Hypoglycemic coma in an elderly adult switched from twice-daily vildagliptin to once-daily glimepiride to improve drug adherence

Background: Elderly adults with diabetes are at increased risk of severe hypoglycemia and hypoglycemic coma due to various conditions including decline in cognitive function, reduced activity of daily living (ADL) and reduced renal function; special cautions are, therefore, recommended to avoid these life-threatening events. Case presentation: A 92-year-old female was admitted to our institution because of severe coma. Upon arrival, her serum C-peptide was 1.64 ng/mL despite low plasma glucose (24 mg/dL) and serum glimepiride (40.85 ng/mL). She had past history of compression fracture of her lumbar spine, which substantially affected her ADL. Her score on the dementia assessment sheet for community-based integrated care system-8 items (DASC-8) was 26 points. She had been receiving 12 oral medications for diabetes, essential hypertension, chronic gastritis and constipation from her nearby clinic. Her physician-in-charge had found that she was not taking her medications properly and simplified her prescription regimen to 3 oral medications with vildagliptin 50 mg twice daily replaced by glimepiride 3 mg once daily and asked her son to assist in taking the drugs 6 days before her admission to our hospital. While her consciousness level was improved to some extent, she was transferred to a long-term care bed hospital because it had become too difficult to care for her at home. Conclusions: It is important to note that anti-diabetes drugs should be carefully selected based on each patient’s cognitive function and ADL, and that the reasoning should be shared with the general practitioners involved to avoid severe hypoglycemic events.