This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: JIPMER 2017, Subject name: Pharmacology
DPP-IV inhibitor that can be used in renal failure is: 
Select and explain. 
A. Linagliptin, B. Sitagliptin, C. Vildagliptin, D. Sexagliptin
A: Linagliptin
Answer: A: Linagliptin 
Explanation: Alogliptin, linagliptin, saxagliptin and sitagliptin are orally active dipeptidyl peptidase-4 (DPP-4) inhibitors used for the treatment of type 2 diabetes. Mechanism of action: These drugs inhibit the enzyme DPP-4, which is responsible for the inactivation of incretin hormones such as GLP-1. Prolonging the activity of Incretin hormones increases insulin release in response to meals and reduces inappropriate secretion of glucagon. These drugs are avoided in renal failure except linagliptin which can be use in renal failure.