Efficacy and Safety of Intravenous Colistin in Very Low Birth Weight Preterm Infants.

BACKGROUND: Given the severity and high mortality of multidrug-resistant Gram-negative bacilli (MDR-GNB) infections, the use of colistin will increase in patients with MDR-GNB infection.

OBJECTIVE: This study aims to assess the efficacy and safety of intravenous colistin in very low birth weight (VLBW; birth weight < 1500 g) preterm infants.

METHODS: We retrospectively analyzed the medical records of patients who received colistin between June 2016 and December 2017. The patients were assigned to two groups: the VLBW group and the non-VLBW group. Both groups were evaluated for response to treatment and adverse effects.

RESULTS: In total, 66 infants who received colistin therapy were included; of these, 28 infants were VLBW. All of our patients received standard colistin treatment of 5 mg/kg per day in three doses and the median duration of colistin treatment was 14 days. No significant differences were observed between the groups with respect to the efficacy of colistin (defined as showing microbiological clearance in control cultures and the absence of mortality during treatment) (89.3 vs 86.8%, p > 0.99). Serum magnesium and potassium levels were significantly lower in the VLBW group than in the non-VLBW group during colistin therapy (magnesium, 1.30 vs 1.70 mg/dL, p < 0.001; potassium, 3.6 vs 4.6 mEq/L, p < 0.001). Acute kidney injury was observed in four infants in the VLBW group and one in the non-VLBW group, without significant differences (p = 0.15).

CONCLUSIONS: Colistin administration appears to be efficacious in VLBW infants; however, renal function tests and serum electrolytes should be monitored more closely in these infants during treatment.