Zithromax is used for:br Treating infections caused by certain bacteria. It may also be used for other conditions as determined by your doctor.Zithromax is a macrolide antibiotic. It slows the growth of, or sometimes kills, sensitive bacteria by reducing the production of important proteins needed by the bacteria to survive.br br How to use Zithromax:br Use Zithromax as directed by your doctor. Check the label on the medicine for exact dosing instructions.br br * Zithromax is usually given as an injection at your doctor"s office, hospital, or clinic. If you will be using Zithromax at home, a health care provider will teach you how to use it. Be sure you understand how to use Zithromax . Follow the procedures you are taught when you use a dose. Contact your health care provider if you have any questions.br * Do not use Zithromax if it contains particles, is cloudy or discolored, or if the vial is cracked or damaged.