Some of the views expressed in the following notes on newly approved products should be regarded as preliminary, as there may have been limited published data at the time of publication, and little experience in Australia of their safety or efficacy. However, the Editorial Executive Committee believes that comments made in good faith at an early stage may still be of value. Before new drugs are prescribed, the Committee believes it is important that more detailed information is obtained from the manufacturer's approved product information, a drug information centre or some other appropriate source.

Ikorel (Rhone Poulenc Rorer)
10 mg and 20 mg tablets
Approved indication: angina pectoris
AMH Section 6.2

Nicorandil is a new type of vasodilator. However, it has been marketed in Japan for over a decade. The drug is a nitrate derivative, so it relaxes vascular, particularly venous, smooth muscle. It also opens the muscle's potassium channels which leads to arterial dilatation. The haemodynamic effects include reductions in end diastolic pressure and systemic resistance.

Patients with chronic stable angina can take nicorandil twice a day. The drug is rapidly absorbed with a bioavailability of 75%. Most of the drug is rapidly eliminated from plasma, but the plasma concentration is not closely linked to the effect of nicorandil. Most of the drug is metabolised and the metabolites are mainly excreted in the urine.

The most common adverse effect of nicorandil is headache. This caused up to10% of patients to stop treatment in some clinical studies. However, the headache tends to improve as treatment continues. Other adverse effects include nausea, vomiting, dizziness and flushing.

Nicorandil is probably as effective as other drugs used in the treatment of angina. Although the studies have been relatively short, the tolerance seen with nitrates does not appear to be a problem. Until more experience is obtained, nicorandil is unlikely to be used as a first-line treatment. It may have a role in patients with angina who do not respond to conventional treatment. Although there are no reported interactions with beta blockers or calcium channel blockers, there are few data on the use of nicorandil in a combined regimen.