- The long term efficacy and tolerability of nifedipine combined with propranolol was assessed in a group of hypertensive patients inadequately controlled on propranolol alone. Twenty-six subjects were initially treated with propranolol in a constant daily dose of 160-240 mg, for up to 4 weeks. Nifedipine, 30 mg/day, was added and the dose was titrated upwards to 90 mg/day to achieve normal blood pressure. In 22 patients receiving the combined therapy for 14-30 weeks, mean arterial pressure dropped from 138 +/- 3 mmHg to 102 +/- 2 mmHg. Thirteen patients experienced untoward effects, and 4 discontinued the study. In the remaining 9, side effects were mild and well tolerated. Seventeen patients were subsequently treated sequentially with propranolol alone, combined therapy and nifedipine alone, to assess the efficacy of each regimen and the additive effect of each drug. The combined regimen was found to be more effective than either drug alone. A subgroup continued either combined therapy (14) or nifedipine monotherapy (3) and was followed for up to 9 months. Blood pressure control was maintained in the majority, but 4 more patients dropped out because of side effects. We conclude that the long term use of nifedipine combined with propranolol is effective and relatively well tolerated, and may offer an alternative approach to the treatment of moderately severe hypertension.