A comparison of the efficacy of sotalol and nadolol in the suppression of ventricular ectopic beats
The anti-arrhythmic efficacy of sotalol, aβ-blocking agent which possesses class III anti-arrhythmic properties, was compared with that of nadolol. Nadolol, .like sotalol. is non-cardioselective, is water-soluble, has no first-pass effect, is excreted unchanged in the urine, has a comparatively long half-life requiring only once-daily dosage. and has ncr intrinsic sympathomimetic activity and no membrane-stabilizing action. Twenty-two patients with stable chronic ventricular arrhythmias after myocardial infarction were studied; to qualify for entry they had to exhibit a minimum frequency of 30 ventricular ectopic beats per hour over a 24-hour Holtef monitoring period. The study was of singleblind. cross-over format with placebo periods before active drug administration and during the crossover periods. Nadolol 80 and 160 mg and sotalol160 and 320 mg were administered for 7-day periods. Routine laboratory tests were performed and serum drug concentrations measured at regular intervals. Both drugs at all dosages suppressed ventricular ectopic beats significantly (P < 0,001). No statistically significant prolongation of the QTc interval could be demonstrated with either drug. Sideeffects were negligible.