Which of the following anti diabetic drugs can cause vitamin B12 deficiency: (A) Glipizide, (B) Acarbose, (C) Metformin, (D) Pioglitazone
Answer is C. Refer Goodman Gilman 12/e p 1259 Lactic acidosis and Megaloblastic anemia due to vitamin B12 deficiency are the major adverse effects of these drugs Lactic acidosis is more likely to occur in the presence of hepatic and renal impairment or alcohol ingestion