Pharmacotherapeutic group: Anti-infective for systemic use: amoxicillin and enzyme inhibitor.
ATC Vet Code: QJ01CR02
Pharmacodynamic properties
Amoxicillin is a beta-lactam antibiotic and its structure contains the beta-lactam ring and thiazolidine ring common to all penicillins. Amoxicillin shows activity against susceptible Gram positive bacteria and Gram negative bacteria.
Beta-lactam antibiotics prevent the bacterial cell wall from forming by interfering with the final stage of peptidoglycan synthesis. They inhibit the activity of transpeptidase enzymes, which catalyse cross-linkage of the glycopeptide polymer units that form the cell wall. They exert a bactericidal action but cause lysis of growing cells only.
Clavulanic acid is one of the naturally occurring metabolites of the streptomycete Streptomyces clavuligerus . It has structural similarity to the penicillin nucleus, including possession of a beta-lactam ring. Clavulanic acid is a beta-lactamase inhibitor acting initially competitively but ultimately irreversibly.
Clavulanic acid will penetrate the bacterial cell wall binding to both extracellular and intracellular beta-lactamases.
Amoxicillin is susceptible to breakdown by ß-lactamases produced by some bacterial species, and therefore combination with an effective ß-lactamase inhibitor (clavulanic acid) extends the range of bacteria against which it is active to include ß-lactamase producing species.
Pharmacokinetic properties
After parenteral administration of the maximum recommended dose to cattle, the following parameters were observed: Cmax of 1.69 µg/ml, Tmax of 2.67h, AUC of 30.59 µg/ml.h and t½ of 23.19h for amoxicillin and Cmax of 0.94 µg/ml, Tmax of 1.3h, AUC of 3.123 µg/ml.h and t½ of 1.71h for clavulanic acid.
After subcutaneous administration of the maximum recommended dose to dogs, the following parameters were observed: Cmax of 8.66 µg/ml, Tmax of 1.78 hours and AUC of 50.98 µg/ml.h for amoxicillin. Following either subcutaneous or intramuscular administration of the veterinary medicinal product to cats, both amoxicillin and clavulanic acid are well absorbed and well distributed in the tissues. The major route of elimination of amoxicillin and clavulanic acid is via the urine.