Long-term experience of captopril in the treatment of primary (essential) hypertension.

1 Forty-one patients with primary (essential) hypertension were treated with captopril alone or in combination with hydrochlorothiazide for 12-36 months. 2 During an initial dose-titration period mean blood pressure fell from 174/111 mm Hg to 134/88 mm Hg supine and from 170/116 mm Hg to 126/93 mm Hg standing after 3 months' treatment. 3 During long-term treatment with unchanged or reduced doses of captopril or hydrochlorothiazide, or both, blood pressure remained substantially reduced. Mean supine blood pressure at 24 months was 136/90 mm Hg and at 36 months 138/90 mm Hg. 4 In 12 patients with clearly defined low renin (essential) hypertension initial blood pressure reduction was less than in patients with normal renin hypertension after 1 month's treatment (162/102 mm Hg v 143/92 mm Hg). After 24 months of treatment, however, the treatment results were similar in the two groups. 5 Except for one case of reversible proteinuria no serious side effects were seen during treatment periods of up to three years. 6 Captopril alone or in combination with hydrochlorothiazide seems to be an effective and safe drug in the long-term treatment of primary hypertension.