831 - Trimethoprim-sulfamethoxazole–induced Hypoglycemia in a Pediatric Inpatient Rehabilitation Setting

Trimethoprim-sulfamethoxazole (TMP-SMX) is an antibiotic commonly used in the rehabilitation setting for treating infections including uncomplicated urinary tract infections. It is typically well tolerated with known side effects including nausea, vomiting, loss of appetite, dizziness, and fatigue. However in rare situations, TMP-SMX may cause potentially life-threatening hypoglycemia.
We report on a pediatric patient admitted for acute inpatient rehabilitation following elective right peri-insular functional hemispherotomy for management of her KCNT1-associated refractory epilepsy. During treatment of an uncomplicated urinary tract infection with TMP-SMX, she developed refractory hypoglycemia requiring transfer to the intensive care unit for further evaluation and management.

Discussions: This case highlights the importance of recognizing rare, but serious, side effect of TMP-SMX–induced hypoglycemia. The few reported cases of hypoglycemia from TMP-SMX are mostly in the adult population with only one pediatric case reported involving a severely immunocompromised patient with primary immunodeficiency. TMP-SMX-induced hypoglycemia commonly occurs in patients with prolonged dosing of TMP-SMX, poor nutrition, and renal dysfunction which reduces drug clearance. In our patient, her increased activity, reduced intake, post-operative metabolic stress, and possible drug interactions likely contributed; however, she lacked the aforementioned significant risk factors. In the IPR setting where patients have increased activity, inconsistent intake, and multiple medications, even subtle risk factors may raise the likelihood of complications such as hypoglycemia.

Conclusions: This case underscores that TMP-SMX–induced hypoglycemia, though rare, can occur in pediatric patients without classic predisposing factors such as renal dysfunction, malnutrition, or immunodeficiency. Factors such as reduced intake, high activity from therapy, and stress from recent surgery may be sufficient to trigger this complication in the rehabilitation setting. Early recognition and discontinuation of the drug are key to resolving hypoglycemia and preventing complications.