Azithromycin (Z-Pak) is one of America's most prescribed antibiotics. Learn its exact dosage, side effects, drug interactions, and the 2026 resistance warning doctors don't always share. Azithromycin (Zithromax) is a macrolide antibiotic. It's used to treat many types of infections in children and adults, including strep throat, sinus infection, and pneumonia. Overview: Azithromycin is an antibiotic that is used to treat certain bacterial infections. It works by stopping certain types of bacteria from making proteins they need to grow and multiply. Azithromycin and amoxicillin are two commonly prescribed antibiotics, each effective against a range of bacterial infections. The choice between them depends on the type of infection, a patient's allergy profile, and practical considerations like dosing convenience. Azithromycin, sold under the brand names Zithromax (in oral form) and Azasite (as an eye drop), is an antibiotic medication used to treat several bacterial infections. [9] Medscape - Infection-specific dosing for Zithromax (azithromycin), frequency-based adverse effects, comprehensive interactions, contraindications, pregnancy & lactation schedules, and cost. Azithromycin may cause diarrhea, and in some cases it can be severe. It may occur 2 months or more after you stop using this medicine. Do not take any medicine to treat diarrhea without first checking with your doctor. Diarrhea medicines may make the diarrhea worse or make it last longer. Azithromycin is in a class of medications called macrolide antibiotics. It works by stopping the growth of bacteria. Antibiotics such as azithromycin will not work for colds, flu, or other viral infections. Using antibiotics when they are not needed increases your risk of getting an infection later that resists antibiotic treatment. Find out how azithromycin treats infections and how to take it. NHS medicines information on azithromycin – what it's used for, side effects, dosage and who can take it. Azithromycin is an antibiotic that fights bacteria. Azithromycin is used to treat many different types of infections caused by bacteria, such as respiratory infections, skin infections, ear infections, eye infections, and sexually transmitted diseases.