Atenolol plus nifedipine for mild to moderate systemic hypertension after fixed doses of either agent alone

Abstract

Three therapies were used to treat 35 patients with mild to moderate systemic hypertension: (1) the cardioselective beta-adrenoceptor blocker atenolol, (2) the calcium antagonist nifedipine and (3) combination therapy for those who failed to reach the target diastolic blood pressure (BP) of less than 90 mm Hg with monotherapy. After an initial run-in placebo period, when the mean supine diastolic BP was 102 +/- 1 mm Hg (mean +/- standard error of the mean), patients were randomized (double-blind) to atenolol, 100 mg as a single daily dose or nifedipine (slow-release form), 20 mg twice daily, then to a washout dummy placebo period before crossover. Each period lasted 4 weeks. Supine, erect and exercise BP were recorded. Atenolol and nifedipine, in the same fixed doses but in combination, were given to 20 patients in whom either supine or erect diastolic BP exceeded 90 mm Hg after the period of monotherapy. Atenolol monotherapy reduced the erect diastolic BP to less than 90 mm Hg in 14 patients (40%); of the remainder, 1 patient responded only to fixed-dose nifedipine and 11 to combination therapy, yielding a total success rate of 74%. The combination gave enhanced control, as shown by a further decrease in supine and erect BP and by better control of exercise BP; these effects were achieved without an increased incidence of adverse effects. The mean reductions in supine diastolic BP were: atenolol, 9 +/- 2 mm Hg; nifedipine, 6 +/- 2 mm Hg; and combination therapy, 16 +/- 2 mm Hg (p less than 0.05 vs atenolol or nifedipine).(ABSTRACT TRUNCATED AT 250 WORDS)