Critical
Dronedarone × Rifampicin
Class III antiarrhythmic×Antituberculous antibiotic
Mechanism
Rifampicin is a potent CYP3A4 inducer. Dronedarone plasma levels fall by 80% and antiarrhythmic effect is lost. FDA Multaq Section 4.3 specifically lists rifampicin.
Symptoms
Recurrence of atrial fibrillation symptoms: palpitations, irregular pulse, fatigue, dyspnoea. Possible rhythm breakthroughs requiring admission.
Management
The combination is not prescribed. For tuberculosis in a patient with atrial fibrillation, switch the antiarrhythmic to amiodarone or perform catheter ablation during anti-TB therapy. Rifampicin is hard to substitute – it remains part of standard first-line regimens.
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.