Comparative assessment of lacidipine and nifedipine GITS: Effects on bloodpressure, platelet function, and insulin sensitivity in patients with hypertension

Objective: The aim of the present study was to assess the effects on blood pressure, platelet aggregation, and insulin sensitivity of lacidipine and n ifedipine gastrointestinal therapeutic system (GITS) given once daily in a parallel-group, double-blind, randomized study of patients with mild to mod erate hypertension. Methods: Twenty patients (12 men, 8 women) with mild to moderate hypertensi on aged 45 to 56 years (average age, 50 +/- 2.3 years) were included. They received placebo for 4 weeks and were then randomly divided into 2 groups o f 10 patients each. Nifedipine GITS 30 mg and lacidipine 4 mg were given fo r 16 weeks. Blood pressure and heart rate were measured at the clinic in th e supine, sitting, and standing positions 24 +/- 1 hours after the last dos e. At the end of the placebo and active phases the following procedures wer e performed: a platelet aggregation test; determination of platelet malondi aldehyde production; and determination of tolerance to 100 g of glucose by measuring plasma insulin. Results: Both drugs significantly reduced systolic and diastolic blood pres sures to the same level; however, observable differences in the rate of red uction were noted. In week 1, systolic blood pressure decreased 15.15% in t he nifedipine GITS group and 6.54% in the lacidipine group. Heart rate was increased slightly but significantly in the standing position in the nifedi pine GITS group only. Neither of the drugs reduced platelet aggregation ex vivo, however, both modified malondialdehyde production, indicating an effe ct at the arachidonic acid metabolic pathway. Conclusions: The effects of the drugs on the metabolism of carbohydrates we re inconclusive. However, a tendency for lacidipine to improve insulin sens itivity and for nifedipine GITS to have the opposite effect was observed.