An evaluation of debrisoquine and mefruside in the treatment of hypertension in African and Indian patients.

A double-blind, crossover trial was carried out in 20 hypertensive patients (9 African and 11 Indian) to compare the effectiveness and tolerance of treatment with debrisoquin, mefruside, and a fixed-dose combination of the two drugs with placebo. Patients were treated initially with placebo for 2 weeks before being crossed-over to treatment for 4 weeks with each of the other regimens. Maximum daily dosages of the active drugs were 20 mg debrisoquin and 25 mg mefruside. Satisfactory hypotensive control, i.e. diastolic blood pressure less than or equal to 90 mmHg, was not achieved in any of the treatment periods. The best hypotensive response was obtained in African patients on mefruside. The combination of debrisoquin and mefruside did not produce the expected synergistic response. Few side-effects were reported. The failure of an adequate hypotensive response to debrisoquin in African and Indian patients could be due to a genetic difference in the hydroxylation of debrisoquin.