Characteristics and outcomes of patients treated with tigecycline for MDR gram-negative infections: a retrospective cohort study

Introduction: Multidrug-resistant (MDR) gram-negative pathogens pose a major therapeutic challenge, particularly in settings with limited antimicrobial options. Tigecycline is frequently used as salvage therapy. However, evidence regarding the optimal tigecycline regimen, whether used as monotherapy or in combination, remains uncertain. This study aimed to describe the characteristics, clinical, and microbiological outcomes of these cases. Methods: . Patients were categorized into tigecycline monotherapy or combination therapy groups. The primary outcomes were clinical success and 30-day mortality. Multivariable logistic regression was used to identify predictors of outcomes. A sensitivity analysis excluding bloodstream and urinary tract infections was performed due to pharmacokinetic limitations of tigecycline. Results: = 0.001), and 30-day mortality was 26.1%. After adjustment, tigecycline monotherapy was not independently associated with clinical success or mortality. Sensitivity analyses excluding bloodstream and urinary tract infections showed consistent results. Conclusion: In this real-world cohort of severely ill patients with MDR gram-negative infections, no outcome advantage was observed with tigecycline combination therapy after adjustment. Clinical outcomes were primarily driven by illness severity and infection characteristics rather than treatment strategy.