Piperacillin and tazobactam is a combination antibiotic commonly used to treat a wide range of bacterial infections. Piperacillin is a broad-spectrum penicillin antibiotic that targets bacterial cell wall synthesis, while tazobactam is a beta-lactamase inhibitor that protects piperacillin from bacterial enzymes that would otherwise degrade it. This combination is effective against infections caused by Gram-positive and Gram-negative bacteria, including pneumonia, urinary tract infections, intra-abdominal infections, and skin infections. It's often used in hospital settings for serious or resistant infections, such as sepsis or complicated intra-abdominal infections, and is generally administered intravenously for optimal effect.