Antibacterial Agents

Abstract

Antimicrobial chemotherapy has played a vital role in the treatment of human infectious diseases since the discovery of penicillin in the 1920s. This chapter provides an overview of the antibacterial agents currently marketed in the United States, with major emphasis on their mechanisms of action, spectra of activity, important pharmacologic parameters, and toxicities. The major antibacterial action of penicillins is derived from their ability to inhibit multiple bacterial enzymes, namely, penicillin‐binding proteins (PBPs), that catalyze the last steps of peptidoglycan synthesis. The penicillins have antibacterial activity against most Gram‐positive and many Gram‐negative and anaerobic organisms. Like the penicillins, cephalosporins act by binding to PBPs of susceptible organisms, thereby interfering with the synthesis of peptidoglycan of the bacterial cell wall. Clavulanic acid is a naturally occurring weak antimicrobial agent found initially in cultures of Streptomyces clavuligerus . Streptomycin, neomycin, kanamycin, tobramycin, and gentamicin are naturally occurring aminoglycosides.