Tazobactam is a compound that inhibits the action of bacterial β-lactamases. It is one of the preferred antibiotic treatments for community-acquired pneumonia (CAP) caused by Pseudomonas aeruginosa. It broadens the spectrum of piperacillin by making it effective against organisms that express β-lactamase and would normally degrade piperacillin.Tazobactam sodium is a derivative of the penicillin nucleus and is a penicillanic acid sulfone. Piperacillin-tazobactam is a beta-lactam/beta-lactamase inhibitor combination with a broad spectrum of antibacterial activity that includes Gram-positive and -negative aerobic and anaerobic bacteria. Piperacillin-tazobactam retains its in vitro activity against broad-spectrum beta-lactamase-producing and some extended-spectrum beta-lactamase-producing Enterobacteriaceae, but not against isolates of Gram-negative bacilli harboring AmpC beta-lactamases.