[Captopril in mild and moderate arterial hypertension resistant to diuretic therapy. A multicenter study]

To evaluate the antihypertensive effect of captopril in mild and moderate hypertensive patients uncontrolled with diuretics.

Low dose of captopril (25 to 50 mg) bid were associated during 9 weeks in 120 patients previously treated with 100 mg of hydrochlorothiazide. A subgroup of patients (74) were followed additionally for 3 weeks with the same dose of the drugs administered as a single dose. The patients were clinically evaluated after two weeks placebo, and each three weeks of active drugs. Blood pressure normalization were considered when diastolic arterial pressure was < or = 90 mmHg. Laboratory tests were measured before diuretic, before captopril and at the end of combined twelve weeks treatment.

After 15 days washout, the baseline supine arterial pressure, 168 +/- 2/ 109 +/- 1 mmHg decrease significantly with diuretic to 151 +/- 1/ 101 +/- 1 mmHg and the drop was further increased with captopril b.i.d., with a mean dose of 44 +/- 1 mg, to 137 +/- 1/ 90 +/- 1 mmHg. Blood pressure normalization was obtained in 58% patients with captopril b.i.d. and in 63% as single dose. Blood pressure normalization was achieved in 63% of non-white patients and in 56% patients over 45 years old. Plasmatic potassium decreased significantly with diuretic and did not recovered when captopril was associated.

Our results indicate that the addition of low dose of captopril twice or once a day may result in a marked additional blood pressure reduction in cases of insufficient control by the diuretic alone.