Any chronic iodine overload resulting from long term ingestion of a medication or the administration of a non-resorbable contrast medium, may result in a goitre with or without hypothyroidism, and in particular in patients with a past history of thyroid disease. By contrast, the administration of iodine is no longer indicated in the treatment of enedmic goitres since the hypothesis of an iodine deficiency in the pathogenesis of such goitres may be excluded in most countries, and in particular western countries, and the risk of the development of thyrotoxicosis in such patients is not negligeable. It would thus be desirable that iodine no longer be used in the composition of medications when its presence is not indispensalbe and where, furthermore, it may contribute to developement of an increasingly disturbing iatrogenic complication.