Aztreonam with avibactam

How it works

Aztreonam inhibits Gram-negative cell-wall synthesis by binding penicillin-binding protein 3 and is stable to metallo-beta-lactamases, while avibactam protects it by inhibiting co-produced serine beta-lactamases such as ESBLs, AmpC and KPC enzymes.

Prescribing in practice

• Reserve for severe Gram-negative infections with limited alternatives and use under specialist microbiology or infectious-disease guidance to preserve activity against multidrug-resistant organisms.
• Aztreonam has a monobactam structure with low cross-reactivity to penicillins and cephalosporins, but caution is still advised in patients with severe beta-lactam hypersensitivity and it should be avoided with prior aztreonam allergy.
• Dose adjustment is required in renal impairment as both components are renally cleared.

Monitoring

Monitor renal function, clinical and microbiological response, and full blood count and liver enzymes during prolonged therapy.

Counselling the patient

• This is a hospital intravenous antibiotic reserved for difficult resistant infections.
• Report any rash, breathing difficulty, or new or worsening diarrhoea promptly.

Evidence & guidelines

Approval was supported by the REVISIT and ASSEMBLE trials demonstrating activity against serious infections including metallo-beta-lactamase-producing Enterobacterales.