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
[{'content': 'All of the following drugs undergo hepatic metabolism before excretion, EXCEPT: \nSelect and explain. \nA. Phenytoin, B. Diazepam, C. Penicillin G, D. Cimetidine', 'role': 'user'}, {'content': 'Answer: C \nExplanation: The pharmacokinetics of Penicillin G is dominated by very rapid renal excretion. About 10% of the drug is eliminated by glomerular filtration and rest by tubular secretion. The plasma t1/2 of penicillin G in healthy adults is 30 minutes. Ref: Essentials of Medical Pharmacology By K D Tripathi, 5th Edition, Pages 364, 372, 589, 655', 'role': 'assistant'}]