Colistin is one of the last resort antibiotic options for resistant gram-negative pathogens. Renal injury is the most common side effect of colistin. Characteristics of nephrotoxicity are well described in adults. However, this data is sparse in children.

In this study we evaluated the incidence, severity, time course and risk factors of colistin nephrotoxicity in a pediatric population.

In a prospective study over a 9-month period, children who received intravenous colistin for at least 48 h were evaluated for renal side effect by utilizing Risk-Injury-Failure-Loss-End Stage Kidney Disease (RIFLE) criteria. Children receiving renal replacement therapy (RRT) or received a repeated course of colistin were excluded.

Thirty-seven children were included. Median age of participants was 4.5 months. Overall, 48.6% of the cases developed AKI and consisted 56% in the Risk, 33% in the Injury and 11% in the Failure categories of RIFLE criteria. AKI was reversible while colistin continued and no one required RRT. Mean ± SD time to AKI development was 10.94 ± 7.51 days. Multivariate logistic regression analysis demonstrated that total cumulative dose of colistin was an independent predictor of nephrotoxicity (standardized ß = 1.024, P = 0.034).

AKI is a common side effect of colistin therapy in critically ill children developing in nearly half of recipients. However, with the dosage range utilized in this study, in the majority of children, renal injury seemed to be mild to moderate in nature. Given the limited treatment options available in critically ill children with resistant gram-negative pathogens, colistin remains a marvelous therapeutic option. Further studies are required to fully elucidate the risk factors and clinical pictures of colistin-induced nephrotoxicity.