Doxepin achieved ≥80% suppression of ventricular premature depolarizations in 40% of patients, but marked sedation limits its usefulness for primary treatment of arrhythmias.
Does doxepin suppress ventricular arrhythmias in cardiac patients with frequent ventricular premature depolarizations?
While doxepin can suppress ventricular premature depolarizations in some patients, its clinical utility is severely limited by marked sedation.
The effect of doxepin on ventricular arrhythmias, the ECG, and left ventricular function was evaluated in 10 cardiac patients with symptoms with frequent ventricular premature depolarizations in a dose-ranging protocol. Four patients (40%) had greater than or equal to 80% ventricular premature depolarization suppression; four of eight with pairs and four of six with ventricular tachycardia had greater than or equal to 90% suppression. The mean maximal doxepin dose was 115 +/- 41 mg/day; mean nadir total doxepin concentration was 61 +/- 48 ng/ml and mean nadir total desmethyldoxepin concentration was 51 +/- 42 ng/ml. Doxepin increased the heart rate and the PR, QRS, and QTc intervals of the surface ECG (P not significant). There was no significant change in resting mean left ventricular ejection fraction with doxepin: 41% +/- 15% vs. 43% +/- 19% (P not significant). Complaints of sedation (eight patients) limited dose ranging and tolerance to the drug. Although doxepin suppressed ventricular premature depolarizations in four patients, marked sedation limits its usefulness for primary treatment of arrhythmias in this population.
Giardina et al. (Wed,) conducted a other in Ventricular arrhythmias (n=10). Doxepin was evaluated on Greater than or equal to 80% ventricular premature depolarization suppression. Doxepin achieved ≥80% suppression of ventricular premature depolarizations in 40% of patients, but marked sedation limits its usefulness for primary treatment of arrhythmias.