CriticalImmunosuppressants. Calcineurin inhibitors×Class III antiarrhythmic
Updated · Methodology
Mechanism
Dronedarone is cleared mainly by CYP3A4. The FDA classes cyclosporine as a strong CYP3A inhibitor and names it in section 4 (Contraindications) of the dronedarone label. The labels give no figure for cyclosporine itself; ketoconazole raised dronedarone levels 17-fold. The effect also runs the other way: dronedarone may raise cyclosporine levels, so the EU SmPC of dronedarone asks for monitoring of the immunosuppressant.
Symptoms
QT prolongation on ECG. Clinically: dizziness, syncope, palpitations. Severe cases progress to polymorphic ventricular tachycardia (torsades de pointes) with risk of ventricular fibrillation and sudden cardiac death. Risk rises with hypokalaemia and hypomagnesaemia.
Management
The combination is not prescribed. For post-transplant atrial fibrillation, use amiodarone or rhythm control via catheter ablation. Alternative immunosuppression: tacrolimus, with attention to its own QT risk.
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Sources
- FDA: Multaq (dronedarone) prescribing information – section 4 Contraindications (2025)– Sanofi-Aventis U.S. MULTAQ (dronedarone) tablets. Prescribing information, DailyMed setid 7fa41601-7fb5-4155-8e50-2ae903f0d2d6, sections 4 and 7
- 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