Abstract: Objective To study the safety of diazoxide in the treatment of congenital hyperinsulinemia in infants. Methods A one-month-old baby with congenital hyperinsulinemia and brain injury treated with diazoxide was observed. The decrease in the urine volume and edema of both ankles as well as the increase in blood lactic acid were recorded. Diuretics were given to the patient to mitigate the edema of ankle joints and blood lactic acid was monitored dynamically. Results After discharge, the patient was followed up for 4 months by the outpatient department, during which time no ankle edema or water and sodium retention occurred, and blood lactic acid never exceeded 4.0 mmol·L^-1 after regular review. After the discontinuation of diazepine treatment, the blood glucose of the patient remained stable, and blood lactic acid returned to 2.0 mmol·L^-1. Conclusion It is recommended that thiazide diuretics be used to prevent water and sodium retention while monitoring blood lactic acid when diazoxide is used. In case of the increase of blood lactic acid, dynamic and timely monitoring is recommended so as to adjust the dose as required. However, for children with a severe lactic acid increase accompanied by blood gas abnormality and metabolic acidosis, the treatment with diazoxide should be suspended.

Key words: hyperinsulinemia, diazoxide, ADR, sodium retention, lactic acid increase