Sulphonylureas are sulphonamide derivatives which lower the blood sugar when they are given by mouth by enhancing the production of INSULIN. They are e?ective in treating DIABETES MELLITUS only when some residual pancreatic beta-cell function is present. All may lead to HYPOGLYCAEMIA if given in overdose and this is particularly common when long-acting sulphonylureas are given to elderly patients. There is no evidence for any di?erence in the e?ectiveness of the various sulphonylureas. TOLBUTAMIDE was the ?rst of the sulphonlyurea drugs; it has a short duration of action and is usually given twice daily. CHLORPROPAMIDE has a more prolonged action and only needs to be given once daily, but its prolonged action causes more side-effects – including sensitivity reactions. Other oral hypoglycaemic agents of this family include glibenclamide, which has a duration of action intermediate between tolbutamide and chlorpropamide and also produces side-effects (in about 30 per cent of outpatients, according to a recent study). Other sulphonlyureas include acetohexamide, glibornuride, gliclazide, glipizide, gliquidone and tolazamide. Glymidine is a related compound with a similar action to the sulphonylureas. It is particularly useful in patients who are hypersensitive to sulphonylureas.
Sulphonylureas are best avoided in patients who are overweight, as they tend to stimulate the appetite and aggravate obesity. They should be used with caution in patients with hepatic or renal disease. Side-effects are infrequent and usually not severe, the most common being epigastric discomfort with occasional nausea, vomiting and anorexia. In about 10 per cent of patients, chlorpropamide and tolbutamide may cause facial ?ushing after drinking alcohol. Some patients are hypersensitive to oral hypoglycaemic agents and develop rashes which may progress to ERYTHEMA multi-forme and exfoliative DERMATITIS. These reactions usually appear in the ?rst 6–8 weeks of treatment.... sulphonylureas
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