This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pharmacology
Which one of the following statements about biguanides is not true - 
Select and explain. 
A. Don't stimulate insulin release, B. Don't stimulate insulin release, C. Renal Dysfunction is not a contraindication for their use, D. Renal Dysfunction is not a contraindication for their use
C: Renal Dysfunction is not a contraindication for their use
Answer: C: Renal Dysfunction is not a contraindication for their use 
Explanation: Ans. is 'c' i.e., Renal dysfunction is not a contraindication for their use o Biguanides are contraindicated in hypotensive states, cardiovascular, respiratory, hepatic and renal disease and in alcoholics because of increased risk of lactic acidosis. About other options o Biguanides do not cause insulin release. o Their major action is to suppress hepatic gluconcogenesis (Decreased hepatic glucose production). o Biguanides may be combined with sulfonylureas and thiazolidinediones in type 2 DM in whom oral monotherapy is ineffective.