
Sources
- FDA: Tikosyn (dofetilide) prescribing information (2019)– FDA Tikosyn label, Section 4 Contraindications