Polymyxin B and doxycycline use in patients with multidrug-resistant Acinetobacter baumannii infections in the intensive care unit.
BACKGROUND
Multidrug-resistant Acinetobacter baumannii (MDR-Ab) has emerged as an increasingly problematic cause of hospital-acquired infections in the intensive care unit (ICU). MDR-Ab is resistant to most standard antimicrobials but often retains susceptibility to polymyxin B and doxycycline.


OBJECTIVE
To evaluate the efficacy and toxicity of polymyxin B and doxycycline in the treatment of MDR-Ab infections.


METHODS
A retrospective chart review was conducted between March 2002 and May 2005 in patients who received doxycycline or polymyxin B for treatment of MDR-Ab infections in ICUs within Grady Memorial Hospital, Atlanta, GA.


RESULTS
Thirty-seven patients with MDR-Ab infections were treated with polymyxin B or doxycycline. Median age was 41 years and median ICU length of stay was 18 days prior to acquisition of MDR-Ab. Clinical cure was observed in 22 of 29 (76%) evaluable patients treated with polymyxin B and 2 of 4 (50%) patients treated with doxycycline. In patients with follow-up cultures, microbiological cure was observed in 17 of 21 (81%) patients treated with polymyxin B and 2 of 3 (67%) patients treated with doxycycline. Nephrotoxicity developed in 21% (7 of 33) of patients who received polymyxin B. Neurotoxicity was observed in 2 (6%) patients who received polymyxin B. No adverse reactions were observed with doxycycline. Overall, crude mortality was 27% (9 of 33) and 75% (3 of 4) among those who received polymyxin B and doxycycline, respectively. Three (9%) deaths were attributed to polymyxin B treatment failure, and no deaths were attributed to doxycycline treatment failure.


CONCLUSIONS
Polymyxin B was effectively used to treat a substantial proportion of critically ill patients with MDR-Ab infection and was associated with a similar rate of nephrotoxicity as previously reported. Doxycycline monotherapy was used in a limited number of patients for the treatment of MDR-Ab; further evaluation of its efficacy in larger numbers of patients is warranted.
Holloway
Katherine P
KP
Internal Medicine, Department of Clinical and Administrative Sciences, Mercer University College of Pharmacy and Health Sciences, Atlanta, GA 30341-4155, USA. holloway_kp@mercer.edu
Rouphael
Nadine G
NG
Wells
Jane B
JB
King
Mark D
MD
Blumberg
Henry M
HM
D000151:Acinetobacter Infections / Q000188:drug therapy* / Q000453:epidemiology / Q000401:mortality; D040981:Acinetobacter baumannii / Q000187:drug effects; D000293:Adolescent; D000328:Adult; D000368:Aged; D003428:Cross Infection / Q000188:drug therapy* / Q000453:epidemiology / Q000401:mortality; D004318:Doxycycline / Q000008:administration & dosage*; D024901:Drug Resistance, Multiple, Bacterial; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D007362:Intensive Care Units / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D011112:Polymyxin B / Q000008:administration & dosage* / Q000009:adverse effects; D012189:Retrospective Studies
D011112:Polymyxin B; D004318:Doxycycline