[An open comparative study of captopril + hydrochlorothiazide versus chlorthalidone for the treatment of mild and moderate primary hypertension]. / Estudo aberto comparativo captopril + hidroclorotiazida versus clortalidona para tratamento da hipertensão primária leve e moderada.

ABSTRACT

PURPOSE: To compare the antihypertensive and metabolic effects of captopril combined with hydrochlorothiazide (C+HCTZ) versus chlorthalidone (CT) in mild and moderate primary hypertensive patients. METHODS: Fifty five patients, without treatment or treated with 15 days placebo were randomized for treatment with the combination of captopril 50mg and hydrochlorothiazide 25mg (n = 29) against chlorthalidone (n = 26). The clinical evaluation was done during placebo and monthly throughout three months, and the laboratory tests were done before and at the end of the study. RESULTS: The blood pressure were similar between groups during placebo period (C + HCTZ 161 +/- 25/102 +/- 6-CT 155 +/- 18/101 +/- 6 mmHg); the diastolic blood pressure decreases significantly at first month already in the group C + HCTZ (89 +/- 8 mmHg) compared to group CT (94 +/- 8 mmHg, p < 0.05). The percentile diastolic and mean blood pressure dropped, in average, 12% in C + HCTZ group and in CT varied between 7 (1st and 2nd month) to 11% (3rd month). Without statistical difference, the blood pressure normalization was obtained in 69% of the patients with the association captopril and diuretic and in 50% of the patients in the chlorthalidone group. It was observed a significant reduction of potassium in patients treated with chlorthalidone (4.2 +/- 0.7 to 3.7 +/- 0.4 mEq/L, p < 0.01) that was not observed with the captopril and the thiazide associated. The last treatment also significantly reduced the cholesterol levels (219 +/- 39 mg/dl to 202 +/- 39 mg/dl, p < 0.04). CONCLUSION: Our results indicate that captopril combined with low diuretic dose normalize the blood pressure in 69% mild to moderate primary hypertensive patients, and acts faster than chlorthalidone in this control. In addition has metabolic benefits reducing cholesterol levels with no alteration in potassium levels.