[Aphthae or painful ulcers induced by nicorandil]

A RECOGNIZED CAUSE OF BUCCAL APHTHOSIS: Nicorandil is the leading drug in a new pharmacology class of well tolerated anti-angina products with vasodilating action. The first cases of buccal aphthosis or ulcerations induced by nicorandil were reported in 1996. Among drugs inducing buccal aphthosis or ulcerations, the largest body of information available on reported cases concern nicorandil. CHARACTERISTIC LESIONS: Forty cases of painful buccal lesions induced by nicorandil have been recorded. Among the 8 publications in the literature, 7 were reported by French groups. The prevalence of this adverse effect is an estimated 5%. Patient age varies from 60 to 90 years with an even gender distribution. A history of aphthosis is noted in 23% of the cases. The lesions vary in size from 0.5 cm to 3 cm and in number from 1 to 10, generally localized on the inner aspect of the cheeks or on the tongue. The lesions develop for about 3 to 36 before diagnosis and the delay to onset of signs after initiating nicorandil treatment is 15 days to 24 months (generally 2 months). Lesions basically develop after high-dose treatments and, for a few cases, after increasing the dosage. Cure is obtained in all cases after 1 to 12 weeks.

The probability that nicorandil is the cause of these ulcerations or aphthae is very high. Certain terms do however need to be defined with precision. Are we talking about aphthae or ulcerations? The term painful ulceration would appear to be preferable because it includes both ulcerations and aphthae in cases lacking further information. The wide variability in the geographical distribution could likely be linked to underreporting. The notion of a dose effect suggests a toxic mechanism that could develop in predisposed populations (ethnic origin...) and would be directed against buccal targets (salivary glands...) via the active drug or its metabolites or via drug interactions. This new adverse effect of nicorandil is quite spectacular and very painful. However, no life-threatening event has been observed.