Sulphonamide derivatives which lower the blood sugar when they are given by mouth, by enhancing the production of INSULIN. They are effective 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. They include TOLBUTAMIDE, glibenclamide, gliclazide, glipizide and gliquidone.

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. Some patients are hypersensitive to oral hypoglycaemic agents and develop rashes which may progress to ERYTHEMA multiforme and exfoliative DERMATITIS. These reactions usually appear in the first 6–8 weeks of treatment.