Research Article
Polymyxin E Combination Regimens Versus Monotherapy for The Treatment of Pandrug-Resistant Acinetobacter Baumannii Pneumonia: Efficacy and Safety
Rui Li¹, Kang-ming Yi¹, Chun-huan He¹, Si-li Xie1,*
1Department of Pharmacy, The First Affiliated Hospital of Jinan University, North-Gulf Hospital and People’s Hospital of Lianjiang, Lianjiang, Guangdong 524400, China.
*, Correspondence
Rui Li, Department of Pharmacy, The First Affiliated Hospital of Jinan University, North-Gulf Hospital and People’s Hospital of Lianjiang, Lianjiang, Guangdong 524400, China. Email: 262833109@qq.com.
Received: April 12, 2026; Accepted: July 28, 2026; Published online: August 2, 2026.
Cite this paper: Rui Li, Kang-ming Yi, Chun-huan He, Si-li Xie. (2026) Polymyxin E Combination Regimens Versus Monotherapy for The Treatment of Pandrug-Resistant Acinetobacter Baumannii Pneumonia: Efficacy and Safety. Global Journal of Medicine, 6(1):10-18. http://naturescholars.com/gjm.060102. https://doi.org/10.46633/gjm.060102.
Copyright© 2026 by Scholars Publishing, LLC.
Abstract
Objective: To compare the clinical efficacy and safety of polymyxin E monotherapy versus combination regimens in the treatment of pandrug-resistant Acinetobacter baumannii (PDRAB) pneumonia. Methods: A retrospective study was conducted in which 26 patients with PDRAB pneumonia admitted to a tertiary hospital between July 2023 and June 2024 were divided according to their treatment regimens into a monotherapy group (13 cases, polymyxin E alone) and a combination-therapy group (13 cases, polymyxin E plus cefoperazone–sulbactam or tigecycline). Changes in infection markers including body temperature, white blood cell (WBC) count, procalcitonin (PCT), and C-reactive protein (CRP) before and after treatment were compared, and clinical efficacy was evaluated. Categorical variables were compared using Fisher’s exact test, and continuous variables were compared using independent-samples t-tests or Mann–Whitney U tests as appropriate. A post-hoc power analysis was performed. Results: The overall response rate in the combination group was 76.9% (10/13) compared with 61.5% (8/13) in the monotherapy group (Fisher’s exact test, P=0.673); the difference was not statistically significant. Decreases in WBC, PCT, and CRP were significantly greater in the combination group than in the monotherapy group (P=0.002, P=0.003, and P=0.002, respectively). The post-hoc power for the response-rate comparison was 13.6%, indicating that the study was underpowered to detect a difference of this magnitude. Conclusion: Polymyxin E–based combination therapy showed greater reductions in inflammatory markers compared with monotherapy, although the difference in clinical response rate did not reach statistical significance. These preliminary findings are hypothesis-generating and warrant confirmation in larger, prospective, randomized studies. No significant increase in adverse events was observed in this small sample.
Key words: Polymyxin E; Acinetobacter baumannii; Pneumonia; Cefoperazone–sulbactam; Tigecycline.