Dronedarone: an emerging therapy for atrial fibrillation.

Atrial fibrillation (AF) is a common arrhythmia, with a prevalence ranging from
0.1% to 9.0% at different ages, and is associated with increased cardiovascular events and
mortality. A significant increase in the prevalence of the disease is expected to occur in
the coming years as a consequence of the aging of the population and advances in the
management of coronary artery disease and heart failure. Effective rhythm control may be
difficult to obtain in a significant proportion of patients with AF. The limited efficacy and the
possible adverse effects of antiarrhythmic drugs has led researchers to focus their attention on
new molecules, in a search of compounds with antiarrhythmic efficacy and a more favourable
safety profile. Among several new drugs developed for the management of AF, dronedarone, a
benzofuran derivative that shares many of the antiarrhythmic properties of amiodarone, but
with a more favourable safety profile, seems particularly promising. The drug is noniodinated,
has less lipophilicity, reaches therapeutic concentrations over a shorter period of time and has
lower tissue accumulation. Dronedarone, similarly to amiodarone, exhibits electrophysiologic
characteristics of all 4 Vaughan Williams classes. Clinical studies have shown that dronedarone
effectively reduces ventricular rate, may prevent or delay the recurrence of AF, and
may reduce cardiovascular morbidity and mortality in patients with AF or atrial flutter.
The drug has an overall good safety profile, in particular with low pulmonary and thyroid
toxicity. An important exception is represented by patients with unstable haemodynamic
conditions, in which the use of dronedarone has been found to be associated with an
increase in mortality. Dronedarone has been recently approved for clinical use by the
Food and Drug Administration and by the European Medicines Agency. Further
results from trials and clinical use will better define the efficacy and safety profile of
dronedarone in AF compared with other antiarrhythmic drugs and its role in the management
of patients with AF.