Aztreonam + avibactam
Monobactams
Monobactams
A monobactam with a beta-lactamase inhibitor for gram-negatives producing metallo-beta-lactamases, which destroy almost every other beta-lactam.
Also called: aztreonam/avibactam
Quick facts
- Group
- Monobactams
- Target
- Gram-negative PBP3 (aztreonam) and class A, C and some D beta-lactamases (avibactam)
- Used for
- Serious intra-abdominal infections
- Key effects
- Diarrhoea · Fever · Infusion-site reactions
- Monitor
- Kidney and liver function · Blood count
- ATC
- J01DF51
No doses: the clinician sets them by the current guideline.
Mechanism of action
The figure shows aztreonam bound to Pseudomonas aeruginosa PBP3; avibactam bound to the KPC-2 carbapenemase is shown on the ceftazidime with avibactam page.
Aztreonam acylates gram-negative PBP3 and blocks wall division. It resists metallo-beta-lactamases, but extended-spectrum beta-lactamases and KPC, which often travel with them, destroy it. Avibactam, a non-beta-lactam inhibitor, blocks those class A and C enzymes and some class D ones; so the pair acts against bacteria that make metallo-beta-lactamases and other beta-lactamases at the same time.
- Metallo-beta-lactamases do not hydrolyse aztreonam
- Avibactam blocks ESBLs, KPC and AmpC
- Intact aztreonam acylates PBP3
- The gram-negative bacterium cannot divide and dies
Indications
- Serious intra-abdominal infections by gram-negatives with few options, such as metallo-beta-lactamase producers Intra-abdominal abscess →
Adverse effects
Common
- Diarrhoea
- Fever
- Infusion-site reactions
Contraindications
- Severe allergy to aztreonam, avibactam or their ingredients
Key interactions
- Ceftazidime with avibactam
- Before this fixed combination, aztreonam was given alongside ceftazidime-avibactam for the same purpose; both products are not added together.
What is monitored
- Kidney and liver function
- Blood count
- Culture and susceptibility: kept for multidrug-resistant gram-negatives
Administration and safety
- Slow IV infusion of about 3 hours
- Kept, according to susceptibility testing, for gram-negatives with metallo-beta-lactamases or other extensive resistance
Nursing care
- Ask about beta-lactam allergy; aztreonam cross-reactivity is rare, except with ceftazidime and drugs with a similar side chain
- Watch for rash, blistering or trouble breathing
- Watch for watery or bloody diarrhoea
- Ask about liver or kidney disease
Pharmacokinetics
- Absorption
- IV only.
- Elimination
- Aztreonam leaves mostly unchanged in the urine.
Test yourself
Think of the answer, then tap the question to see it.
Why does aztreonam keep activity against metallo-beta-lactamases?
Its monobactam structure is stable to them, though not to ESBLs or KPC.
What does avibactam add to aztreonam?
It blocks the class A, C and some D beta-lactamases that often accompany metallo-beta-lactamases and would destroy aztreonam.
What advantage does aztreonam have in people with severe penicillin allergy?
It has almost no cross-reactivity with other beta-lactams, except ceftazidime and drugs with a similar side chain.
Connections
← Back to the class: Monobactams
Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.
Sources: Aztreonam and Avibactam Injection: MedlinePlus Drug Information (MedlinePlus (U.S. National Library of Medicine), 2026); Crystal structure of PBP3 complexed with aztreonam (RCSB Protein Data Bank, 2026).
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Representative model, for educational purposes only.