From the Guidelines
For treating Acinetobacter pneumonia, cefepime-sulbactam is generally preferred over ceftazidime-sulbactam due to its broader spectrum of activity and better outcomes against resistant strains. The recommended dosing for cefepime-sulbactam is typically 2g cefepime with 1g sulbactam every 8 hours (adjusted for renal function), administered intravenously for 7-14 days depending on clinical response. Ceftazidime-sulbactam (2g ceftazidime with 1g sulbactam every 8 hours) remains an alternative but may be less effective against certain resistant Acinetobacter strains. Both combinations work by the cephalosporin component targeting bacterial cell wall synthesis while sulbactam inhibits beta-lactamase enzymes that would otherwise inactivate the antibiotic.
Key Considerations
- Treatment should be guided by susceptibility testing whenever possible, as Acinetobacter baumannii is notorious for developing resistance 1.
- In severe cases or with highly resistant strains, combination therapy with an aminoglycoside or colistin might be necessary, although colistin's use is limited by its nephrotoxicity 1.
- Monitor renal function during treatment and adjust dosing accordingly, as both medications are primarily eliminated through the kidneys.
- Sulbactam has intrinsic activity against A. baumannii and may be a suitable alternative in directed therapy for A. baumannii at a MIC ≤4 mg/L 1.
Dosage and Administration
- The recommended dosage of sulbactam for severe infections is 9–12 g/day in 3 daily doses 1.
- A recent PK/PD study suggested that a 4-h infusion of 3 g of sulbactam every 8 h constitutes the best treatment option for isolates with a higher MIC of 8 mg/L 1.
Comparison of Treatments
- Clinical results using ampicillin-sulbactam to treat severe A. baumannii infections were similar to those obtained with imipenem 1.
- Ampicillin-sulbactam was more effective than polymyxins in a retrospective study that included CR Acinetobacter infections of diverse origins but excluding urinary tract infections 1.
- A randomized study evaluated the efficacy and safety of two sulbactam regimens in patients with VAP caused by multi-drug-resistant (MDR) A. baumannii, showing similar clinical and bacteriological cure rates with both regimens and excellent tolerance 1.
From the Research
Comparative Efficacy of Ceftazidime + Sulbactam versus Cefepime + Sulbactam
- The comparative efficacy of Ceftazidime (Ceftazidime) + Sulbactam (Sulbactam) versus Cefepime (Cefepime) + Sulbactam (Sulbactam) for treating Acinetobacter (Acinetobacter)-associated pneumonia is not directly addressed in the provided studies.
- However, the studies provide information on the efficacy of cefepime and ceftazidime in treating pneumonia, including those caused by Acinetobacter baumannii complex (ABC) 2, 3.
- Cefepime has been shown to be effective against Gram-negative organisms, including Pseudomonas aeruginosa, similar to ceftazidime 2.
- A study comparing cefepime and ceftazidime in the treatment of adult pneumonia found that cefepime had a higher cure rate (95% vs 60%) in patients with hospital-acquired pneumonia (HAP) 3.
- Another study discussed the potential effectiveness of sulbactam-durlobactam in treating pneumonia caused by carbapenem-resistant Acinetobacter baumannii (CRAB) 4, 5.
- The combination of cefepime with a beta-lactamase inhibitor, such as zidebactam, is also being explored as a potential treatment option for CRAB infections 6.
Treatment Options for Acinetobacter-Associated Pneumonia
- The treatment of Acinetobacter-associated pneumonia is challenging due to the high prevalence of carbapenem-resistant and extensively drug-resistant (CR/XDR) phenotypes 4, 5.
- Current treatment options include the use of novel antibiotics, such as cefiderocol and sulbactam-durlobactam, as well as combination therapy with other antibiotic classes 4, 6, 5.
- The development of new antimicrobials and adjuvant therapies is a priority for the treatment of CRAB pneumonia 5.