Pituitary apoplexy after combined test of anterior pituitary function.

bicarbonate concentration, which indicated a non-ketoacidotic coma.We believe this to have been due to metolazone.Controversy over the use of thiazide diuretics in hypertension continues because of their adverse metabolic effects.Consequently, the use of this group of drugs for hypertension may diminish.The use of metolazone, however, may increase in refractory oedema or sodium retention (due to congestive heart failure, hepatic cirrhosis, and renal disease) as a loop diuretic has a synergistic effect when given with a thiazide.2 5Adrenergic blocking drugs have been associated with carbo- hydrate intolerance-and propranolol particularly with recurrent non-ketotic hyperosmolar diabetic coma3-but in our patient metoprolol was continued without ill effect.Fonesca and Phear found that b adrenergic blockers are not of great importance in the pathogenesis of the hyperosmolar non-ketotic state.'Few reports of disturbance of carbohydrate metabolism with metolazone exist, and the Committee on Safety of Medicines (personal communication) has only one report each of diabetes mellitus, abnormality of electrolyte concentrations, and glycosuria.Metolazone has, however, been shown to influence diabetic control adversely.4The mechanism of this adverse reaction is not known and is common to all diuretic benzothiadiazines, including some without diuretic activity such as diazoxide.It may entail both a decrease in the secretion of insulin and an extrapancreatic effect on the liver.5This case emphasises that despite its different chemical structure metolazone, like chlorthalidone, may be associated with the hyper- osmolar non-ketotic diabetic syndrome.Clinicians using this drug in refractory sodium retention should be alert to this possibility as well as that of massive natriuresis, so that early detection may prevent the development of coma with its attendant high mortality.1 Fonesca V, Phear DN.Hyperosmolar non-ketotic diabetic syndrome precipitated by treatment with diuretics.Br MedJa 1982;284:36-7.