ATCvet code: QJ01AA06

Oxytetracycline is a bacteriostatic antibiotic. It exerts its action by inhibiting the protein synthesis of the bacterial cell. Inhibition of bacterial protein synthesis results in disturbance of all functions necessary for the life of bacteria, especially cell-division, and the formation of the cell wall are impaired.

Resistance is usually plasmid-mediated. Micro-organisms that have become resistant to one tetracycline frequently exhibit resistance to the others.

Absorption of oxytetracycline following intramuscular injection of CYCLOSOL LA is fast. In pigs the Cmax is measured within 2-3 hours; the Cmax is approximately 4 µg/ml. In cattle absorption is somewhat slower; the Cmax is measured after 3-5 hours; the Cmax is approximately 3-6 µg/ml.

A plasma concentration of 0.5 µg/ml or more is maintained for 72 hours in cattle and pigs. Concentrations of 0.1 μg/ml are maintained for 5 days. Bioavailability of CYCLOSOL LA is approximately 100%.
High concentrations of oxytetracycline are detectable in kidney, liver, and urine, but oxytetracycline is widely distributed in the body, including lungs and muscle. The placenta is readily passed by oxytetracycline and concentration in the foetal blood may reach that of the maternal circulation.
Oxytetracycline apparently is not metabolized in vivo and is eliminated primarily unchanged, via glomerular filtration. It is also excreted into the GI tract via both biliary and nonbiliary routes and may become inactive after chelation with faecal material.