Modest antihypertensive effect of epanolol, a beta 1-selective receptor blocker with beta 1 agonist activity: an acute and long-term hemodynamic study at rest and during exercise and double crossover comparison with atenolol on ambulatory blood pressure.

Beta-blockers with less cardiodepressive effect than traditional nonselective beta(1+2)-blocking agents could be useful in the treatment of hypertension, provided the reduction in blood pressure was satisfactory. Epanolol, a selective beta 1-receptor blocker with intrinsic sympathomimetic activity, induced a fall in intraarterial pressure of 8% at rest sitting and 11% during 100 W bicycle exercise after the first dose of 200 mg in 12 patients with essential hypertension. Heart rate, stroke index, and cardiac index initially fell by 14%, 11%, and 23%, respectively. The total peripheral resistance index increased by 21% after 2 hours, and then reverted towards the pretreatment level. After 10 months of epanolol treatment (mean 300 mg/day), the reduction in arterial pressure was 5% at rest and 10% during exercise. Cardiac index and heart rate were still reduced 14-21%, while total peripheral resistance was unchanged or slightly increased (2-10%). Twenty-four hour ambulatory blood pressure was higher on epanolol (300 mg/day) than on atenolol (150 mg/day) treatment (137/97 vs. 128/91 mmHg). Thus, the achieved blood pressure reduction induced by epanolol was moderate, while other characteristics of beta-receptor blockade, in particular, the reduction of heart rate and cardiac output, were maintained. This suggests that the compound may be useful for other cardiovascular disorders, e.g., angina pectoris in patients without hypertension or cardiac arrhythmia.