Dronedarone

How it works

It is a multichannel blocker with class I, II, III and IV antiarrhythmic properties, prolonging the action potential and refractory period while also slowing AV nodal conduction.

Prescribing in practice

• Contraindicated in permanent atrial fibrillation and in heart failure or left ventricular systolic dysfunction, where it increases mortality, and it must be stopped if AF becomes permanent.
• It is a potent enzyme and transporter inhibitor with important interactions, including raising digoxin and increasing the bleeding risk and exposure with some anticoagulants, and is contraindicated with drugs that markedly prolong the QT interval.
• Hepatotoxicity, including rare severe liver injury, and pulmonary toxicity have been reported, so baseline and ongoing liver function checks are required.

Monitoring

Monitor ECG (including QT interval and rhythm), liver function and renal function periodically, and review for signs of heart failure or pulmonary toxicity.

Counselling the patient

• Report breathlessness, ankle swelling, weight gain or a persistent cough promptly.
• Seek urgent advice for jaundice, dark urine, severe tiredness or abdominal pain.
• Avoid grapefruit juice, which raises levels of this medicine.

Evidence & guidelines

MHRA and NICE advise dronedarone is contraindicated in heart failure and permanent AF following trial evidence of increased cardiovascular harm.