A COMPARATIVE-STUDY OF INTRAVENOUS ISRADIPINE AND DIHYDRALAZINE IN THE TREATMENT OF SEVERE HYPERTENSION OF PREGNANCY IN BLACK PATIENTS

Objective: To compare the efficacy and safety of intravenous isradipin e with dihydralazine in severe hypertension of pregnancy in Black pati ents. Methods: In this randomized study 40 Black patients with severe hypertension of pregnancy (DBP greater than or equal to 110 mm Hg) at a tertiary referral hospital received intravenous isradipine [an initi al dose of 0.15 mu g kg(-1) min(-1) for 15 min with increments of 0.00 25 mu g kg(-1) min-l every 15 min until diastolic blood pressure (DBP) control (DBP < 95 mm Hg) was achieved, followed by a maintenance infu sion of 0.15 mu g kg(-1) min(-1) which was given for 15 min] or dihydr alazine (6.25 mg given intravenously over 10 min; the dosage was repea ted after 20 min if control was not achieved). Mean Outcome Measures: DBP < 95 mm Hg; fetal heart rate deceleration; fetal outcome. Results: Mean systolic blood pressure was reduced from 190.9 (95% CI 182.7-199 .0) mm Hg to 137.6 (131.9-143.3) mm Hg in the isradipine group and fro m 187.9 (180.0-195.7) to 142.4 (133.0-151.7) mm Hg in the dihydralazin e group. The corresponding values for DBP were 125.8 (121.9-129.6) to 87.9 (85.0-90.7) and 124.7 (120.6-128.8) to 89.3 (85.3-93.3) mm Hg, re spectively. Differences between the groups with respect to entry and m inimum blood pressure were not statistically significant. Blood pressu re control was achieved in 19 patients who received isradipine. In the dihydralazine group, 15 of the patients required the second dose of d ihydralazine; control was achieved in 16 patients, 5 after receiving 6 .25 mg dihydralazine. Maternal heart rate rose from 83.5 (78.5-88.4) t o 118.7 (108.5-128.9) beats min(-1) following isradipine and from 78.6 (72.9-84.3) to 106.1 (98.7-113.5) beats min(-1) following dihydralazi ne. Hypotension did not occur in any patient. Fetal heart rate deceler ation was noted in 2 patients receiving isradipine and in 5 patients r eceiving dihydralazine. Fetal outcome was similar in the two groups. C onclusions: These preliminary data indicate that the efficacy and safe ty of intravenous isradipine is comparable to that of dihydralazine, a nd that isradipine could be a useful agent in lowering very high blood pressure levels rapidly in patients with severe hypertension of pregn ancy.