Clinical experience with tigecycline against gram-negative infections

Purpose: In vitro studies have shown efficacy of tigecycline in the eradication of multidrug-resistant (MDR) gram-negative organisms including Extended-spectrum b-lactamases-producing (ESBL) and carbapenem-resistant Enterobacteriaceae (CRE).  Unfortunately, there is a lack of clinical data supporting the use of tigecycline for serious infections caused by these organisms.  Therefore, we sought out to evaluate the efficacy and prevalence of tigecycline for the treatment of MDR gram-negative infections in a private community hospital. 

Methods: We conducted a retrospective cohort study of patients who received tigecycline for gram-negative infections from January 1 to December 31, 2010 at Piedmont Hospital, Atlanta, GA. Clinical and microbiological characteristics of all patients who were treated with tigecycline for MDR gram-negative infections were reviewed.  Patients who received less than 3 doses of tigecycline were excluded.  All statistical analyses were performed using standard bivariate and multivariate techniques to determine the association of treatment success with mono vs. combination therapy and causative microorganism. 

Results:  Of the 131 patients evaluated, 54 (41.2%) received tigecycline for FDA-approved vs. 77 (58.8%) non FDA-approved use (p > 0.05).  There was not statistically significant difference in clinical outcomes in susceptible vs. ESBL/CRE pathogens groups.  There were 30 (22.9%) patients who received monotherapy vs. 101 (77.1%) of patients who received combination therapy which was statistically significant in monotherapy group (p<0.05). 

Conclusions:  Tigecycline has established in vitro activity against a wide array of gram-positive and gram-negative strains of bacteria. Our study supports the use of tigecycline monotherapy for severe infections caused by MDR gram-negative organisms.  The role of tigecycline is warranted for further investigation.