Monobactam + beta-lactamase inhibitor Pregnancy: eMC §4.6: there are no or limited data from the use of aztreonam or avibactam in pregnant women. Animal studies with aztreonam do not indicate reproductive toxicity; animal studies with avibactam have shown reproductive toxicity without evidence of teratogenic effects. Aztreonam/avibactam should only be used during pregnancy when clearly indicated and only if the benefit for the mother outweighs the risk for the child. Breast-feeding: aztreonam is excreted in human milk at concentrations less than 1% of simultaneously obtained maternal serum; it is unknown whether avibactam is excreted in human milk and a risk to the breastfed child cannot be excluded — a decision must be made whether to discontinue breast-feeding or the therapy.

Aztreonam with avibactam

Brand names: Emblaveo

A fixed combination of the monobactam aztreonam with the non-beta-lactam beta-lactamase inhibitor avibactam, used intravenously for serious Gram-negative infections, including those caused by metallo-beta-lactamase-producing Enterobacterales where treatment options are limited.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: Loading dose aztreonam 2 g / avibactam 0.67 g, followed by maintenance doses of aztreonam 1.5 g / avibactam 0.5 g (patients with estimated creatinine clearance above 50 mL/min)

Route: Intravenous infusion over 3 hours

Frequency: Maintenance dose every 6 hours, beginning at the next dosing interval after the single loading dose

eMC §4.2 (Emblaveo 1.5 g/0.5 g powder for concentrate for solution for infusion). PRESCRIBING RESTRICTION: recommended for infections due to aerobic Gram-negative organisms in ADULT patients with limited treatment options, and only after consultation with a physician with appropriate experience in the management of infectious diseases. DURATION BY INDICATION (all on the same loading/maintenance regimen and 3-hour infusion every 6 hours): complicated intra-abdominal infection (cIAI) 5–10 days — to be used in combination with metronidazole when anaerobic pathogens are known or suspected to be contributing to the infectious process; hospital-acquired pneumonia including ventilator-associated pneumonia (HAP/VAP) 7–14 days; complicated urinary tract infection including pyelonephritis (cUTI) 5–10 days; infections due to aerobic Gram-negative organisms in patients with limited treatment options — duration in accordance with the site of infection, and may continue for up to 14 days. Creatinine clearance is calculated using the Cockcroft-Gault formula. ELDERLY: no dosage adjustment required based on age. HEPATIC IMPAIRMENT: no dosage adjustment required, but close monitoring is recommended as elevated liver enzymes have been observed. PAEDIATRIC: safety and efficacy in patients under 18 years of age have not yet been established and no data are available. SPECTRUM LIMITATION (§4.4): aztreonam has little or no activity against the majority of Acinetobacter spp., Gram-positive organisms and anaerobes — additional antibacterial medicinal products should be used when these pathogens are known or suspected to be contributing to the infectious process. NEUROLOGICAL RISK (§4.4): there have been reports of neurological sequelae with aztreonam (encephalopathy, confusion, epilepsy, impaired consciousness, movement disorders) in patients with renal impairment and in association with beta-lactam overdose. Concomitant nephrotoxic products (e.g. aminoglycosides) may adversely affect renal function. SOURCE NOTE: the eMC §4.5 interactions section was not captured in this bundle — clinician to review it in the SPC. The openFDA record fetched for this id is single-agent AZTREONAM FOR INJECTION (US labelling) and does not cover the aztreonam-avibactam combination; its doses must not be applied to this product.

Dose adjustments

Renal

eMC §4.2: no dosage adjustment in mild renal impairment (estimated CrCl above 50 to 80 mL/min or less). CrCl above 30 to 50 mL/min or less — loading 2 g/0.67 g then maintenance 0.75 g/0.25 g, 3-hour infusion, every 6 hours. CrCl above 15 to 30 mL/min or less — loading 1.35 g/0.45 g then maintenance 0.675 g/0.225 g, 3-hour infusion, every 8 hours. CrCl 15 mL/min or less on intermittent haemodialysis — loading 1 g/0.33 g then maintenance 0.675 g/0.225 g, 3-hour infusion, every 12 hours; both aztreonam and avibactam are removed by haemodialysis, so on haemodialysis days give the dose after the session. Aztreonam-avibactam should not be used in patients with CrCl 15 mL/min or less unless haemodialysis or another form of renal replacement therapy is initiated. These reduced-dose recommendations are based on pharmacokinetic modelling and simulation. There are insufficient data to make dosing recommendations for renal replacement therapy other than haemodialysis (e.g. continuous veno-venous haemofiltration or peritoneal dialysis); patients receiving continuous renal replacement therapy need a higher dose than patients on haemodialysis, and the dose should be adjusted guided by the CRRT clearance. Close monitoring of estimated creatinine clearance is advised.

Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

Hypersensitivity to the active substances or to any of the excipients (eMC §4.3)
Severe hypersensitivity (e.g. anaphylactic reaction, severe skin reaction) to any other type of beta-lactam antibacterial agent (e.g. penicillins, cephalosporins or carbapenems)

Side effects

Anaemia (6.9%, common) — also thrombocytosis, eosinophil count increased and prolonged prothrombin/activated partial thromboplastin time
Diarrhoea (6.2%, common) — also nausea, vomiting and abdominal pain; Clostridium difficile colitis and pseudomembranous colitis (uncommon/rare)
Alanine aminotransferase increased (6.2%) and aspartate aminotransferase increased (5.2%) — also transaminases increased, gamma-glutamyltransferase increased and blood alkaline phosphatase increased
Nervous system: dizziness, encephalopathy, headache, oral hypoaesthesia, dysgeusia, seizure and paraesthesia
Hypersensitivity: anaphylactic reaction and drug hypersensitivity; rash, angioedema, urticaria, pruritus, and rarely toxic epidermal necrolysis, exfoliative dermatitis and erythema multiforme. Local: phlebitis, thrombophlebitis, infusion site extravasation and injection site pain

Clinical monograph

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.

Reference: NICE TA evaluation; UKHSA AMR; BSAC; SmPC; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways