Zithromax (generic: azithromycin) is a prescription medication used to treat many bacterial infections such as bronchitis, pneumonia, sexually transmitted diseases, and infections of the ear, sinuses, skin, and throat. Zithromax belongs to a group of drugs called macrolide antibiotics. It works by preventing the growth of bacteria.

This medication comes in tablet and liquid forms. An extended-release liquid form (Zmax) is also available. Zithromax is usually taken once daily, with or without food. 

Additionally, this medication is available in an injectable form to be given directly into a vein (IV) by a healthcare professional.

Common side effects of Zithromax include diarrhea, stomach pain, and nausea.