Antihypertensive effect of a non-selective (propranolol) and a cardioselective (metoprolol) beta-adrenoceptor blocking agent at rest and during exercise

Abstract

1 The antihypertensive effects at rest and during physical exercise of the non-selective beta-adrenoceptor blocker propranolol and the cardioselective beta-adrenoceptor blocker metoprolol were compared in a double-blind cross-over study. 2 Eighteen patients with mild hypertension entered the trial. One patient was withdrawn from the study due to side effects on both drugs. 3 The two beta-adrenoceptor blockers were compared using doses earlier shown to have the same beta-adrenoceptor blocking potency, as measured by their effect on exercise tachycardia in healthy men. 4 Arterial blood pressure was reduced to the same extent by propranolol and metoprolol at rest as well as during submaximal work. 5 It is concluded that the antihypertensive effect of beta-adrenoceptor blockers is mainly mediated through blockade of the beta 1-adrenoceptors.