About roxithromycinit is a semi-synthetic macrolide, antibiotic.mechanism of action of roxithromycinroxithromycin is a semi synthetic long acting macrolide antibiotic. it binds to the 50s sub unit of bacterial ribosome and inhibits translocation.ie: they interfere with the transfer of the newly formed peptide chain from the a site to the p site and fails to expose the a site .so that a site is unable to bind with the next aminoacyl t rna complex. this leads to premature termination of amino acid chain and there by inhibits protein synthesis.indications for roxithromycin1. pneumonia 2. tonsilitis 3. pharyngitis 4. bronchitis 5. ent infection 6. tetanus 7. diphtheria 8. sinusitis 9. gonorrhea 10. wound and burn infection 11. skin and soft tissue infections 12. pertusis 13. urogenital infection