Cefapirin (INN, also spelled cephapirin) is an injectable, first-generation cephalosporin antibiotic. It is marketed under the trade name Cefadyl. Production for use in humans has been discontinued in the United States.[1]

It also has a role in veterinary medicine as Metricure, an intrauterine preparation, and combined with prednisolone in Mastiplan, an intramammary preparation. Both are licensed in cattle.


Cephapirin synthesis:[2] U.S. Patent 3,422,100 U.S. Patent 3,503,967 U.S. Patent 3,578,661

In one of the syntheses, 7-aminocephalosporanic acid (7-ACA) is reacted with bromoacetyl chloride to give the amide. The halo group is then displaced by 4-thiopyridine.[2]


  1. ^ http://www.accessdata.fda.gov/scripts/cder/drugsatfda/index.cfm?fuseaction=Search.Overview&DrugName=CEFADYL
  2. ^ a b