ceftazidime-avibactam

Brand: Avycaz

Prototype: ceftazidime
Drug Class: beta-lactam/beta-lactamase inhibitor combination
Drug Family: antibiotic
Subclass: novel beta-lactam/beta-lactamase inhibitor
Organ Systems: infectious-disease

Mechanism of Action

Ceftazidime inhibits PBPs; avibactam is a non-beta-lactam beta-lactamase inhibitor that reversibly inhibits KPC, OXA-48, and AmpC carbapenemases, restoring ceftazidime's activity against carbapenem-resistant Enterobacteriaceae.

penicillin-binding proteins (PBPs)KPC/OXA-48/AmpC beta-lactamases

Indications

  • complicated UTI (cUTI)
  • complicated intra-abdominal infection (cIAI)
  • hospital-acquired pneumonia/VAP due to carbapenem-resistant organisms
  • KPC-producing Enterobacteriaceae infections

Contraindications

  • cephalosporin hypersensitivity

Adverse Effects

Common

  • diarrhea
  • nausea
  • vomiting
  • headache

Serious

  • C. difficile colitis
  • anaphylaxis
  • neurological adverse effects (seizures, encephalopathy)
  • renal impairment

Pharmacokinetics (ADME)

Absorption IV only
Distribution both components widely distributed; CSF penetration similar to ceftazidime
Metabolism ceftazidime: not metabolized; avibactam: minimal
Excretion renal (both components, unchanged); dose-critical adjustment in CKD
Half-life ceftazidime 2.7 h; avibactam 2.7 h
Onset immediate (IV)
Peak end of infusion
Duration 8 hours
Protein Binding ceftazidime 10%; avibactam 8%
Vd moderate

Drug Interactions

Drug / Agent Mechanism Severity
probenecid reduces renal excretion of avibactam minor
nephrotoxic agents additive renal toxicity risk moderate

Nursing Considerations

  1. Administer IV over 120 minutes (2-hour infusion) per prescribing information; administer each dose precisely on schedule for severe infections.
  2. Renal dose adjustment is mandatory; use adjusted body weight for patients with obesity; consult pharmacist for dosing in CRRT.
  3. Monitor for neurological adverse events including seizures, particularly in patients with renal impairment where accumulation of ceftazidime can occur.
  4. Obtain cultures before starting therapy; monitor for development of resistance during treatment.

Clinical Pearls

  • Ceftazidime-avibactam is a key agent in the armamentarium against carbapenem-resistant Enterobacteriaceae (CRE) producing KPC enzymes.
  • Avibactam does NOT inhibit metallo-beta-lactamases (NDM, VIM, IMP); ceftazidime-avibactam will not be effective against NDM-producing organisms without combination therapy.

Safety Profile

Pregnancy generally-safe
Lactation use-with-caution
Renal Adjustment Required
Hepatic Adjustment Not required
TDM Not required
Guideline Update pending