Clarithromycin 250mg is a macrolide antibiotic used to treat bacterial infections of the respiratory tract (such as bronchitis and community‑acquired pneumonia), sinuses, throat, ears (otitis media), skin, and soft tissues. It is also used in combination therapy to eradicate Helicobacter pylori associated with peptic or duodenal ulcers. In people with advanced HIV, clarithromycin treats and helps prevent disseminated Mycobacterium avium complex (MAC) infections. It works by inhibiting bacterial protein synthesis, stopping bacterial growth. Clarithromycin is ineffective for viral illnesses and should be used only as prescribed for suspected or confirmed bacterial infections.