[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Pharmacology](https://durgical.com/en/pharmacology/) › [Monobactams](https://durgical.com/en/pharmacology/classes/monobactams/) › Aztreonam + avibactam

# 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.

Updated Nov 1, 2026

Also called: aztreonam/avibactam

## Quick facts

**Group**
[Monobactams](https://durgical.com/en/pharmacology/classes/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.

On this page

- The basics Mechanism of action
- Indications
- Adverse effects
- Pharmacokinetics
- Memory aid

- Safety Contraindications
- Key interactions
- What is monitored
- Administration and safety
- Nursing care

- Study Test yourself

- Connections Connections

## Mechanism of action

✂**Gram-negative PBP3 (aztreonam) and class A, C and some D beta-lactamases (avibactam)**Aztreonam + avibactam

ⓘ The figure shows aztreonam bound to Pseudomonas aeruginosa PBP3; avibactam bound to the KPC-2 carbapenemase is shown on the ceftazidime with avibactam page.

**Target in 3D:** Gram-negative PBP3 (aztreonam) and class A, C and some D beta-lactamases (avibactam). PDB structure 3PBS (RCSB PDB, public domain). [View the structure at RCSB PDB](https://www.rcsb.org/structure/3PBS) · Drag to rotate · pinch to zoom

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 →](https://durgical.com/en/conditions/intra-abdominal-abscess/)

## Adverse effects

### Common

- Diarrhoea
- Fever
- Infusion-site reactions

### Serious (rare, important)

- Severe allergic reactions and skin reactions with blistering or peeling
- Clostridioides difficile diarrhoea
- Anaemia (tiredness, pallor, tachycardia, breathlessness)
- Liver injury

## 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.

## Memory aid

«AZtreonam + AVIbactam, from A to Z»: aztreonam dodges metallo-beta-lactamases and avibactam disarms all the others.

## 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.

[Add to my cards (3)](https://durgical.app/estudiar/?add=/en/pharmacology/aztreonam-avibactam/)

[More Pharmacology questions →](https://durgical.com/en/practice/?f=pharmacology)

## Connections

## Related drugs 3

- [Aztreonam](https://durgical.com/en/pharmacology/aztreonam/)
- [Ceftazidime + avibactam](https://durgical.com/en/pharmacology/ceftazidime-avibactam/)
- [Imipenem + cilastatin + relebactam](https://durgical.com/en/pharmacology/imipenem-cilastatin-relebactam/)

## Related conditions 1

- [Intra-abdominal abscess](https://durgical.com/en/conditions/intra-abdominal-abscess/)

[← Back to the class: Monobactams](https://durgical.com/en/pharmacology/classes/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](https://medlineplus.gov/druginfo/meds/a625054.html) (MedlinePlus (U.S. National Library of Medicine), 2026); [Crystal structure of PBP3 complexed with aztreonam](https://www.rcsb.org/structure/3PBS) (RCSB Protein Data Bank, 2026).

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Representative model, for educational purposes only.

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Source: https://durgical.com/en/pharmacology/aztreonam-avibactam/
License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/pharmacology/aztreonam-avibactam/