Mefloquine-associated hypoglycaemia in a cachectic AIDS patient.

Quinine and its isomer quinidine are well-known causes of iatrogenic hypoglycaemia, due to excessive insulin secretion. The situation is less clear regarding other anti-malarial quinine analogues. In particular, this adverse effect has never been described with mefloquine (Lariam). We report a case of hypoglycaemia after mefloquine therapy (1,500 mg over two days) for severe gastrointestinal cryptosporidiasis in a cachectic AIDS patient with protracted diarrhoea. Blood glucose levels, which were normal before treatment, dropped to 2.3 mmol/l within a few hours and were corrected by i.v. glucose infusion. Hypoglycaemia did not recur despite continued treatment. Rat islets of Langerhans exposed to mefloquine in vitro (10(-8) mol/l to 10(-3) mol/l) secreted significantly more insulin than control islets (up to 980 +/- 180 microU/ml/5 islets incubated with mefloquine 10(-3) mol/l, vs 20 +/- 4 microU/ml/5 untreated islets). Mechanisms and triggering factors of hypoglycaemia induced by mefloquine and some other anti-malarial quinine analogues are discussed. Clinicians who manage cachectic patients, particularly those with protracted diarrhoea and/or receiving anti-malarial drugs including mefloquine, should be aware of the risk of severe hypoglycaemia.