The effect of epanolol on intra-arterial ambulatory blood pressure and baroreceptor heart rate reflex in essential hypertension.

1. The effect of chronic treatment with epanolol, a new cardioselective beta-adrenoreceptor antagonist with moderate beta 1-selective intrinsic sympathomimetic activity (ISA), on 24 h ambulatory intra-arterial blood pressure (24 h IABP) and the sino-aortic baroreceptor heart rate (SAB/HR) reflex was investigated in six hypertensive subjects. 2. All subjects demonstrated a greater than 10% reduction in mean arterial pressure with atenolol therapy (100 mg once daily) before entering a randomized, double-blind, placebo-controlled, crossover protocol with epanolol (100 mg twice daily for 4 weeks). 3. Epanolol treatment at this dose was not associated with significant reduction in systolic or diastolic 24 h IABP or heart rate. There was no change in SAB/HR reflex set point, sensitivity or latency with epanolol. 4. beta 1-selective ISA may be undesirable in beta-adrenoceptor antagonists used to treat hypertension.