Trimethoprim/sulfamethoxazole-induced hypoglycemia in a patient with acute renal failure

OBJECTIVE: To report a case of trimethoprim/sulfamethoxazole (TMP/SMV)-induced hypoglycemia in a patient with acute renal failure. DATA SOURCES: English-language references identified via a MEDLINE search from January 1966 to August 1996 and a bibliographic review of pertinent articles. DATA SYNTHESIS: Similar to sulfonylureas, sulfonamides are thought to cause hypoglycemia by increasing pancreatic secretion of insulin. To date, nine cases of TMP/SMX-induced hypoglycemia have been reported in the literature. This case represents the second report in which a patient experienced TMP/SMX-induced hypoglycemia that resolved after the dosage was adjusted for the patient's decreased renal function. This case involved a 73-year-old comatose white man initiated on high-dose TMP/SMX for nosocomial pneumonia caused by Stenotrophomonas maltophilia. After 5 days of therapy, the patient presented with severe hypoglycemia that persisted over 8 hours despite multiple intravenous bolus doses and infusions of dextrose. The patient had several risk factors that may have compounded his risk for hypoglycemia, including food deprivation and acute renal failure. After management with dextrose and dose adjustment of the patient's TMP/SMX regimen according to renal function, the hypoglycemia resolved. CONCLUSIONS: TMP/SMX may cause reversible hypoglycemia that may be prolonged (approximately 12 h), particularly in patients with risk factors for hypoglycemia. Common risk factors include compromised renal function, prolonged fasting conditions, malnutrition, rind the use of excessive doses. Patients with these risk factors should be monitored closely and, more importantly, initiated on a dosing regimen adjusted for renal impairment.