Efficacy of penbutolol + piretanide combinations in the treatment of arterial hypertension.

The efficacy and tolerability of penbutolol alone and in combination with piretanide at two dose levels were investigated in a double-blind parallel group study in patients with mild to moderate essential hypertension. All three treatments were given as a single daily dose. One hundred and eight patients entered the study; 82 completed a 7-day placebo run-in period followed by 3 weeks of active therapy. Penbutolol 20 mg plus piretanide 3 mg and penbutolol 40 mg plus piretanide 6 mg both produced a significantly greater reduction in supine diastolic blood pressure (16% and 19% respectively) than penbutolol 20 mg (9%). The reduction in supine diastolic blood pressure was significant for all three treatments with respects to the baseline reading. Side-effects were generally mild and transient and were similar in type and incidence in the three groups. Six patients did not complete the trial period because of an excessive response to the hypotensive medication: five in the high dose combination group, and one in the low dose combination group. Low doses of penbutolol (20 mg) and piretanide (3 mg) used in combination and in a once-daily administration provide a simple, effective and well tolerated regimen for patients with mild to moderate hypertension.