[Beta-blocking agents alone or combined with diuretics or alpha-adrenolytics in the treatment of essential arterial hypertension].

The Authors examine the antihypertensive effectiveness of the beta-adrenergic receptor blocking agents, according to their personal experience and a review of the bibliography. It is not cleared yet how these drugs reach their hypotensive effect. It is reasonable to assume however that several factors are involved: cardiac output, intravascular volume changes, plasma renin activity and peripheral resistance. Thirty patients suffering from essential hypertension not complicated by cardiac or renale failure were treated. Patients were allocated at random into one of three subsets of ten. In group A oxprenolol was given for 8 weeks and the dose was gradually increased up to 300 mgs daily. Oxprenolol was administered in combination with clortalidone in group B and with phentolamine in group C. A clinically satisfactory reduction in blood pressure was attained in no subset, despite the significant decrease of mean blood pressure. The blockade of beta-adrenergic receptors alone has proved to be less effective than the combined administration of oxprenolol and clortalidone or of oxprenolol and phentolamine. No differences were observed between the two combinations.