Azithromycin is a prescription medication used to treat many bacterial infections such as those of the lungs and airways, eyes, ears, sinuses, skin, throat, and infections from sexually transmitted diseases. Azithromycin belongs to a group of drugs called macrolide antibiotics, which stop the growth of bacteria.

This medication comes in tablet, oral (by mouth) suspension, eye drops, and injection forms. The tablets and regular suspensions are taken once a day, with or without food. The extended release suspension is taken once only on an empty stomach. The eye drops are used in the affected eye twice a day. The injection is given by a healthcare professional.

Common side effects of azithromycin include nausea, vomiting, diarrhea, stomach pain, and headache. Eye irritation is the common side effect of the eye drop form.