Background Insulin overdose can result in fatal hypoglycemia. We report on a diabetic child who received an unintentional insulin overdose.

Case Report(s) A 13-year-old girl with type 1 diabetes, who was on insulin pump therapy, developed high blood glucose (BG) level due to pump malfunction. She gave herself 7 ml (700 units) instead of seven units by an error.

She presented to hospital 2 hours later when this was recognized. The initial BG in the emergency room was 13.9 mmol/l. A dextrose infusion was started 6 hours after the insulin injections when her BG dropped significantly before it reached a lowest level of 3.3 mmol/l, 9 hours after the event. It was only possible to discontinue this infusion 15 hours after insulin injections when BG was stable.

Conclusion(s) Hypoglycemia could be delayed in insulin overdose in diabetic children. This may necessitate prolonged monitoring beyond the usual half-life of insulin.