Sulbactam-Durlobactam for Carbapenem-Resistant Acinetobacter

"Sulbactam-Durlobactam for Carbapenem-Resistant Acinetobacter" explores how randomized evidence has finally reshaped treatment of a notoriously difficult pathogen. Carbapenem-resistant Acinetobacter baumannii (CRAB) has long been among the most formidable gram-negative pathogens, and sulbactam-durlobactam has finally given clinicians an agent with randomized evidence behind it. Dr. Haidar explains that CRAB activates numerous resistance mechanisms simultaneously, which makes the specific mechanism less useful for guiding therapy than it is for Enterobacterales.

He recalls the early enthusiasm for cefiderocol in Acinetobacter infections and the unexpected mortality signal that emerged in clinical trials, which tempered that optimism. Dr. Haidar stresses that the first decision is whether a patient is truly infected, because CRAB frequently colonizes the airway and distinguishing colonization from ventilator-associated pneumonia is difficult. For confirmed infection, he identifies sulbactam-durlobactam as the drug of choice based on its pivotal trial, explaining that sulbactam itself provides antibacterial activity through penicillin-binding protein binding while durlobactam protects it. Dr. Haidar describes older regimens built on polymyxins, tetracyclines, or high-dose ampicillin-sulbactam as largely relegated to settings without access to the newer agent.

Dr. Tamma explains that the updated guidance now designates sulbactam-durlobactam combined with a carbapenem as the clearly preferred regimen. She notes that nearly all CRAB isolates are expected to be susceptible and encourages clinicians caring for critically ill patients to secure access even before susceptibility results return. Dr. Shields explains why the carbapenem is added, citing how the agent was studied, coverage of companion gram-negative pathogens, and preclinical evidence that targeting multiple penicillin-binding proteins enhances bacterial killing. The panel concludes that intentionally designed combination therapy may benefit patients with severe CRAB infections, even though it challenges older teaching against combining beta-lactams.

The most contested recommendation in the guidance comes next in "Weighing Cefiderocol and Combination Therapy for Stenotrophomonas," with Dr. Pogue, Dr. Shields, and Dr. Tamma weighing in.