Dronedarone (Multaq): Atrial Fibrillation, Safety and Interactions

A specialist treatment for selected atrial fibrillation

Dronedarone is an oral antiarrhythmic medicine available as Multaq tablets. The reviewed UK indication is maintenance of sinus rhythm after successful cardioversion in clinically stable adults with paroxysmal or persistent atrial fibrillation, after alternatives have been considered. The US indication is reduction of atrial-fibrillation hospitalisation in patients in sinus rhythm with a history of paroxysmal or persistent atrial fibrillation.

Permanent atrial fibrillation is a major safety boundary. The US boxed warning identifies increased risks of death, stroke and heart failure in relevant high-risk populations. The UK label additionally excludes people with current or previous heart failure or left ventricular systolic dysfunction. Eligibility therefore requires the actual local label and specialist assessment, not an assumption that all heart-failure states are interchangeable.

Monitoring and warning signs

Electrocardiograms, heart rhythm and relevant laboratory tests are part of follow-up. Slow heartbeat, diarrhoea, nausea, abdominal discomfort, fatigue and skin reactions can occur.

New or worsening breathlessness, swelling or rapid weight gain can suggest heart failure and require prompt assessment. Yellowing of the skin or eyes, dark urine or significant abdominal symptoms may indicate liver injury. Persistent dry cough or breathlessness also needs review because lung toxicity has been reported. Pregnancy must be discussed before treatment because of potential fetal harm.

Interaction risks are central to safe use

Strong CYP3A inhibitors, including some azole antifungals, clarithromycin and ritonavir, can markedly increase dronedarone exposure and are contraindicated in the cited labels. Other rhythm medicines and medicines that can cause torsades de pointes may also be contraindicated. Grapefruit juice should be avoided. Strong enzyme inducers, including rifampicin, carbamazepine and St John's wort, may reduce effectiveness.

Digoxin, beta blockers, some calcium-channel blockers, statins and anticoagulants need individual review. The UK label prohibits combination with dabigatran; US instructions differ according to kidney function. A pharmacist or cardiologist should resolve these product-specific differences rather than applying an online dose change or switching schedule.

Sources

• MULTAQ 400 mg tablets — UK SmPC — UK text revised 18 December 2024
• MULTAQ oral tablets — Sanofi US prescribing information — US prescribing information revised May 2025

Sources checked on 30 October 2026. This date records a source check, not a clinical review by a doctor or pharmacist. Follow the leaflet supplied with your product and consult a qualified healthcare professional about personal treatment.