Erythromycin is an antibiotic used to treat a variety of bacterial infections. It belongs to the macrolide class of antibiotics and works by stopping the growth of bacteria. Erythromycin is available in different forms, including tablets, capsules, ointments, and injections. It is commonly prescribed for infections such as respiratory tract infections, skin infections, and sexually transmitted infections. Erythromycin is a widely used and effective antibiotic that has been on the market for many years.