This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Pharmacokinetics, Subject name: Pharmacology
Drug, NOT metabolised by liver is : 
Select and explain. 
A. Penicillin G, B. Phenytoin, C. Erythromycin, D. Cimetidine
A: Penicillin G
Answer: A: Penicillin G 
Explanation: Ans. is 'a' Penicillin G Penicillin G is metalized mainly in kidneyApproximately 10% of the drug is eliminated by glomerular filtration and 90% by tubular secretionRest of the drugs given in the question erythromycin, cimetidine and phenytoin are metabolized in the liver.