Doxycycline, an active substance of the drug, is a semisynthetic antibiotic that belongs to the 3rd generation of the tetracycline group and is effective against Gram-positive and Gram-negative microbes including Escherichia coli., Haemophilus spp., Pasteurella spp., Salmonella spp., Staphylococcus spp., Streptococcus spp., Leptospira spp., Chlamidia spp, Clostridium perfringens, Listeria monocytogenes, Corynebacterium pyogenes, Rickettsiae spp, as well as Mycoplasma spp.
The mechanism of bacterial growth-inhibition activity of doxycycline involves inhibition of enzymes that act as catalysts for binding aminoacetyl-RNA to ribosomal acceptors, which leads to blocking of interactions between aminoacyl-transport RNA with messenger RNA and disruption of microbial cell protein synthesis. After parenteral administration of the drug, doxycycline is quickly and fully absorbed from the injection site and reaches its therapeutic concentration after 0.5-1 hour. It easily penetrates into most animal organs and tissues and undergoes metabolism in the liver, forming inactive metabolites. The drug is eliminated mostly with bile and partially with urine.