Clinical Pharmacology of Epanolol. Pharmacodynamic Aspects

Epanolol has been shown in animal models to be a selective beta-adrenoceptor partial agonist with agonist activity about 20 to 25% of that of the full agonist isoprenaline. Evidence is presented in this review supporting the conclusion that epanolol has the same pharmacological properties in man and that the agonist activity at the beta-adrenoceptor is less than the activity present in pindolol, but greater than that present in acebutolol. The pharmacodynamic consequences in man of the degree of agonist activity possessed by the beta 1-selective partial agonist epanolol include little reductions at rest in heart rate, blood pressure, various measures of cardiac haemodynamic parameters, peripheral blood flow and renal function. On exercise there is attenuation of the heart rate and systolic blood pressure responses, with less perceived exertion than with atenolol. Evidence is available which shows that attenuation of the tachycardia of exercise persists for 24 hours after a single dose of epanolol 200mg, a dose which retains selectivity for the beta 1-adrenoceptor. This pharmacological profile of epanolol in man suggests that it would be an effective antianginal agent when 200mg once daily is administered. Moreover, its unique profile (compared with other antianginal agents) may make it more tolerable to patients than existing antianginal therapy.