A patient taking metformin, statins, and another medication presents. The additional medication can cause all of the following EXCEPT:

Correct answer: B. Hypoglycemia

• A. INCORRECT (some drugs in this class CAN cause xerostomia). Various medications cause dry mouth through anticholinergic effects. Many drugs combined with metformin (e.g., antihypertensives, antidepressants) list xerostomia as a side effect.
• B. CORRECT — EXCEPTION. Metformin itself does not cause hypoglycemia when used as monotherapy because it does not stimulate insulin secretion — it acts by reducing hepatic gluconeogenesis and improving insulin sensitivity. Similarly, statins do not cause hypoglycemia. The combination of metformin and statins does not put a patient at risk for hypoglycemia. Hypoglycemia is a risk with sulfonylureas and insulin.
• C. INCORRECT (statins CAN cause hepatotoxicity). Statins are associated with elevated liver enzymes (typically mild and reversible) and, rarely, drug-induced hepatitis. Hepatotoxicity monitoring is recommended with long-term statin use.
• D. INCORRECT (statins CAN cause myopathy). Statin-induced myopathy, ranging from myalgia to rhabdomyolysis, is a well-recognized adverse effect. This risk increases with high-dose statins, drug interactions (e.g., CYP3A4 inhibitors), and in certain patient populations.