Multicenter case series of pediatric metformin ingestion

OBJECTIVE: There are no large studies, case series, or case reports of metf ormin ingestion in children. This study summarizes the clinical course and outcomes of metformin ingestion in children reported to the American Associ ation of Poison Control Centers-certified regional poison centers. METHODS: This was a case series of all metformin ingestions in patients <18 years of age reported to eight regional poison centers. Data collection in cluded age, gender, dose ingested, co-ingestants, symptoms, vital signs, la boratory values, length of hospital stay, and medical outcome. Entrance int o the study required at least 24 hours of follow-up. RESULTS: Fifty-five cases were collected. Ages ranged from 15 months to 17 years, with a mean (+/-SD) of 4.2 +/- 4.4 years. The dose ingested, by hist ory, ranged fro 250 mg to 16.5 g, with a mean and median of 1710 +/- 3391 a nd 500 mg, respectively. Forty-one children (76%) ingested a maximum of two tablets (<less than or equal to>1700 mg). In the children younger than six years, dosage ranged from 9 to 196 mg/kg, with a mean and median of 60 +/- 41.1 and 40 mg/kg, respectively. Thirty-seven children were evaluated in a healthcare facility. Clinical effects were limited to nausea (2), diarrhea (2), and dizziness (1). None of the 38 children who had serial glucose mea surements experienced hypoglycemia. Arterial blood gas and electrolyte meas urements were performed in three and 19 children, respectively. No evidence of acidosis was demonstrated. Two children had lactate concentrations meas ured and were determined to be in the normal range. Twenty-nine patients re ceived activated charcoal. Five patients received parenteral glucose and on e adolescent with a history of diabetes received insulin for hyperglycemia. CONCLUSIONS: Unintentional ingestion of less than or equal to 1700 mg of me tformin in the healthy pediatric population does not appear to pose a signi ficant health risk of hypoglycemia or detrimental outcome. In the 21 childr en who were tested for either blood glucose, electrolyte, or lactate concen trations, no evidence of lactic acidosis was seen.