Which medication could most easily lead to a hypoglycemic episode during a dental appointment?

Correct answer: D. Insulin injection

• A. HCTZ is a diuretic used for hypertension — it can actually raise blood glucose slightly but does not cause hypoglycemia.
• B. Lisinopril is an ACE inhibitor — it does not affect blood glucose.
• C. Metformin works by reducing hepatic glucose production and improving insulin sensitivity — it rarely causes hypoglycemia when used alone because it does not stimulate insulin secretion.
• D. Correct. Insulin injection directly lowers blood glucose by facilitating cellular glucose uptake. An excess dose, delayed meal, or increased activity can cause hypoglycemia. Insulin is the medication most likely to cause a hypoglycemic episode in the dental chair.