MajorAntiepileptics. Carboxamide derivatives×Class III antiarrhythmic
Updated · Methodology
Mechanism
Carbamazepine is a strong CYP3A4 inducer, and dronedarone is cleared through this enzyme. The labels give no data for this pair; with another strong inducer, rifampicin, dronedarone levels fell by 80% and the antiarrhythmic effect weakens. The EU SmPC of dronedarone does not recommend strong CYP3A4 inducers and names carbamazepine; the FDA label says to avoid them. No label lists the pair as a contraindication.
Symptoms
First, recurrence of atrial fibrillation symptoms: palpitations, irregular pulse, fatigue, dyspnoea. Possible rhythm breakthroughs requiring admission.
Management
Avoid the combination. If long-term anticonvulsant therapy is needed, consider a drug without CYP3A4 induction, such as levetiracetam or lamotrigine, or another rhythm control strategy, including catheter ablation. While the pair continues, watch for recurrence of atrial fibrillation: pulse, ECG, palpitations and irregular heartbeat.
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: Multaq (dronedarone) prescribing information (2025)– FDA, DailyMed setid 7fa41601-7fb5-4155-8e50-2ae903f0d2d6 (Sanofi-Aventis U.S.), version 37, revised 05/2025, sections 4, 5.8 and 7.1
- EMA: Multaq (dronedarona) – ficha técnica en CIMA (2026)– AEMPS CIMA, Multaq 400 mg comprimidos recubiertos con película, nº registro 09591003 (EU/1/09/591), secciones 4.3, 4.4 y 4.5