Endocrine Abstracts

Introduction: Glargine is a recombinant human insulin analogue, used in the treatment of diabetes mellitus. Although widely used, information regarding the altered time-effect profile of glargine taken in overdose is scarce. We describe a case which highlights this phenomenon.

Case report: An 82-year-old female was found by her neighbour, 18 h after attempting suicide by injecting herself with 600 units of glargine at multiple sites. Her capillary blood glucose (CBG) was 1.5 mmol/l at the scene. On treatment with oral glucogel and i.m. glucagon it rose to 3.9 mmol/l.

She was transferred to A&E 19 h post-overdose, her CBG was 6.7 mmol/l and her serum potassium was 2.5 mmol/l. She became hypoglycaemic 3 h later with a CBG of 1 mmol/l necessitating treatment with 50 ml 50% glucose.

She was admitted to a Medical ward and was commenced on an i.v. infusion of 5% dextrose at 100 ml/h. Her CBG was monitored every hour and her electrolytes every 4 h, with rate of infusion and potassium concentration being adjusted accordingly.

Her last episode of hypoglycaemia (CBG 1.9 mmol/l) occurred 63 h post-overdose which was attributed to interruption of infusion by extravasation of her i.v. cannula. Her dextrose/potassium infusion was stopped safely after 102 h. She required a total of 14 l of i.v. 5% dextrose and 540 mmol of potassium over 4 days. Although she continued to eat and drink, she remained euglycaemic for 9 days without any anti-diabetic treatment. She was recommenced on glargine 9 days post-overdose, and was transferred for inpatient Psychiatric care.

Conclusion: This case highlights that insulin glargine taken in overdose, has a much longer duration of action than is reported on product literature. Cases should be closely monitored for hypokalaemia and hypoglycaemia and treated with intravenous infusion, of which early interruption should be avoided.