The primary mechanism of action of Ofloxacin appears to be the specific inhibition of DNA gyrase (topoisomerase II). This enzyme is responsible for the negative super coiling of the bacterial DNA and consequently for its topological configuration, governing functions such as RNA transcription, protein synthesis, DNA replication and repair functions. The nitro group in ornidazole is reduced to more reactive amine that attacks the microbial DNA that brings about loss of helical structure of DNA and subsequent DNA breakage.
The antibacterial and antiprotozoal activity of Mebatic is due to synergistic effect of Ofloxacin, Ornidazole. Mebatic acts by inhibiting DNA gyrase, a type II topoisomerase and topoisomerase IV, which is an enzyme necessary to separate replicated DNA, thereby inhibiting cell division also interferes with DNA replication by inhibiting an enzyme complex called DNA gyrase.
Plasma half life of Ofloxacin is 9 hours in Mebatic after infusion and elimination is mainly by renal excretion. The half life of Ornidazole is about 13 hours. Eighty five (85%) of a single dose is eliminated within the first 5 days, most of this being metabolized. 4% of the dose is excreted as unaltered substance in the urine. Ornidazole is mainly metabolized to 2-hydroxymethly and a-hydroxymethyl derivatives in the liver. Both main metabolites are less active against Trichomonas vaginalis and anaerobic bacteria than the unchanged ornidazole.