Pivmecillinam is a mecillinam prodrug, a pivaloyloxymethyl ester of amdinocillin that is well absorbed orally, but broken down to amdinocillin in the intestinal mucosa. It is active against gram-negative organisms and used as for amdinocillin. [PubChem] (en)
Pivmecillinam interferes with the biosynthesis of the bacterial cell wall however its activity is slightly different from that of other penicillins and cephalosporins (en)