Hemodynamic effects of nicorandil compared to isosorbitol-5-mononitrate in patients with coronary heart disease

Nicorandil is a potassium-channel opener in the therapy of coronary heart disease. In addition to a nitrate-like effect, hyperpolarisation of the cell membrane by opening of potassium channels leads to relaxation of vascular smooth muscles. In a randomized, double-blind study in 30 patients with angiographically proven coronary heart disease, efficacy of nicorandil (group 1) was compared to isosorbitol-5-mononitrate (ISMN, group 2). Hemodynamics in rest and during exercise were measured on the first day of treatment and in a subchronic phase (12 ± 4 days), each time immediately before and two hours after application. Results: Main hemodynamic variables, i.e. diastolic pulmonary arterial pressure and mean pulmonary capillary pressure were decreased significantly in both groups on the first day; there was no significant difference between both substances. In both groups, a small, not significant decrease of systolic and diastolic blood pressure was observed, heart rate and cardiac index were not significantly changed. In subchronic phase, these results were confirmed. Conclusion: Nicorandil is a new substance for the treatment of coronary heart disease with favourable hemodynamic effects comparable to nitrates. As it possesses a dual mechanism of drug action and lacking evidence for the development of a drug-tolerance, nicorandil may demonstrate advantages compared to nitrates.