Cefapirin, a first generation cephalosporin, is a broad spectrum antibiotic with bactericidal action against gram-positive and gram-negative bacteria. Cefapirin is resistant to the action of penicillinase.

After intra-uterine treatment systemic absorption is low, which is reflected by the low plasma levels of cefapirin observed shortly after treatment. Twelve hours after treatment, cefapirin levels in plasma are below detectable levels.

After intra-uterine administration of Metricure, high cefapirin concentrations are observed in endometrium.

Cefapirin concentrations in endometrium can be observed up to 24 hours