Hypotensive effect of oxprenolol in mild to moderate hypertension: a multicentre controlled study

In a multicentre, double-blind, between-patient study the hypotensive effect of oxprenolol was investigated in 329 patients with mild to moderate hypertension. A factorial experimental design with three factors was chosen: oxprenolol--none or daily doses of 20, 40, 60 and 80 mg; dihydralazine and hydrochlorothiazide, respectively, none or 30 mg daily. Each treatment was given for 4 weeks after an adequate period of withdrawal from any other possible hypotensive therapy and one week of placebo wash-out. Irresponsive of the association with dihydralazine and/or hydrochlorothiazide, oxprenolol had a hypotensive effect linearly related to dose for standing systolic (P less than 0.05) and diastolic (P less than 0.01) pressure, and for lying diastolic (P less than 0.05) pressure. The additional of dihydralazine enhanced the time-course of the hypotensive effect of oxprenolol, particularly the 80 mg dose level. In general, the combination of oxprenolol with dihydralazine and hydrochlorothiazide caused larger reductions in blood pressure, particularly with oxprenolol 80 mg. In the latter group, the eventual falls in blood pressure were 30.5 and 14.4 mmHg for lying systolic and diastolic, respectively; and 32.1 and 20.0 mmHg for the standing systolic and diastolic pressures. The drug was well tolerated; major side effects (heart failure and bronchospasm) occurred in three patients.