Dronedarone: a safety comparison to amiodarone

Dronedarone is an oral Class III antiarrhythmic agent which was recently approved by the US Food and Drug Administration for use in nonpermanent atrial fibrillation. Structurally similar to amiodarone, dronedarone is a benzofuran derivative but it lacks the iodine moiety attached to amiodarone. Based upon the investigational clinical trials to date, it appears that dronedarone has an established efficacy when compared to placebo along with exhibiting a minimal adverse effect profile. The efficacy of dronedarone will need to be further evaluated in comparison trials with established antiarrhythmics for atrial fibrillation. The adverse profile of dronedarone appears to be substantially safer in comparison to amiodarone, although there is still little data available. The adverse effect profile of amiodarone necessitates close and extensive monitoring. Although a risk of pulmonary toxicity was identified in animals, long term studies in humans are needed to determine the significance of this adverse effect with dronedarone. One noted effect of dronedarone is an isolated increase in serum creatinine levels, and the clinical relevance of this effect needs further evaluation. Based on supporting evidence, the use of dronedarone is contraindicated in advanced or decompensated heart failure. Some clinically significant dronedarone drug interactions have been identified. Although the potential differences between dronedarone and amiodarone have been evaluated there have been no direct comparison trials published to date. This article reviews the chemistry, antiarrhythmic effects, pharmacokinetics, efficacy, adverse effects and drug interactions of dronedarone.