Double-blind comparison of metoprolol, alprenolol, and oxprenolol in hypertension.

A double-blind comparison of the beta-blockers metoprolol, alprenolol and oxprenolol was carried out to evaluate their antihypertensive effect and tolerability. 105 patients with previously untreated hypertension entered the trial and 72 completed it. Side-effects were infrequent and were never the reason for drop-out. All three drugs caused a statistically significant reduction in blood-pressure at the lower of the two doses used during a dose-finding period. At the higher dose employed in this period, metoprolol caused a significantly greater reduction in diastolic blood-pressure than did alprenolol or oxprenolol. All three drugs caused a significant reduction in heart rate. During the following period, the beta-blockers were supplemented if necessary with hydrochlorothiazide. This was required less frequently in the metoprolol group than in the other two groups.