About oxytetracyclinetetracycline derivative, a broad spectrum antibiotic.mechanism of action of oxytetracyclineoxytetracycline is a broad spectrum antibiotic which has action against both gram positive organisms & gram negative organisms. it exerts its bacteriostatic action by accumulating inside the bacteria through specific transporter protein & inhibits bacterial protein synthesis by attaching to 30 s subunit of bacterial ribosome (which are absent in mammals).oxytetracycline interfering the attachment of aminoacyl-trna to the mrna-ribosome complex and peptide chain fails to grow. it chelates cations like ca & mg and inhibits functioning of various enzymes & ribosome.indications for oxytetracycline1.pneumonia 2.ophthalmic infections 3. rickettsial infections 4.psittacosis 5.brucellosis 6.sexually transmitted diseases like syphilis, gonorrhea, chancroid 7.urinogenital tract infections 8.in lympho granuloma veneram 9.gastrointestinal tract infections