Which of the following anti-diabetic drugs can cause vitamin B12 deficiency?: (A) Glipizide, (B) Acarbose, (C) Metformin, (D) Pioglitazone
Answer is C. Ans. (C) Metformin(Ref: Goodman Gilman 12/e p1259, KDT 8/e 299)Lactic acidosis (more with phenformin) and megaloblastic anemia (more with metformin) 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.