ATC Vet Code:QJ51DB08
Pharmacotherapeutic group
Antibacterial for intramammary use, first-generation cephalosporins.
Pharmacodynamic properties
Cefapirin is bactericidal with a time dependant mechanism of action and is characterised by its broad therapeutic spectrum of activity. Cefapirin is a first-generation cephalosporin which acts via inhibition of the synthesis of bacterial cell walls. There is low cross-allergy between cephalosporins and penicillins (6 to 16%).
Three mechanisms of resistance to cephalosporin are known so far: reduced permeability of the cell wall, enzymatic inactivation and change of specific penicillin binding sites. In Gram-positive bacteria and particularly staphylococci, the main cephalosporin resistance mechanism is through alteration of penicillin binding proteins. Resistance of Gram-negative bacteria resistance consist largely in the production of β-lactamases.
Cefapirin is usually effective against Staphylococcus aureus (including penicillinase positive strains), coagulase negative staphylococci, Streptococcus agalactiae and uberis.
The resistance situation against Streptococci remains favourable while for Staphylococci the resistance situation can be more variable between geographical regions or individual herds.
An overview of the MIC50 and MIC90 values of the targeted mastitis pathogens collected in Europe between 2015 and 2016 by the VetPath programme of the
European Animal Health Study Centre (CEESA) can be summarised as follows:
Bacteria | No of strains | MIC50 | MIC90 |
S. aureus | 247 | 0.25 | 0.25 |
Coagulase negative staphylococci | 189 | 0.12 | 0.25 |
S. agalactiae | 33* | 0.12 | 0.25 |
S. dysgalactiae | 132 | ≤0.03 | ≤0.03 |
S. uberis | 208 | 0.25 | 0.25 |
Pharmacokinetic particulars
At treatment during the dry period, therapeutically effective cefapirin concentrations in milk are maintained for at least 7 days. Protein binding in milk is 60 – 75%.
Maximum blood levels of 0.04 to 0.32 µg/ml were measured after 4 to 6 hours. Blood concentrations declined to below the limit of detection after 48 hours. The main metabolite of cefapirin is desacetyl-cefapirin, which is microbiologically active. After resorption from the udder, parent substance and metabolite are mainly excreted via the kidneys; to a lesser extend via the bile, and, after the start of the lactation period, also with the milk. Cefapirin concentrations above 0.02 µg/ml have been found in urine for up to 20 days.