A 76-year-old woman with type 2 diabetes mellitus is brought to the hospital after her family found her unresponsive in the morning. Her daughter reports that they were busy the previous day with many activities that required extensive walking. The patient ate less dinner than usual because she felt tired. She has discontinued several antidiabetic medications in the past due to medication intolerance but recently has had good glycemic control with a single medication. Blood pressure is 140/80 mm Hg and pulse is 102/min. The patient is diaphoretic and responds only to pain. Pupils are equal, round, and reactive to light. Cardiopulmonary examination is normal. Blood glucose is 34 mg/dL. The patient's condition rapidly improves after administration of an intravenous bolus of dextrose, but she becomes confused again several hours later. Repeat blood glucose is 39 mg/dL. Which of the following medications is the most likely cause of this patient's current condition?

Question

A 76-year-old woman with type 2 diabetes mellitus is brought to the hospital after her family found her unresponsive in the morning.  Her daughter reports that they were busy the previous day with many activities that required extensive walking.  The patient ate less dinner than usual because she felt tired.  She has discontinued several antidiabetic medications in the past due to medication intolerance but recently has had good glycemic control with a single medication.  Blood pressure is 140/80 mm Hg and pulse is 102/min.  The patient is diaphoretic and responds only to pain.  Pupils are equal, round, and reactive to light.  Cardiopulmonary examination is normal.  Blood glucose is 34 mg/dL.  The patient's condition rapidly improves after administration of an intravenous bolus of dextrose, but she becomes confused again several hours later.  Repeat blood glucose is 39 mg/dL.  Which of the following medications is the most likely cause of this patient's current condition?

Quizplus · Accepted Answer

11ec160b_3bb1_772b_9249_65919247aefc_MD0001_00 This patient's persistent hypoglycemia is most likely due to an excessive insulin response from her diabetes medication. Given the availabile answer options, she was most likely taking a sulfonylurea (eg, glyburide). Sulfonylurea bind to a receptor on pancreatic beta cells and inhibit the ATP-sensitive potassium channel. This alters the cell's resting potential and allows calcium influx, leading to exocytosis of insulin. The net result is increased insulin secretion independent of blood glucose concentrations, which confers a significant risk of hypoglycemia. Hypoglycemia with sulfonylureas can be induced by exercise, missed meals, acute illness, or initiation of additional antidiabetic medications. The risk is greater in the elderly and in patients with metabolic dysfunction (eg, chronic kidney disease, hepatic impairment). As in this patient, sulfonylurea-induced hypoglycemia may reoccur, even after successful initial treatment, until the drug has been cleared from the circulation. (Choice A) Acarbose is an alpha-glucosidase inhibitor that decreases intestinal glucose absorption and blunts the postprandial rise in serum glucose. Although it can increase insulin sensitivity in the elderly, acarbose is not associated with significant hypoglycemia. (Choice C) Metformin is a biguanide that decreases hepatic glucose production and intestinal glucose absorption and increases peripheral glucose uptake and utilization. Metformin has rarely been associated with lactic acidosis but does not typically cause hypoglycemia. (Choice D) Thiazolidinediones (eg, pioglitazone) increase insulin sensitivity by increasing glucose utilization and decreasing glucose production in adipose tissue, muscle, and liver. Thiazolidinediones have been associated with cardiac side effects (eg, heart failure) but carry a low risk of hypoglycemia. (Choice E) Meglitinides (eg, repaglinide) are insulin secretagogues that induce pancreatic insulin secretion even when blood glucose levels are normal. Although they can cause hypoglycemia, they have a very short half-life (~1 hr) and are less likely than sulfonylureas to cause prolonged hypoglycemia, as in this patient. (Choice F) Sitagliptin is a dipeptidyl peptidase 4 inhibitor that increases glucose-dependent insulin release from the pancreatic beta cells. Its effect on insulin release diminishes as glucose levels approach normal, and so it does not usually cause hypoglycemia. Educational objective: Sulfonylureas (eg, glyburide, glimepiride) increase insulin secretion by pancreatic beta cells independent of blood glucose concentration. These medications have a high incidence of hypoglycemia, especially in the elderly. __________ References: Minimizing hypoglycemia in diabetes. (http://www.ncbi.nlm.nih.gov/pubmed/26207052)

A 76-Year-Old Woman with Type 2 Diabetes Mellitus Is Brought