Endocrine Abstracts

Background: Gliclazide has a high propensity to cause hypoglycaemia when taken by subjects who do not have diabetes.

Case Report: A 69-year-old man presented with symptoms compatible with hypoglycaemia (sweating, lethargy, faintness). He had known hypertension, chronic kidney disease 3b, and osteoarthritis, but was not on any regular medications apart from amlodipine. Initial observations showed a capillary blood glucose (CBG) of 2.4 mmol/l. He was given 200 ml of 10% glucose intravenous, however, a repeat CBG was 1.8 mmol/L and blood ketones 0.4 mmol/l. The patient had no past history of diabetes mellitus, bariatric surgery, had not been fasting and reported no use of any herbal remedies. There was no diabetes history in any household members nor medical or nursing contacts. The patient had no previous episodes of hypoglycaemia. He was admitted to further manage his hypoglycaemia. A laboratory glucose, insulin, c-peptide and sulphonylurea screen were sent. His hypoglycaemia failed to improve with oral glucose - blood glucose rose briefly to 7.4 mmol/l, before dropping to 1.6 mmol/l. He required IV 10% glucose infusion for 16 hours to maintain euglycaemia, but thereafter was euglycaemic on a normal diet. Laboratory work up showed cortisol 362nmol/l, TSH 0.39 mIU/l, FT4 16.4 pmol/l. Laboratory glucose of 1.6 mmol/l confirmed severe hypoglycaemia and c-peptide was inappropriately raised at 3,397 pmol/l (ref 366-1465 pmol/l). He was observed for 2 days and had no further hypoglycaemic episodes. His blood sulphonylurea screen later returned positive for gliclazide (Diamicron). There was no known source of this. We have contacted his community pharmacy to ensure that there had not been a medication dispensing error.

Conclusion: This case emphasises the need for vigilance when investigating atypical causes of hypoglycaemia and for timely completion of relevant blood tests within the narrow time frame of true hypoglycaemia.