Katip W, et al. - This study aimed at evaluating the effect of the loading dose of colistin for treatment of extensively drug-resistant Acinetobacter baumannii (XDR-AB) in cancer patients. Authors realized that administration of colistin loading resulted in no significant increase in clinical response, microbiological response or mortality rate compared to non-loading dose in cancer patients with XDR-AB-related infections. However, there appeared significantly higher nephrotoxicity when patients were administered loading dose colistin.

Methods

• Authors conducted a retrospective cohort study of cancer patients who received either a loading or non-loading dose of colistin for treatment of XDR-AB.
• For each group, they documented the clinical response, bacteriological eradication and serum creatinine.
• They used logistic regression to assess the effects of therapy on each of the three aforementioned outcomes.

Results

• Authors recruited 102 patients diagnosed with XDR-AB infections between January 2012 and December 2015.
• A loading dose of colistin was administered to only 75 patients.
• No marked clinical and microbiological response was evident in patients in the loading dose group or patients in the non-loading dose group.
• However, nephrotoxicity developed in 38 (50.67%) patients in the loading dose group and 6 (22.22%) patients in the non-loading dose group according to the RIFLE criteria (p = 0.013).
• As per multivariate logistic regression analysis, independent predictors of clinical response included Charlson score ≥4 and duration of colistin treatment ≥10 days.
• In this study, septic shock seemed associated with both poor clinical and microbiological response.
• Independent predictors for nephrotoxicity included loading dose colistin and patient’s age ≥60 years.