Efficacy of low-dose captopril given twice daily to patients with essential hypertension uncontrolled by a beta blocker plus thiazide diuretic.

Thirty-two patients with moderate to severe essential hypertension whose supine diastolic blood pressure (SDBP) was greater than or equal to 95 mm Hg following 2 weeks' treatment with the optimal dosage of beta blocker-diuretic combination were randomly assigned to the addition of either captopril 25 mg or 50 mg b.i.d. After 6 weeks' treatment, if patients were not normalized (SDBP less than 95 mm Hg), the dose of captopril was doubled for a further 6 weeks. The addition of captopril led to a significant fall in standing and supine diastolic and systolic blood pressure at the end of the sixth and twelfth week of treatment. There was no difference in the change in blood pressure between the two groups. At the end of the study SDBP was normalized in 66% of patients and a further 12.5% had their SDBP reduced by greater than 10%. Captopril 25 or 50 mg administered twice daily proved to be a very effective antihypertensive agent when added to a beta blocker-diuretic combination in patients resistant to optimal doses of these drugs.