Description a semi-synthetic cephalosporin antibiotic.mechanism of action cefradine is a first generation cephalosporin antibiotic with a spectrum of activity similar to cefalexin. cefradine, like the penicillins, is a beta-lactam antibiotic. by binding to specific penicillin-binding proteins (pbps) located inside the bacterial cell wall, it inhibits the third and last stage of bacterial cell wall synthesis. cell lysis is then mediated by bacterial cell wall autolytic enzymes such as autolysins- it is possible that cefradine interferes with an autolysin inhibitor.