Comparison of nifedipine (retard formulation) and mefruside in the treatment of mild to moderate hypertension--a prospective randomized double-blind crossover study in general practice.

Twenty-two patients under general practice care, suffering mild to moderate hypertension and receiving no active treatment had three baseline blood pressure measurements taken during a single blind 4-week placebo run-in period. One patient was secondarily excluded at this stage because of a placebo response and one patient dropped out for personal reasons. The remaining 20 patients were randomized to receive either nifedipine 20 mg twice a day or mefruside 25 mg once a day in a classical two-period crossover design with 8-week treatment periods separated by a 4-week single-blind placebo washout. During 8 weeks nifedipine therapy the mean supine blood pressure was reduced from 173 (s.d. = 15.4)/107(s.d. = 6.4) mmHg to 150(s.d. = 16.7)/93(s.d. = 10.8) mmHg whereas the corresponding reduction for mefruside was from 174(s.d. = 15.9)/107(s.d. = 9.4) mmHg to 153(s.d. = 19.1)/94(s.d. = 9.7) mmHg. Neither drug affected postural changes in blood pressure. Standing blood pressure measurements under 8 weeks nifedipine therapy fell from 172(s.d. = 12.3)/103(s.d. = 5.6) mmHg to 150(s.d. = 17.9)/94(s.d. = 10.0) mmHg with corresponding changes for mefruside being 174(s.d. = 14.7)/106(s.d. = 9.0) mmHg to 150(s.d. = 20.2)/95(s.d. = 9.4) mmHg. Since blood pressures returned to within 4% of baseline values by the end of the placebo washout period it can be inferred that each therapy was a significant (P less than 0.05 for all blood pressure variables) antihypertensive treatment in its own right.