Nicorandil

This is a nitrate derivative of nicotinamide and is used in the treatment of angina pectoris.

• this drug, like other nitrates, causes relaxation of vascular smooth muscle (especially of the veins) resulting in a reduced ventricular filling pressure and myocardial workload.
• also nicorandil increases the efflux of potassium ions from channels in vascular smooth muscle resulting in hyperpolarisation of the cell membrane, and inhibition of calcium entry into the cell. This latter effect causes dilatation of the arteries and arterioles and is similar to the effect of calcium channel blockers.
• nicorandil can be used in patients with hypertension, diabetes mellitus, heart failure (in the absence of pulmonary oedema), chronic obstructive airways disease and cardiac conduction disorders.
• nicorandil can be combined safely with nitrates, calcium antagonists or nitrates but an additive antianginal effects has yet to be demonstrated.
• it has been proposed that nicorandil has specific 'cardioprotective properties' but these need to be confirmed by further clinical investigation
• there is evidence that, in patients with stable angina and additional risk factors (left ventricular ejection fraction <=45%, echocardiographical end-diastolic dimension > 55mm, type 1 or type 2 diabetes) that nicorandil was more effective than placebo for reducing coronary events (2). The incidence of the composite endpoint of CHD death, non-fatal MI, or unplanned admission for chest pain was lower in the nicorandil group than in the placebo group. The groups did not differ for the incidence of a composite endpoint of CHD death or non-fatal MI
  • however NICE have stated that nicorandil is not recommended to reduce cardiovascular risk in patients after an MI (3)
  • a Drug and Therapeutics Bulletin review concluded with respect to nicorandil (4) that '...it was no more effective..than standard preparations of other anti-anginal drugs. Also, there is no convincing evidence to support the use of nicorandil to improve symptom control or prevent coronary events in patients with stable angina who are taking optimal anti-anginal and secondary prevention therapy (including aspirin and a beta-blocker, with appropriate management of known risk factors for cardiovascular events, such as smoking, diabetes mellitus, blood pressure, and lipids).'

Reference:

1. Prescribers' Journal (1999), 39 (1), 39-43.
2. The IONA study Group (2002). Effect of nicorandil on coronary events in patients with stable angina: the Impact of Nicorandil in Angina (IONA) randomised trial. Lancet, 359, 1269-75.
3. NICE (May 2007). Secondary prevention in primary and secondary care for patients following a myocardial infarction
4. Drug and Therapeutics Bulletin (2003), 41 (11), 86-8.