Penbutolol in Hypertension: A Pilot Study with Single Daily Doses

Abstract
A pilot single-blind placebo controlled crossover within-patient study was undertaken in essential hypertension. In ten patients single daily doses of 25 mg and 50 mg and in two patients 25 mg, 50 mg and 100 mg were used. Satisfactory reductions in both systolic and diastolic blood pressure in the supine and erect postures were observed. Reduction in heart rate was of the order of 6·32%, there being no correlation between reductions in blood pressure and decrements in heart rate. Three patients were dropped from the final analyses. Seventy-eight per cent (7/9) of patients had a final diastolic pressure (lying) of 90 mm Hg or less. Single doses of penbutolol controlled blood pressure for at least twenty-four hours. At the end of two weeks on placebo medication, following nine weeks of active drug medication, blood pressure had reverted to near pre-treatment levels. Penbutolol was well tolerated.