Use of colistin in the treatment of multiple-drug-resistant gram-negative infections

Purpose. The use of colistin for the treatment of infections caused by multiple drug-resistant (MDR) gram-negative-microorganisms was studied. Methods. The efficacy of colistin for treating infections caused by MDR gram-negative microorganisms, and the development of renal toxicity were studied in hospitalized adult patients in Spain. Patients treated between January 2001 and October 2001 were included. Results. Over the study period, 71 courses of inhaled colistin, 12 courses of i.v. or intramuscular (i.m.) colistin, and 12 courses of intrathecal colistin were administered to 80 patients. All were infected by MDR organisms: 69 (86%) by Acinetobacter baumannii and 11 (14%) by Pseudomonas aeruginosa. In 41 patients (51%), the episodes were caused by A. baumannii strains exclusively to colistin. The causative organisms were cleared in 92% of the patients from whom posttreatment repeat specimens were obtained. The in-hospital mortality rate was 18% (14 patients). There were no significant changes in mean serum urea or creatinine concentrations in patients receiving i.v. or i.m. therapy. Conclusion. Colistin was used in 80 patients, infected with A. baumannii or P. aeruginosa and appeared to be efficacious and safe.