Trimethoprim-sulfamethoxazole-associated severe hypoglycaemia: a sulfonylurea-like effect
Nunnari, G.; Celesia, B.M.; Bellissimo, F.; Tosto, S.; La Rocca, M.; Giarratana, F.; Benanti, F.; Caltabiano, E.; Russo, R.; Cacopardo, B.
European Review for Medical and Pharmacological Sciences 14(12): 1015-1018
2010
ISSN/ISBN: 1128-3602 PMID: 21375132 Document Number: 639434
To report hypoglycaemia, a life-threatening adverse event, associated with trimethoprim-sulfamethoxazole. A sulfonylurea-like effect, leading to insulin raise, was investigated. Two cases of trimethoprim-sulfamethoxazole-associated hypoglycaemia in 2 patients with a diagnosis of new HIV-1-infection presenting with Pneumocystis jiroveci pneumonia are reported. The patients had no predisposing factors, such as renal or liver impairment, interfering with trimethoprim-sulfamethoxazole elimination, thus leading to hypoglycaemia. Insulin plasma levels were measured in both patients. Severe hypoglycaemia was associated with increased serum levels of insulin up to 84 microU/ml (normal values < 10 microU/ml). Continuous dextrose infusion was necessary, further suggesting the sulfonylurea-like effect of sulfamethoxazole. Interestingly, plasma levels of insulin progressively raised after trimethoprim-sulfamethoxazole administration. Only 18 cases of trimethoprim-sulfamethoxazole associated hypoglycaemia are reported in the literature. Hypoglycaemia is a life-threatening condition, likely underreported, to consider when trimethoprim-sulfamethoxazole administration is required, even in the absence of predisposing factors or other hypoglycaemic agents. Physician should bear in mind the potential trimethoprim-sulfamethoxazole-associated adverse event especially when prolonged treatments and elevated dosage are used.