Common colds, flu, or other types of viral infections. In the treatment of uncomplicated genital infections. The ability of composing proteins. Zithromax is an azalide antibiotic, a subclass of the macrolides. In the digestive system. Zithromax is an azalide antibiotic, a subclass of the macrolides. This drug is that it is found to be present in the body for a significant period of time after the required doses. Taking this medicine at the same time each day will make it easier to remember.