Monotherapy with which of the following antidiabetic drug can cause hypoglycemia ?
**Core Concept**
The question tests the understanding of the risk of hypoglycemia associated with monotherapy using specific antidiabetic drugs. Hypoglycemia is a critical concern in the management of diabetes mellitus, particularly when using insulin or certain oral hypoglycemic agents that can cause a rapid decrease in blood glucose levels.
**Why the Correct Answer is Right**
The correct answer is **C. Sulfonylureas**. Sulfonylureas, such as glimepiride, glipizide, and glyburide, stimulate insulin release from the pancreatic beta cells. By closing potassium channels in the beta cells, sulfonylureas lead to an influx of calcium ions, which triggers the exocytosis of insulin-containing vesicles, resulting in increased insulin secretion. This mechanism can cause hypoglycemia, especially when used as monotherapy, as the body's insulin demand is not adequately matched by the patient's glucose production.
**Why Each Wrong Option is Incorrect**
**Option A:** Metformin is a biguanide that primarily decreases hepatic glucose production and increases insulin sensitivity. It does not stimulate insulin secretion and is less likely to cause hypoglycemia.
**Option B:** Pioglitazone is a thiazolidinedione that improves insulin sensitivity by activating peroxisome proliferator-activated receptor-gamma (PPAR-γ). It does not stimulate insulin release and is not typically associated with hypoglycemia.
**Option D:** Sitagliptin is a dipeptidyl peptidase-4 (DPP-4) inhibitor that increases the levels of incretin hormones, which in turn stimulate insulin release in response to meals. However, sitagliptin does not cause hypoglycemia when used as monotherapy because it does not stimulate insulin release in the absence of meals.
**Clinical Pearl / High-Yield Fact**
When initiating or adjusting antidiabetic therapy, it is essential to consider the patient's risk of hypoglycemia, particularly when using sulfonylureas or insulin. Patients should be educated on the symptoms and management of hypoglycemia, and monitoring of blood glucose levels should be performed regularly to adjust therapy as needed.
**Correct Answer: C. Sulfonylureas**