Known brand names include Zithromax.
A macrolide antibiotic for respiratory, ear, sinus, throat, skin, and sexually transmitted infections. Its long half-life allows short courses, such as a 5-day pack or a single dose. It is given by mouth or IV.
Azithromycin attaches to the part of the bacterial ribosome that builds proteins. It blocks protein making and also keeps that part of the ribosome from being put together. Without new proteins, the bacteria cannot grow. Bacteria can resist it by changing the spot where it binds, and bacteria that resist erythromycin usually resist it too.
Tissues such as the lungs, tonsils, and skin soak it up and release it slowly, so it stays in the body for days. People should start to feel better within the first few days of treatment. Allergic reactions to it sometimes come back after their treatment ends, and the label notes this may relate to how long it lingers, though that link is unproven. Like other drugs in its class, it can delay the heart's electrical recovery between beats, which is how it can trigger dangerous heart rhythms.
Azithromycin is an antibiotic for infections of the airways, sinuses, throat, ears, and skin. It treats pneumonia picked up outside the hospital, flares of chronic bronchitis, and ear infections in children. It also treats chlamydia and gonorrhea infections of the urethra or cervix, and chancroid, a bacterial infection that causes genital sores, in men. It works only against bacteria, so it does not help colds, flu, or other viral infections.
Children 6 months and older can take it for ear infections and pneumonia, and children 2 and older can take it for strep throat. For strep throat, it is an alternative when the usual first choice cannot be used. The IV form is given in the hospital to adults with pneumonia or pelvic infections who need IV treatment at first, with a second antibiotic added if bacteria that live without oxygen may be involved. The pills and liquid are not recommended for pneumonia too severe to treat by mouth, such as in people who need a hospital stay.
Nausea, diarrhea, vomiting, and stomach pain are the common side effects, and pain at the site with the IV form. The label treats dangerous heart rhythm changes as serious, along with a short-term rise in the risk of death from heart problems. It also warns about liver injury, serious allergic and skin reactions that can return, a stomach blockage in newborns, worse myasthenia gravis, C. difficile diarrhea, and hearing loss or ringing in the ears.