Antihypertensive efficacy and tolerance of penbutolol: results of a co-operative study in 227 patients.

Abstract

An open, co-operative study was carried out in 227 patients with mild to severe essential hypertension to assess the efficacy and tolerance of penbutolol, given as monotherapy, in controlling blood pressure. Patients received a single daily dose (40 mg in the majority) for 8 weeks and were assessed every 2 weeks. The results showed that there was a significant reduction (p less than 0.01) in systolic, diastolic and mean arterial blood pressure and in pulse rate after 2 weeks compared with pre-treatment values, and there was a further significant reduction (p less than 0.01) comparing 8-week values with those measured after 2 weeks. Response to treatment did not differ significantly between those patients who were newly diagnosed and those who had received previous antihypertensive medication. The largest percentage reduction in blood pressure from initial values was recorded in those patients with the more severe hypertension (diastolic 116 to 130 mmHg) and a considerable number of all the patients became normotensive during the trial period. Records of side-effects indicated a global incidence of 17.6%, the most frequently reported being dizziness and mild gastro-intestinal disorders; only 1 patient complained of bradycardia and another of cold extremities. Eighteen (7.9%) patients dropped out of the study due to side-effects.