Which diabetes medication is associated with lactic acidosis risk?

• A. Acarbose
• B. Glyburide
• C. Metformin
• D. Insulin

Answer: (C)

Lactic acidosis risk is associated with metformin because, as a biguanide, it affects cellular respiration and lactate handling. Metformin can impair mitochondrial function and hepatic gluconeogenesis, leading to increased lactate production and reduced lactate clearance. The danger rises when metformin accumulates, such as in kidney dysfunction, liver disease, dehydration, sepsis, or hypoxia. In these states, a patient can develop lactic acidosis, which is why metformin use is carefully managed in renal impairment and acute illness. The other drugs listed don’t have lactic acidosis as a typical risk: acarbose mainly causes GI effects, glyburide (a sulfonylurea) can cause hypoglycemia, and insulin also risks hypoglycemia. So metformin is the medication linked to lactic acidosis.