EFFECTS OF ISRADIPINE SUSTAINED-RELEASE ON PLATELET-FUNCTION AND FIBRINOLYSIS IN ESSENTIAL HYPERTENSIVES WITH OR WITHOUT OTHER RISK-FACTORS

The aim of this study was to assess the chronic effects of a highly se lective dihydropiridine calcium channel blocker, israpidine, in its su stained release form (I-SRO), on platelet functions and fibrinolytic p arameters in subjects with essential hypertension (EH) combined or not with other well-known cardiovascular risk factors, such as cigarette smoking (EH+S) and type II diabetes mellitus (EH+DM). Thirty-six patie nts with essential hypertension with sitting diastolic blood pressures of 96-104 mmHg without (EH, n = 12) or with other risk factors (EH+S, n = 12, EH+DM, n = 12) were enrolled. After a 4-week, single-blind, p lacebo run-in period, the subjects received I-SRO 5 mg once daily for 18 weeks. After both placebo and 6 and 18 weeks of I-SRO treatment, th e following parameters were measured: sitting blood pressure by mercur y sphygmomanometer; platelet aggregation, plasma beta-thromboglobulin (BTG), platelet factor-4 (PF4), and plasminogen activator inhibitor 1 (PAI-1) by means of ELISA methods; and euglobulin lysis time before (E LT) and after standardized (10 min) venous occlusion (ELT-VO). In the group of patients as a whole compared with placebo, I-SRO significantl y reduced SBP/DBP platelet aggregation, BTG, PF4, ELT, and ELT-VO. Sig nificant reductions in these parameters were also observed in each gro up. In addition to the antihypertensive effect, I-SRO chronic treatmen t may favorably affect the platelet function and fibrinolytic system i n essential hypertension with or without other cardiovascular risk fac tors.