Dronedarone

Dronedarone is a relatively new anti-arrhythmic drug that can be used in paroxysmal atrial fibrillation or paroxysmal atrial flutter.  This drug has provided an alternative to Amiodarone, a popular anti-arrhythmic drug which has a number of potential long-term side-effects.

Mechanism of action

Dronedarone is thought to act on both sodium and potassium channels in the heart muscle, slowing conduction and preventing irregular heart rhythms.  It has been shown to at least double the time to recurrence of atrial fibrillation compared to placebo in one study.

Potential side-effects

Despite its demonstrated efficacy, Dronedarone should be used with caution.  Common side effects include: diarrhoea, nausea, rash and a slow heart rate. More rarely several cases of liver failure have been reported.  Hence monitoring of liver enzymes is required indefinitely when this drug is prescribed. Current guidelines recommend liver function tests before treatment, monthly tests for the first 6 months, repeat blood tests at 9 and 12 months and periodical testing thereafter.

Contraindications

Dronedarone should not be used in patients with permanent atrial fibrillation or cardiac failure.