Utilization of colistin for treatment of multidrug-resistant Pseudomonas aeruginosa.

BACKGROUND

Colistin is uncommonly used in clinical practice; however, the emergence of multidrug-resistant organisms has rekindled interest in this potentially toxic therapeutic option. The present study describes the authors' experience with colistin in the management of patients who were infected with metallo-beta-lactamase (MBL)-producing Pseudomonas aeruginosa within the Calgary Health Region (Calgary, Alberta).

METHOD

Adult patients who received colistimethate sodium (colistin) between January 2000 and December 2005 were identified via pharmacy records, and their charts were reviewed retrospectively. Patients with cystic fibrosis were excluded. Patient demographics, clinical course and relevant laboratory data were extracted.

RESULTS

Twenty-eight courses of colistin were received by 22 patients. The majority of these treatments were directed at MBL-producing Pseudomonas. One-half of the patients received nebulized colistin. Intravenous (IV) colistin was administered to 12 patients for a mean +/- SD of 14.7+/-13.8 days (range 3.7 to 46 days). The highest IV dose used was 125 mg every 6 h or 6 mg/kg/day. Eight of 12 patients (67%) treated with IV colistin responded either fully or partially. Two patients received IV colistin as outpatients. Adverse effects considered to be due to colistin included drug fever, nephrotoxicity and neurotoxicity. Five of nine patients (56%) who had complete data available for evaluation had at least a doubling of creatinine levels from baseline.

CONCLUSION

Patients in the present study received both IV and nebulized colistin for multidrug-resistant P aeruginosa. The use of IV colistin was associated with a favourable response, but mild nephrotoxicity occurred in two-third of patients. It was concluded that colistin may be a useful drug when choices are limited.