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 selective dihydropiridine calcium channel blocker, israpidine, in its sustained release form (I-SRO), on platelet functions and fibrinolytic parameters 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 patients 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, placebo 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, the following parameters were measured: sitting blood pressure by mercury 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 (ELT) and after standardized (10 min) venous occlusion (ELT-VO). In the group of patients as a whole compared with placebo, I-SRO significantly reduced SBP/DBP platelet aggregation, BTG, PF4, ELT, and ELT-VO. Significant reductions in these parameters were also observed in each group. In addition to the antihypertensive effect, I-SRO chronic treatment may favorably affect the platelet function and fibrinolytic system in essential hypertension with or without other cardiovascular risk factors.