avibactam sodium + aztreonam: clinical use

Prescribing considerations

• Reserve use for infections within the licensed spectrum and follow antimicrobial stewardship and microbiology advice.
• For aerobic Gram-negative infection with limited options, involve a clinician experienced in infectious diseases.
• Coverage is poor or absent for most Acinetobacter species, Gram-positive organisms and anaerobes; assess whether additional antibacterial cover is needed.
• Review allergy history, renal function, interacting medicines and microbiology results before and during treatment.
• Account for sodium from the product and any sodium-containing diluent.

Contraindications and cautions

• Hypersensitivity to aztreonam, avibactam or the excipient arginine.
• Previous severe hypersensitivity, including anaphylaxis or a severe skin reaction, to another beta-lactam antibacterial.

Monitoring

• Creatinine clearance, particularly when renal function is unstable or nephrotoxic medicines are used.
• Liver enzymes, especially in hepatic impairment.
• Neurological status where renal impairment or possible excessive exposure is present.
• Clinical and microbiological response and emergence of non-susceptible organisms.
• Coagulation when an oral anticoagulant is used concurrently.
• New or persistent diarrhoea suggesting Clostridioides difficile-associated disease.

Clinical pharmacology

Both components are predominantly eliminated renally. Aztreonam activity is time-dependent; avibactam restores activity by inhibiting susceptible beta-lactamases.

Formulation and product differences

• The selected product is a fixed-ratio powder for concentrate for intravenous infusion.
• It requires reconstitution, dilution, visual inspection and aseptic preparation; each vial is single use.
• Unopened vials require refrigerated storage in the original package to protect them from light.
• The formulation contains arginine and contributes sodium; compatible diluents and in-use storage limits depend on preparation conditions.