Zithromax Susp 200mg/5ml 15ml contains Azithromycin 200mg/5ml which treats bacterial infections. It treats bacterial infections of tonsils, sinus, ear, nose, and throat. Also, it treats infections of the skin and soft tissues, windpipe and lungs (pneumonia). It works by preventing synthesis of essential proteins required by bacteria to carry out vital functions. Thus, it stops the bacteria from growing, and prevents the infection from spreading.