Slow-release metoprolol and nifedipine in essential hypertension: 24 hour noninvasive ambulatory blood pressure monitoring.

To assess the efficacy and tolerability of metoprolol (MET), 200 mg slow release (SR) q.d., and nifedipine (NIF), 20 mg SR b.i.d., 20 mildly to moderately hypertensive outpatients (14 men and 6 women; mean age 41.5 years, range 27-49 years) were studied. After being withdrawn from previous antihypertensive treatments, the patients were given single-blind placebo for 2 weeks and thereafter, in double-blind, randomized sequence, MET and NIF, both for 2 weeks. At the end of each period of the study, blood pressure (BP) was recorded for 24 h using a noninvasive ambulatory BP monitoring device (ICR System) with readings taken every 10 min (from 6 a.m. to 6 p.m.), 15 min (from 6 to 12 p.m.), and 20 min (from 12 p.m. to 6 a.m.). Five patients did not complete the study because of the occurrence of unwanted effects (one patient on MET and four patients on NIF). In the 15 patients who concluded the study both drugs significantly reduced (p less than 0.01), in comparison with placebo, systolic BP (SBP), mean arterial pressure (MAP), and diastolic BP (DBP) throughout the 24 h (MET: -16.9, -11.5, and -8.9 mm Hg; NIF: -12.7, -8.4, and -6.6 mm Hg, respectively). In comparison with NIF, SBP and MAP but not DBP were significantly reduced by MET (p less than 0.01 and p less than 0.05, respectively). We conclude that in our patient population MET was more effective and better tolerated than NIF. A possible explanation could be the relatively young age of the subjects we studied.