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
Drug of choice for chylamydial trachomatis is: March 2007 
Select and explain. 
A. Penicilin, B. Erythromycin, C. Vancomycin, D. Azithromycin
D: Azithromycin
Answer: D: Azithromycin 
Explanation: Ans. D: Azithromycin Because of higher efficacy, better gastric tolerance and convenient once a day dosing, azithromycin is now preferred over erythromycin as first choice drug for infections such as: Legionnaires' pneumonia Chlamydia trachomatis Donovanosis caused by calymmatobacterium granulomatis Chancroid and PPNg urethritis.