Comparative efficacy and safety of immediate-release and controlled-release hydralazine in black hypertensive...

Twenty-nine black hypertensive patients were randomized to treatment with controlled-release hydralazine capsules administered BID or QD, or immediate-release hydralazine tablets administered TID, for at least four weeks in a double-blind, parallel study. Hydralazine was begun after a two-week to four-week period in which blood pressure was not adequately controlled with diuretics alone. Each patient initially received 75 mg/day of the assigned drug. The dosage could be increased to 150 or 300 mg/day at weekly intervals if sitting diastolic blood pressure was not adequately controlled (greater than 90 mmHg). A beta-blocker (80 mg/day of nadolol) was added only for patients who had beta-blocker-responsive adverse effects that could not be controlled otherwise. Nine patients were considered unevaluable because of protocol violations or withdrawal from the study before completion of four weeks of treatment, primarily because of adverse effects. Twenty patients were included in the efficacy evaluation. Controlled-release hydralazine BID produced statistically significant mean falls from baseline in sitting diastolic blood pressure and in standing systolic blood pressure and an almost significant drop in standing diastolic blood pressure. Although the other two treatment groups also had substantial falls in all blood pressure measurements, the changes from baseline were not statistically significant. No significant difference in response was noted between patients who received a beta-blocker and those who did not. There were no statistically significant differences among the three treatment groups in incidence and severity of adverse effects or electrocardiographic abnormalities. A statistically, but not clinically, significant fall in hemoglobin, hematocrit, and red blood cell count was observed in all three treatment groups.