High-Dose Minocycline Improves Outcomes in Acinetobacter baumannii Group Pneumonia: A Propensity-Weighted Cohort Study with MIC-Based Insights for Breakpoint Revision
Year: 2025
Type: article
Study design: Observational Study
Abstract: INTRODUCTION: Optimal minocycline dosing for Acinetobacter baumannii group pneumonia remains unclear. We assessed the clinical impact of high-dose (HD) versus standard-dose (SD) minocycline and explored the predictive value of susceptibility breakpoints. METHODS: In this multicenter retrospective cohort study, hospitalized adults with AB group pneumonia treated with minocycline were classified into HD (200 mg IV q12h) or SD (100 mg IV q12h or 200 mg IV q24h) groups. Inverse probability of treatment weighting (IPTW) and multivariate logistic regression were applied to adjust for baseline differences. Kaplan-Meier survival and subgroup analyses were performed to evaluate dose-response effects and the utility of different minimum inhibitory concentration (MIC) breakpoints. RESULTS: Among 106 patients (HD: 46; SD: 60), HD therapy was associated with significantly lower in-hospital mortality (28.6% vs. 48.3%; p = 0.046). HD minocycline remained a protective factor in multivariate and IPTW-adjusted models. Long-term (150-day) survival favored HD therapy (log-rank test, p = 0.028). In 28 patients infected with MIC-confirmed isolates, HD therapy consistently trended toward lower mortality across MIC strata. Notably, the pharmacokinetic/pharmacodynamic (PK/PD)-informed breakpoint (≤ 1 µg/ml) better discriminated survival benefit from HD therapy, whereas the Clinical and Laboratory Standards Institute (CLSI) 2024 breakpoint (≤ 4 µg/ml) did not. These findings support dose optimization and align with the revision of CLSI breakpoints in 2025, lowering the minocycline susceptibility breakpoint for Acinetobacter spp. to ≤ 1 µg/ml. CONCLUSIONS: High-dose minocycline significantly improved in-hospital survival for A. baumannii group pneumonia. PK/PD-informed breakpoint may offer greater clinical relevance for guiding minocycline therapy compared to CLSI 2024 breakpoint.
Source: Infectious Diseases and Therapy
Language: English
Subfield: Pharmacology
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $7,400
Awards: G1011789003, Development of Topical Antimicrobial Agent for the Treatment of Drug-Resistant Acinetobacter Baumannii Burn Wound Infection and Application of Rapid Detection System for Burn Wound Biofilms, G3314917546, G3387217061, G4317603126, In Vitro and in Vivo Activities of Cefiderocol against Carbapenem Resistant Acinetobacter Baumannii and Mechanisms of Cefiderocol Resistance in Carbapenem Resistant A. Baumannii, Investigation of the Role of Exopolysaccharide Biosynthesis Gene in Pathogenesis and Innate Immune Response in Hypervirulent Acinetobacter Baumannii Infection, G5462746929, G7147629951, G7533648260, G7546082692, G7708754031, G8365510386
OpenAlex ID: W4416120343