Multidrug-resistant Acinetobacter baumannii pneumonia in clinical therapy: A systematic review and network meta-analysis on effectiveness and safety of different antibiotic combination regimens.

OBJECTIVE

To evaluate the effectiveness and safety of different antibiotic regimens for multidrug-resistant Acinetobacter baumannii (MDRAB) pneumonia using a network meta-analysis (NMA).

METHODS

PubMed, Embase, and the Cochrane Library were searched from inception to January 2026. Randomized controlled trials and cohort studies were eligible for the systematic review; only cohort studies with MDRAB pneumonia and a connected treatment network were included in the NMA. The review was registered in PROSPERO (CRD42023481794). Two reviewers independently screened studies, extracted data, and assessed risk of bias using RoB 2 for randomized trials and the Newcastle-Ottawa Scale for observational studies. A frequentist random-effects NMA estimated odds ratios (ORs) with 95% confidence intervals and P-scores for treatment ranking. Short-term mortality, clinical response, microbiological eradication, nephrotoxicity, and neurotoxicity were analysed.

RESULTS

Seventeen cohort studies including 1420 patients were synthesized. Colistin-based inhalation regimens ranked highest for clinical response, whereas tigecycline-based regimens were consistently less favorable. Sulbactam-based and colistin-based regimens showed similar effectiveness for clinical response and microbiological eradication. Overall, no statistically significant differences in mortality were observed between sulbactam-based and colistin-based regimens; however, the colistin-sulbactam combination regimen showed a tendency toward higher mortality than other colistin-based regimens. Similarly, the results for nephrotoxicity were comparable among the different regimens.

CONCLUSIONS

Sulbactam-based regimens appear to offer effectiveness comparable to colistin-based regimens for MDRAB pneumonia, while tigecycline-based regimens may require higher doses to achieve optimal benefit. These findings can inform regimen selection where newer agents are unavailable.