Fetroja Coverage for CRAB and MDR Proteus
Cefiderocol Activity Against CRAB
- The Infectious Diseases Society of America recommends against using cefiderocol for CRAB treatment despite its in vitro activity 2
- Clinical data for cefiderocol in CRAB infections remain limited, and treatment-emergent resistance has been documented, particularly in strains carrying blaNDM-1 carbapenemases and mutations in the AmpC gene 1
Recommended Treatment Strategy for CRAB
- First-line therapy for CRAB should be high-dose ampicillin-sulbactam (6-9 g sulbactam per day) if the organism is sulbactam-susceptible 1
- Combination therapy is strongly preferred over monotherapy for CRAB infections 3, 1
- Minocycline has 60-80% in vitro susceptibility against CRAB and represents a valid combination partner, with accumulating evidence supporting its use in serious CRAB infections 1
Critical Dosing Considerations
- Ensure sulbactam dosing reaches 6-9 g/day (typically ampicillin 18 g/sulbactam 9 g per day in divided doses) for adequate CRAB coverage 1
- Consider therapeutic drug monitoring if available, particularly for ensuring adequate sulbactam exposure 2
Alternative Considerations if Treatment Fails
- Colistin-based combination therapy (colistin plus carbapenem) represents the guideline-recommended alternative for CRAB bloodstream infections, though with weak evidence 1
- Avoid tigecycline monotherapy for CRAB pneumonia due to higher treatment failure rates compared to combination regimens 3, 1
Common Pitfalls
- Polymyxin monotherapy should be avoided for severe infections—always use combination therapy if polymyxins are employed 4