Piperacillin-Tazobactam (Polymicrobial Open Fracture Infections)

How it works

Piperacillin inhibits bacterial cell-wall synthesis via penicillin-binding proteins, while tazobactam inhibits many beta-lactamases to protect piperacillin, giving broad Gram-positive, Gram-negative and anaerobic cover.

Prescribing in practice

• Contraindicated in patients with severe penicillin or beta-lactam allergy, as serious cross-reactive hypersensitivity can occur.
• Adjust the dose in renal impairment and use under microbiology and stewardship guidance with timely de-escalation once cultures return.
• Concurrent use can raise the risk of acute kidney injury when combined with vancomycin, so monitor renal function closely.

Monitoring

Monitor renal function, full blood count and inflammatory markers during therapy, especially on prolonged courses.

Counselling the patient

• Report any rash, swelling or breathing difficulty as a possible allergic reaction.
• New or persistent diarrhoea should be reported as a possible bowel infection.
• The antibiotic is being targeted once swab and culture results are available.

Evidence & guidelines

Broad-spectrum cover for open-fracture infection is supported by UK orthopaedic-trauma and antimicrobial guidance, with prompt culture-guided de-escalation.