294. Clinical Outcomes in Patients Receiving Tigecycline for Gram-negative Bacteremia
Session: Poster Abstract Session: Antimicrobial Therapy: Clinical Studies
Friday, October 21, 2011
Room: Poster Hall B1
BackgroundTigecycline is FDA approved for a number of conditions but bacteremia has not been specifically addressed.  With its large volume of distribution, serum levels tend to be low, raising concerns regarding its efficacy in bacteremia.  We evaluated our experience with tigecycline therapy in patients with bacteremia.

Methods:  We performed a retrospective study in patients who received tigecycline for bacteremia between January 2008 and February 2011.  Cases were included if they received tigecycline therapy for bacteremia due to Gram-negative bacilli (polymicrobial episodes were included if only Gram-negative bacilli present).  Cases were excluded if they had Gram-positive organisms or only an anaerobic organism.  Cases were matched in a 1:2 fashion with controls for bacterial isolate.   Data collected included patient demographics, microbiology results, antibiotic(s) administered, outcomes and the Charlson Weighted Index of Comorbidity (CWIC).

ResultsTwenty-three cases met inclusion criteria (56.5% female, 74% African-American) and 46 matched controls were identified (54.3% female, 56.5% African-American).  On univariate analysis, patients receiving tigecycline therapy had a higher mortality rate compared to controls (34.8% vs 8.7%, p=0.007).  Cases were more likely to be admitted from an extended care facility (ECF) than controls (73.9% vs. 41.3%, p=0.01). Cases also had a significantly higher CWIC score than controls (7.78±3.5 vs 5.41±2.9, p=0.004) and the average time to administration of an effective antibiotic was longer (65.4 ±49.1 hours vs. 18.2±29.4, p<0.0001).  Logistic regression analysis controlling for admission source, CWIC, tigecycline, and time to administration showed patients were 9.0 times more likely to die if admitted from an ECF (p= 0.048).  None of the other variables included in the model were statistically significant predictors of mortality.

Conclusion:  From logistic regression, the only significant predictor of mortality was admission from an ECF; tigecycline dropped out as a predictor.  Prospective randomized studies will be required to establish definitive evidence of tigecycline’s efficacy in treating patients with Gram-negative bacteremia.


Subject Category: C. Clinical studies of bacterial infections and antibacterials including sexually transmitted diseases and mycobacterial infections (surveys, epidemiology, and clinical trials)

Liza Bautista, MD1, Loveleen Somal, MD1, Pramodini Kale-Pradhan, PharmD2, Karen Hagglund, MS3, Daniel Lalonde4, Paul Padesky4 and Joel Fishbain, MD5, (1)Internal Medicine, St John Hospital and Medical Center, Grosse Pointe Woods, MI, (2)Pharmacy, Eugene Applebaum College of Pharmacy and Health Sciences Wayne State University, Detroit, MI, (3)Graduate Medical Education, St John Hospital and Medical Center, Grosse Pointe Woods, MI, (4)Wayne State University School of Medicine, Detroit, MI, (5)Medicine, St. John Hospital and Medical Center, Grosse Pointe Woods, MI

Disclosures:

L. Bautista, None

L. Somal, None

P. Kale-Pradhan, None

K. Hagglund, None

D. Lalonde, None

P. Padesky, None

J. Fishbain, None

Findings in the abstracts are embargoed until 12:01 a.m. EST Thursday, Oct. 20 with the exception of research findings presented at IDSA press conferences.