Efficacy and safety of colistin in the treatment of infections caused by multidrug-resistant Pseudomonas aeruginosa in patients with hematologic malignancy: a matched pair analysis.

OBJECTIVE A rise in infections with multidrug-resistant Pseudomonas aeruginosa (MDR-PA) is a significant contributor to increased morbidity and mortality of patients with hematologic malignancies. The aim of this study was to determine the efficacy and safety of colistin (colistimethate sodium) in the treatment of serious infections caused by MDR-PA in these patients. PATIENTS AND METHODS A matched pair analysis of renal function, toxicities, and outcome of 26 patients receiving colistin and control subjects was done. All patients had clinical signs of sepsis; P. aeruginosa was isolated from blood in 69% of patients in colistin group and 84% in control group. Patients treated with colistin received 3 million units every 8 hours for a median duration of 13 days. Additionally, patients received at least two additional antimicrobial or antifungal drugs. RESULTS Resolution of infection was achieved in twenty patients (76.9%) receiving colistin and in 17 (65.4%) control subjects. Mortality rate was 11% in both groups. There was no statistically significant difference in the level of serum creatinine, creatinine clearance, or potassium levels before and after treatment between groups. Only one patient receiving colistin developed de novo renal failure and one displayed transient neurologic toxicity. CONCLUSION Our results suggest that in patients with hematologic malignancies, colistin is effective in treating severe infections caused by MDR-PA while maintaining an acceptable toxicity profile. Prospective randomized studies comparing efficacy and safety of colistin with those of other antipseudomonal drugs are needed.