This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Chemotherapy: General Principles, Subject name: Pharmacology
Carbenicillin: 
Select and explain. 
A. Is effective in pseudomonas infection, B. Has no effect in Proteus infection, C. Is a macrolide antibiotic, D. Is administered orally
A: Is effective in pseudomonas infection
Answer: A: Is effective in pseudomonas infection 
Explanation: Ans. (A) Is effective in pseudomonas infection(Ref: KDT 8/e p773)Carbenicillin is a penicillin congener effective against pseudomonas and indole positive proteus which are not inhibited by penicillin G or ampicillin/amoxicillin.It is inactive orally and excreted rapidly in urine. It is sensitive to penicillinase and acid, so administered parenterally as sodium salt.