This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cell Wall Synthesis Inhibitors, Subject name: Pharmacology
Following drugs are antipseudomonal except 
Select and explain. 
A. Carbenicillin, B. Piperacillin, C. Vancomycin, D. Azlocillin
C: Vancomycin
Answer: C: Vancomycin 
Explanation: VANCOMYCIN Vancomycin is drug which is not effective against Pseudomonas Not effective orally Causes Red man syndrome(vancomycin cause direct action on Mast cells and release histamine) Other toxic effects of vancomycin are chills, ototoxicity and nephrotoxicity. DOC- MRSA, antibiotic associated pseudomembranous enterocolitis.