Azithromycin (equivalent to Azithro 250mg or 500mg) is a macrolide antibiotic commonly used to treat a variety of bacterial infections. It works by inhibiting bacterial protein synthesis, which prevents the growth of bacteria. Azithromycin is effective against respiratory tract infections like pneumonia, bronchitis, sinusitis, and pharyngitis, as well as skin infections, ear infections, sexually transmitted infections (STIs), and certain gastrointestinal infections. The 250mg dosage is typically prescribed for less severe infections, while the 500mg dosage is used for more serious infections. Azithromycin is usually taken once daily for a shorter duration (often 3-5 days), making it a convenient option for treating many infections with fewer doses compared to other antibiotics.