Piperacillin sodium is a semisynthetic broad-spectrum penicillin for parenteral use derived from D(-)-α-aminobenzylpenicillin. Target: Antibacterial Piperacillin is anantibiotic. It is an extended-spectrum beta-lactam of the ureidopenicillin class.The chemical structure of Piperacillin and other ureidopenicillins incorporates a polar side chain that enhances penetration into Gram-(-) bacteria and reduces susceptibility to cleavage by Gram-(-) beta lactamase enzymes. These properties confer activity against the important hospital pathogen Pseudomonas aeruginosa. Thus Piperacillin is sometimes referred to as an anti-pseudomonal penicillin.When used alone, Piperacillin lacks strong activity against the Gram-(+) pathogenStaphylococcus aureus, as it Piperacillin is broken down by the Gram-(+) beta lactamases.