Antihypertensive activity of a fixed combination of oxprenolol and chlorthalidone in mild to moderate arterial hypertension.

In a multicentre double-blind study, 92 out-patients with mild to moderate hypertension who had a resting blood pressure greater than or equal to 160/100 mmHg after a two-weeks' placebo wash-out were treated for 6 weeks with a fixed combination of oxprenolol 80 mg + chlorthalidone 10 mg per tablet or chlorthalidone alone (1 tablet = 10 mg). Five patients were drop-outs, 19 out of 44 patients on fixed combination and 7 out of 43 on chlorthalidone were given only 1 tablet b.i.d. throughout the study; the remaining doubled the corresponding dosage after the first 2 weeks. Resting and standing systolic and diastolic blood pressure decreased on both treatments, the reductions being significantly more marked on fixed combination in comparison to chlorthalidone alone (p < 0.01 and p < 0.05). The systolic blood pressure decrease was significantly greater on fixed combination from the first week of treatment (p < 0.05). Normalization of diastolic blood pressure was reached more frequently on fixed combination (73%) than on chlorthalidone (49%) (p < 0.05). Side-effects were recorded in 14 out of 44 patients treated with fixed combination and in 14 out of 43 treated with chlorthalidone. The advantages of treating patients with mild to moderate hypertension with a fixed combination of beta-blocker and diuretics are discussed.