Safety profile of nicorandil--prescription-event monitoring (PEM) study

A PEM study of nicorandil (Ikorel) was undertaken to assess the drug's overall safety in everyday clinical practice.

The prescription data used covered the period December 1994 to October 1996. The event data, which were based on a minimum observation period of 6 months, came from questionnaires returned by the prescribing general practitioners. Incidence densities (IDs) were calculated for all events occurring during month 1, months 2-6, and the overall treatment period. Selected events were followed up.

The study was based on a cohort of 13,260 patients and 86,760 patient-months of nicorandil treatment. Major indications for use were angina (8744) and ischaemic heart disease (846). Adverse reactions (258) were reported in 175 (1.3%) of patients--the most frequent being headache (58; 0.4%) and unspecified side effects (36; 0.3%). The most common reasons for stopping treatment (excluding those confounded by indication) were headache (477; 3.5%), dizziness (88; 0.65%) and 'not effective' (491; 3.6%). The number of patients still being prescribed nicorandil after 6 months was 74.3%. In those cases where an opinion on effectiveness was given, nicorandil was reported to be effective in 80% (8713) of patients. The event of headache/migraine had the highest ID in the first month of treatment (49.4 per 1000 patient-months) and was not confounded by indication. Follow-up of selected events was reassuring overall; rare side effects included angioneurotic oedema and photosensitivity (3 cases each).

This PEM study provides information on the 'real-world' use of nicorandil and shows generally that the drug is safe when used in the recommended dosage.