Predictors of Clinical Success with High-Dose Tigecycline: A Retrospective Cohort Study

Background: Tigecycline is sometimes used as a last resort for infections caused by multidrug-resistant (MDR) and extensively drug-resistant (XDR) Gram-negative bacteria. Due to the increased demand for using tigecycline and the limited available data about the efficacy and safety of high doses (HD) of tigecycline, this study aimed to evaluate the potential factors associated with clinical success in hospitalized patients receiving HD tigecycline. Methods: This was a retrospective, multicentered cohort study. Data were acquired from patients’ medical records from 2017 to 2019. We included adult patients (≥18 years old) who received tigecycline as monotherapy or in combination for at least 3 days with a microbiologically documented infection. Results: Out of 74 included patients, 17 (23%) had clinical success. Clinical success was significantly associated with younger age (OR = 0.96, 95% CI, 0.93–0.99; P = 0.009), hospitalization in the medical ward (OR = 0.04, 95% CI, 0.01-0.32; P < 0.001), lower Charlson Comorbidity Index (CCI) score (OR = 0.70, 95% CI, 0.55–0.88; P = 0.005), and proof of bacterial eradication in follow up cultures (OR = 67.20; 95% CI 6.90–654.55; P <0.001). Other factors, such as number of antibiotics, duration of tigecycline therapy, type of isolated pathogen, and their susceptibility to tigecycline, were not significantly associated with the clinical outcomes. Conclusion: The clinical success rate was low with tigecycline therapy. Younger age, lower CCI score, hospitalization in the medical ward, and bacterial eradication were significantly associated with clinical success with HD tigecycline. Large prospective studies are warranted to confirm these findings.