Mechanism Of Action Of Clarithromycin Clarithromycin is in a class of medications called macrolide antibiotics. It works by stopping the growth of bacteria. Clarithromycin prevents bacteria from multiplying by acting as a protein synthesis inhibitor. Therapeutic Indications Of Claritt XL 500 Mg Tablets It is used in the following infections: Throat infections (pharyngitis/tonsillitis) Respiratory tract infections: sinus infections, bronchitis, and pneumonia Uncomplicated skin infections Mycobacterial infections Pylori infection (along with other medicines) Middle ear infections in children (otitis media)