Used to treat a variety of bacterial infections, including respiratory tract infections, skin infections, ear infections, and sexually transmitted infections like chlamydia. It is effective against both gram-positive and some gram-negative bacteria. Commonly prescribed for community-acquired pneumonia, bronchitis, and sinusitis. Also used in patients allergic to penicillin. Available in oral, tablet, and liquid forms, it has a long half-life, allowing for shorter treatment courses, often once daily for a few days.