Acebutolol for premature ventricular contractions: short- and long-term effects.

The safety and efficacy of oral acebutolol therapy for the suppression of premature ventricular contractions (PVCs) were assessed in two clinical trials pooled for analysis. Thirty-two patients suffering from organic heart disease, who had experienced an average of greater than or equal to 10 PVCs/h (range 14 to 996 three times a day) on Holter monitoring during a 24-hour baseline study period, were given acebutolol (100 mg three times a day to 400 mg four times a day) over 4 weeks. Three patients were withdrawn from the study for administrative reasons, and four patients were excluded from the efficacy analysis. Of the 25 remaining patients (24 men, 1 woman; mean age 56 years, range 37 to 69), 18 (72%) experienced some reduction in PVCs from the second through the fourth week of therapy. Eleven patients (44%) experienced clinically significant reductions (greater than or equal to 75%) in PVCs. The onset of the antiarrhythmic effect of acebutolol was within 7 days of administration. Transient mild to moderate side effects were noted in eight patients. Significant correlations (p less than 0.001) were observed between the mean daily dose of acebutolol and (1) mean blood levels, (2) reduction in PVCs, and (3) reduction in resting heart rate. The average daily dose of acebutolol ranged from 304 to 1060 mg. In nine patients receiving acebutolol in a 12-month open-label extension, both efficacy and safety were maintained. This study confirms that oral acebutolol therapy in both safe and efficacious for suppressing PVCs in patients with organic heart disease.