Oxprenolol vs propranolol: a randomized, double-blind, multiclinic trial in hypertensive patients taking hydrochlorothiazide. Veterans Administration Cooperative Study Group.

Oxprenolol (O) or propranolol (P) was randomly added double-blind to the regimen of 260 patients with mild and moderate hypertension who had not responded to hydrochlorothiazide (H) alone. Both beta-adrenergic blocking agents were titrated over a range of 120 to 360 mg per day while H was continued. After 6 months of treatment, reduction of diastolic blood pressure (DBP) to below 90 mm Hg and at least 5 mm Hg less than the initial DBP was achieved in 50% of patients receiving P+H and 27% of patients taking O+H (p less than 0.001). P+H lowered BP an additional 10.5/9.8 mm Hg compared with 6.8/7.0 mm Hg for O+H (p less than 0.02). Reduction in heart rate was less after O+H (average, 8.4/min) than after P+H (average, 12.3/min, p less than 0.01). The number of dropouts, morbid events, and reported side effects between the two regimens was not significantly different except that more patients complained of impotence with P+H than with O+H (p less than 0.05).