Effectiveness and safety of colistin for the treatment of multidrug-resistant Pseudomonas aeruginosa infections.
OBJECTIVE
To describe the clinical and microbiological outcomes of patients infected with multidrug-resistant Pseudomonas aeruginosa (MDRP) treated with colistin (colistimethate sodium) and the adverse events observed with this treatment.


METHODS
Retrospective study of MDRP infections treated with colistin from 1997 to 2006.


RESULTS
121 episodes were identified. The median daily intravenous dose was 240 mg/day; 28.9% of patients received intravenous and nebulized colistin. Clinical outcome was favorable in ten cases of bacteremia (62.5%, n = 16), 43 cases of bronchial infection (72.9%, n = 59), 13 cases of pneumonia (65%, n = 20), 11 cases of urinary infection (84.6%, n = 13), eight cases of skin and soft tissues (72.7%, n = 11), and in the one case of arthritis and one case of otitis. Eradication was achieved in 31 (34.8%) of the 89 patients with available bacteriologic data. Factors associated with bacteriological failure were smoking, chronic obstructive pulmonary disease (COPD), and previous infection with P. aeruginosa. Nephrotoxicity occurred in ten cases (8.3%), with the associated factors being previous chronic renal insufficiency, diabetes mellitus, and aminoglycoside use. Crude mortality was 16.5%, and related MDRP was 12.4%, and was higher in patients with pneumonia or bacteremia (36.1%) than in other types of infections (8.2%).


CONCLUSIONS
Colistin is a safe option for the treatment of MDRP infections, with acceptable clinical outcomes. However, bacteriological eradication is difficult to achieve, especially in COPD patients.
Montero
M
M
Dept. of Internal Medicine and Infectious Diseases, Hospital del Mar, Autonomous University of Barcelona, Barcelona, Spain. 95422@imas.imim.es
Horcajada
J P
JP
Sorlí
L
L
Alvarez-Lerma
F
F
Grau
S
S
Riu
M
M
Sala
M
M
Knobel
H
H
D000280:Administration, Inhalation; D000368:Aged; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000009:adverse effects* / Q000627:therapeutic use*; D003091:Colistin / Q000008:administration & dosage / Q000009:adverse effects* / Q000627:therapeutic use*; D024901:Drug Resistance, Multiple, Bacterial; D005260:Female; D006801:Humans; D007275:Injections, Intravenous; D007674:Kidney Diseases / Q000139:chemically induced; D008297:Male; D008875:Middle Aged; D011552:Pseudomonas Infections / Q000188:drug therapy* / Q000382:microbiology / Q000401:mortality; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000302:isolation & purification; D012189:Retrospective Studies; D016896:Treatment Outcome
D000900:Anti-Bacterial Agents; D003091:Colistin