Cefdinir monohydrate is the salt form of Cefdinir (free base), a semi-synthetic cephalosporin and a beta-lactam antibiotic with bactericidal activity. Cefdinir's effect is dependent on its binding to penicillin-binding proteins (PBPs) located in the bacterial cytoplasmic membrane. Binding results in the inhibition of the transpeptidase enzymes, thereby preventing cross-linking of the pentaglycine bridge with the fourth residue of the pentapeptide and interrupting consequent synthesis of peptidoglycan chains. As a result, cefdinir inhibits bacterial septum and cell wall synthesis formation.