Comparative Effectiveness of Ampicillin-Sulbactam vs Ceftriaxone in Elderly CAP

Overview

In a large nationwide Japanese cohort of elderly patients hospitalized with community-acquired pneumonia (CAP), initial treatment with ampicillin-sulbactam was associated with higher in-hospital mortality compared to ceftriaxone. Additionally, ampicillin-sulbactam showed a numerically higher incidence of Clostridioides difficile infection during hospitalization.

Background

Community-acquired pneumonia is a significant cause of morbidity and mortality in older adults. Historically, anaerobic bacterial coverage was recommended for aspiration pneumonia, but recent evidence suggests routine anaerobic coverage may be unnecessary. Ampicillin-sulbactam and ceftriaxone are common empirical treatments for CAP, differing mainly in anaerobic coverage. This study used a target trial emulation approach to compare their effectiveness in elderly patients.

Data Highlights

Key Findings

• Ampicillin-sulbactam was associated with a significantly higher in-hospital mortality rate compared to ceftriaxone (10.5% vs 9.0%).
• The adjusted odds ratio for mortality with ampicillin-sulbactam was 1.19 (95% CI, 1.08–1.31), indicating increased risk.
• Incidence of Clostridioides difficile infection was numerically higher in the ampicillin-sulbactam group (0.6% vs 0.4%), with an adjusted odds ratio of 1.45 (95% CI, 0.99–2.11).
• These findings were consistent even among patients with risk factors for aspiration pneumonia.
• Current guidelines do not recommend routine anaerobic coverage for CAP unless complicated by lung abscess or empyema, aligning with the observed lack of benefit from ampicillin-sulbactam's broader anaerobic coverage.

Clinical Implications

Clinicians should consider ceftriaxone as the preferred initial empirical treatment for elderly patients hospitalized with CAP, given its association with lower mortality and potentially fewer Clostridioides difficile infections. Routine anaerobic coverage with ampicillin-sulbactam may not provide additional benefit and could increase risks. Treatment decisions should align with current guidelines that reserve anaerobic coverage for specific clinical scenarios.

Conclusion

In elderly patients hospitalized with community-acquired pneumonia, ceftriaxone demonstrated superior outcomes compared to ampicillin-sulbactam, supporting guideline recommendations against routine anaerobic coverage. These findings inform antibiotic selection to optimize patient outcomes and minimize adverse effects.

References

1. Kashiwagi et al. 2024 -- Comparative Effectiveness of Ampicillin-Sulbactam and Ceftriaxone for Treating Community-Acquired Pneumonia in Elderly Patients