CEFAPIRIN

Antimicrobial activity

Its antibacterial spectrum is almost identical to that of cefalotin, but it is more labile to staphylococcal β-lactamase. Intramuscular injections can be painful. A peak plasma concentration of 15–25 mg/L is obtained 0.5 h after intramuscular injection of 1 g. The plasma half-life is 0.4–0.8 h. It is c. 50% plasma protein bound and metabolized to the desacetyl form. The metabolite accounts for almost half the drug in the urine. Less than 1% of the dose appears in the bile.
A serum-sickness-like illness analogous to that seen with cefalotin has been observed. It is no longer used.