Praxis Medical Insights

Est. 2024 • Clinical Guidelines Distilled

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Last Updated: 8/18/2025

Treatment of Carbapenem-Resistant Acinetobacter baumannii Infections

First-Line Therapy

  • The Infectious Diseases Society recommends colistin-based combination therapy as the primary treatment approach for Carbapenem-Resistant Acinetobacter baumannii (CRAB) infections, with colistin with or without carbapenems, plus adjunctive inhaled colistin therapy (Weak recommendation, low quality of evidence) 1
  • Colistin-carbapenem based combination therapy is recommended for CRAB infections (Weak recommendation, low quality of evidence) 1

Alternative Options

  • Tigecycline-based combination therapy is considered an alternative option, except as monotherapy for pneumonia, and consideration of MIC values is recommended before initiating tigecycline (better outcomes when MIC ≤2 mg/L) 2
  • Both tigecycline-based and polymyxin-based combination therapies are considered equally preferable, with the choice depending on patient condition 2

Special Considerations

  • Polymyxins should be used cautiously in patients with renal insufficiency 2
  • Tigecycline should be used cautiously in patients with liver insufficiency 2

Treatment of CRE Infections

  • Ceftazidime-avibactam 2.5g IV q8h is recommended for CRE bloodstream infections (Weak recommendation, low quality evidence) 1
  • Ceftazidime-avibactam 2.5g IV q8h is recommended for complicated urinary tract infections caused by CRE (Weak recommendation, very low quality evidence) 1
  • Ceftazidime-avibactam 2.5g IV q8h is recommended for complicated intra-abdominal infections caused by CRE when combined with metronidazole (Weak recommendation, very low quality evidence) 1

Combination Therapy

  • Combination therapy is generally preferred over monotherapy for CRAB infections to reduce the risk of treatment failure and emergence of resistance 1, 2
  • Ceftazidime-avibactam combined with aztreonam shows synergy and is associated with lower mortality rates for CRE with metallo-β-lactamases 2, 3

Consultation and Testing

  • Infectious disease consultation is highly recommended for management of infections caused by multidrug-resistant organisms 1
  • Antimicrobial susceptibility testing or genotypic characterization of resistance should guide selection of antimicrobial agents 1

REFERENCES

3

Antimicrobial Treatment Guidelines [LINK]

Praxis Medical Insights: Practical Summaries of Clinical Guidelines, 2025