Piperacillintazobactam

Piperacillin-tazobactam is a combination antibiotic used to treat a variety of serious infections. It pairs piperacillin, a broad-spectrum penicillin, with tazobactam, a beta-lactamase inhibitor, to extend piperacillin’s activity against beta-lactamase–producing bacteria. The combination is typically administered by intravenous infusion.

Mechanism of action and spectrum: Piperacillin inhibits bacterial cell wall synthesis. Tazobactam blocks certain enzymes (beta-lactamases) that would otherwise destroy piperacillin, allowing activity against organisms that produce these enzymes. The regimen has a broad spectrum, covering many Gram-negative including Pseudomonas aeruginosa, as well as many Gram-positive cocci and anaerobes. It does not reliably cover methicillin-resistant Staphylococcus aureus (MRSA) or some Enterococcus species, and resistance can develop with misuse.

Indications: It is used for moderate to severe infections where resistant organisms are suspected or confirmed. Common indications include intra-abdominal infections, complicated and uncomplicated pneumonia (including hospital-acquired cases), gynecologic infections, skin and soft tissue infections, and septicemia. It may be chosen when a broad-spectrum, beta-lactam–beta-lactamase inhibitor therapy is appropriate.

Administration and pharmacokinetics: The drug is given by intravenous infusion, usually every 6–8 hours in adults, with dosing adjusted for renal function. Piperacillin-tazobactam is largely excreted by the kidneys. It is generally well tolerated, but safety in pregnancy should be assessed by a clinician.

Adverse effects and considerations: Common adverse effects include diarrhea, rash, and hypersensitivity reactions. Clostridioides difficile infection is a possible complication. Use with caution in patients with penicillin allergies; cross-reactivity is low but present. Interactions may include effects on renal clearance of certain drugs and reduced levels of valproic acid.