Endocrine Abstracts

Intentional insulin overdose in diabetic patients is a rare critical situation. The severity is due to numerous neurological complications, electrolyte disturbances, liver and lung damage or death.

Case report: A 65-year-old male, with significant cardiac and pulmonary pathology, diagnosed with type 2 diabetes since 1996 and treated with glargine (70 U/day) and aspart (68 U/day) insulin is admitted to our centre via ER (emergency room) after an episode of severe hypoglycaemia after administration of 750 U aspart insulin and 280 U glargine insulin. He arrived in the ER 3 h after overdose with a glycaemic value of 47 mg/dl after 40 ml of 33% glucose and 250 ml of 10% glucose. At admission: altered general status, blood glucose 105 mg/dl, tachycardia, multiple injection sites across his abdomen, acanthosis nigricans on the right elbow. Labs exams revealed: hypertrygliceridaemia, hypocalcaemia, slightly elevated creatinine, A1c=7.9%. An infusion of 20% glucose was begun at 83 ml/h. The glucose infusion rhythm and concentration was adjusted according to the glycaemic profile while maintaining values around 150 mg/dl, with a total duration of infusion of 61 h. Hypocalcaemia was corrected by i.v. administration of calcium gluconate. Electrolytes, phosphorus and magnesium remained within normal limits during hospitalization. Psychological and psychiatric evaluation diagnosed depression and emotional unstable disorder. To increase the insulin clearance i.v. Furosemide was given for 6 days. In the 5th day of hospitalization, we decided the conversion to oral therapy with metformin 2 g/day and sitagliptin 100 mg/day, with a good glycaemic control.

Discussions: Insulin overdose requires intensive and prolonged glycaemic monitoring to prevent recurrent hypoglycaemia due to an early cessation of i.v. therapy. The dose is not correlated with the severity of hypoglycaemia but with a prolonged hypoglycaemic risk higher than that deduced from the pharmacokinetics of insulin analogue administered. This case represents the largest overdose with this analogues treated only by glucose infusion.