NICORANDIL A POTASSIUM CHANNEL OPENING DRUG FOR TREATMENT OF ISCHEMIC-HEART-DISEASE

Nicorandil is the first oral potassium channel activating drug to be u sed for the treatment of symptomatic coronary artery disease. It appea rs to relax vascular smooth muscle through membrane hyperpolarization via increased transmembrane potassium conductance and, like nitrates, through on increase in intracellular cyclic GMP. In addition, nicorand il, in a nitrate-like manner, dilates normal and stenotic coronary art eries and reduces both ventricular preload and afterload. In contrast to nitrates, however, nicorandil does not appear to cause tolerance wi th long-term administration, In placebo and comparison clinical trials , nicorandil has demonstrated some efficacy and safety in patients wit h both stable and vasospastic angina pectoris, and it was found to be a myocardial protective agent in animal studies. The antianginal activ ity of nicorandil, however, is relatively short lived after dosing, wh ich will necessitate the development of extended-release formulations of the drug.