Carbapenem-Resistant Acinetobacter baumannii Antibiotic Recommendations
Sulbactam-durlobactam is recommended as the preferred agent for carbapenem-resistant Acinetobacter baumannii (CRAB) infections, given in combination with imipenem-cilastatin or meropenem. [1]
When sulbactam-durlobactam is not available, high-dose ampicillin-sulbactam is recommended as a component of combination therapy (plus at least one additional active agent). [1]
Medication Selection Algorithm
Recommended regimen components for CRAB therapy are based on availability and susceptibility. [1]
- Sulbactam-durlobactam (preferred) with imipenem-cilastatin or meropenem. [1]
- High-dose ampicillin-sulbactam as an alternate agent when sulbactam-durlobactam is unavailable, used as part of combination therapy. [1]
- Additional combination options when sulbactam-durlobactam is not used include polymyxin B, minocycline, tigecycline, or cefiderocol (selected based on susceptibility and clinical context). [1]
For CRAB treated in accordance with ESCMID guidance: [2]
- If CRAB is susceptible to sulbactam, ampicillin-sulbactam is recommended for HAP/VAP. [2]
- If CRAB is resistant to sulbactam, polymyxin or high-dose tigecycline can be used if active in vitro. [2]
Key Evidence Supporting This Recommendation
IDSA AMR guidance recommends sulbactam-durlobactam as preferred based on its role in CRAB-directed therapy. [1]
IDSA AMR guidance advises against routine use of carbapenem plus colistin or other regimens as components of routine CRAB therapy because benefit was not demonstrated in large clinical trials. [1]
Monotherapy Versus Combination Therapy
Combination therapy is recommended for CRAB infections when implementing CRAB-directed regimens in IDSA guidance. [1]
Ampicillin-sulbactam is recommended only as a component of combination therapy when used as an alternate to sulbactam-durlobactam. [1]
Important Clarifications or Nuances
IDSA AMR guidance suggests considering discontinuation of carbapenem after clinical improvement in prolonged CRAB infections (for example, osteomyelitis). [1]
In settings of resistance to sulbactam-durlobactam (MICs ≥16/4 µg/mL), IDSA guidance suggests considering optimally-dosed non-sulbactam-based combinations, such as cefiderocol, minocycline, tigecycline, or polymyxin B. [1]
ESCMID guidance conditionally recommends against cefiderocol for CRAB infections. [2]
Initiation Thresholds or Indications
Sulbactam-durlobactam is recommended for CRAB infections when feasible, using imipenem-cilastatin or meropenem as the companion agent. [1]
High-dose ampicillin-sulbactam is recommended only when unavailability of sulbactam-durlobactam precludes its use. [1]
Polymyxin or high-dose tigecycline is recommended only if active in vitro in cases of CRAB resistant to sulbactam (ESCMID). [2]
Common Pitfalls to Avoid
Nebulized antibiotics are not recommended as adjunctive therapy for CRAB pneumonia due to lack of benefit observed in clinical trials and concerns regarding respiratory complications such as bronchoconstriction. [1]
IDSA AMR guidance advises against using meropenem or imipenem-cilastatin as routine components of CRAB therapy when not administered with sulbactam-durlobactam (with the notable exception of combination with sulbactam-durlobactam). [1]
ESCMID guidance recommends against polymyxin-meropenem combination therapy and polymyxin-rifampin combination therapy for CRAB infections. [2]
Target Blood Pressure
Not applicable.