300. Clinical outcomes and emergent renal dysfunction associated with colistin use over four years
Session: Poster Abstract Session: Antimicrobial Therapy: Clinical Studies
Friday, October 21, 2011
Room: Poster Hall B1
Background:  Colistin is increasingly prescribed for the treatment of multi-drug resistant gram negative infections.  We describe the outcomes associated with colistin use at our institution over a four-year period.

Methods:  A retrospective chart review of patients who received colistin from 2004 to 2007 was conducted.  The primary outcome was clinical success, defined as cure or improvement.  Clinical failure was defined as worsening or death.  Patients who received at least three days of therapy were analyzed in the primary outcome.  The secondary outcome was development of renal dysfunction on colistin, defined as an increase in serum creatinine of 50% or more during therapy.  Patients who were not on dialysis and received at least one dose of colistin were evaluated.  Characteristics of patients and of the therapy were analyzed by logistic regression separately for association with clinical success and the emergence of renal dysfunction.

Results:  There were 146 patients evaluated for clinical outcome, while 167 patients were eligible for assessment of renal dysfunction.  Pneumonia and bacteremia accounted for the majority of infections.  Clinical success was observed in 76/146 (52.1%) patients.

Outcomes for Patients Receiving At Least Three Days of Colistin (n = 146)


Clinical Success

Clinical Failure

p value

Age (mean)



< 0.001

Length of stay (days)




Hospital day colistin started








Charlson Index




Days of therapy




Dose (mg/kg/day)




On multivariate analysis, age, APACHE II and days of therapy remained statistically significantly associated with outcome.

Of 167 evaluable patients, 77 (46.1%) experienced renal dysfunction on colistin.  On multivariate analysis, dose (mg/kg/day) and receipt of additional nephrotoxin(s) increased the risk of developing renal dysfunction.

Conclusion:  In this critically ill population, colistin use resulted in clinical success in a small majority of patients.  Renal dysfunction occurred frequently and was associated with higher colistin doses and receipt of nephrotoxins.

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

Julie Collins, M.D., Section of Infectious Diseases, Temple Univ. Hosp., Philadelphia, PA, Kevin Haynes, Pharm.D, M.S.C.E., Department of Biostatistics and Epidemiology, Univ. of Pennsylvania, School of Medicine, Philadelphia, PA and Jason Gallagher, Pharm.D., B.C.P.S., School of Pharmacy, Temple Univ., Philadelphia, PA


J. Collins, None

K. Haynes, None

J. Gallagher, Pfizer: Scientific Advisor, Consulting fee
Merck: Grant Investigator, Grant recipient
Astellas: Speaker's Bureau, Speaker honorarium

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.