About clarithromycinit is a new macrolide antimicrobial drug.it is the most effective macrolide against haemophilus influenzae, chlamydia trachomaitis and chlamydia pneumoniae.mechanism of action of clarithromycinclarithromycin is a member of 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 trna complex. this leads to premature termination of amino acid chain and there by inhibits protein synthesis.indications for clarithromycin1.tonsilitis 2.pharyngitis 3.pneumonia 4.skin and soft tissue infections 5.bronchitis 6.otitis media 7.prophylaxis of mac 8.leprosy 9.acne 10.nocardiosis