Is a different effect on sympathetic nerve activity between nisoldipine and cilnidipine in humans?

Abstract

The aim of this study was to investigate whether the different effect on sympathetic activity between nisoldipine, long-acting L-type calcium channel blocker, and cilnidipine, L- and N-type calcium channel blocker, using an identical group of healthy subjects. Eight healthy men (22 to 28 years) were given 10mg nisoldipine or 10mg cilnidipine in a randomized crossover design. In each trial, without medication on day 1 (control) and with medication on day 2, subjects were measured heart rate(HR), high frequency(HF)/low frequency(LF) of HR variability and plasma noradrenaline(NA) during head-up tilt test and palmer sweating during mental arithmetic test before and 1,2,4,6, and 8 h after administration time. Plasma concentration profiles were similar between both drugs. Two-occasional controls showed no significant difference in these parameters. Head-up tilt increased HR, LF/HF and plasma NA. There were no significant difference in HR and plasma NA in supine and head-up positions at any measured times between both drugs. LF/HF (3.3±1.1) in head-up position at 4 h during cilnidipine was significantly lower than that (6.2±1.6) during nisoldipine (p=0.012). None caused postural hypotension. While there was no difference in mental arithmetic induced sweating secretion between both drugs. Cilnidipine might have a weak inhibitory effect on reflex sympathetic activity induced by head-up tilt compared to nisoldipine. Clinical Pharmacology & Therapeutics (2004) 75, P6–P6; doi: 10.1016/j.clpt.2003.11.020