Effect of Different Colistin Doses on Clinical Outcome of Pediatric Cancer Patients With Gram Negative Infections

Inclusion Criteria: 1. Age between one year and 18 years 2. All paediatric cancer patients who are prescribed intravenous colistin due to: * Sepsis due to MDR or minimally susceptible gram-negative bacteria * History of MDR gram-negative infection or sepsis due to organisms sensitive to colistin. * Culture result consistent with MDR gram negative for this febrile neutropenic episode. * Patient in sepsis and colistin was administered empirically to increase antibiotic coverage. Exclusion Criteria: 1. Age less than one year or over 18 years 2. Patients with renal impairment 3. Colistin use less than 72 hours