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 of the following antimicrobial agents do not require reduction in dose in patients with renal failure? 
Select and explain. 
A. Rifampicin, B. Fluconazole, C. Vancomycin, D. Imipenem
A: Rifampicin
Answer: A: Rifampicin 
Explanation: Rifampicin is primarily metabolized in the liver and excreted in bile. Rifampicin does not require dosage adjustment in Renal failure. Ref: Essentials of Medical Pharmacology By K D Tripathi, 5th Edition, Pages 667, 700, 719, 721; KDT 6th Edition, Page 741