An evaluation of vancomycin dosing for complicated infections in pediatric patients.

Objective: To determine the incidence with which a vancomycin dosing regimen of 15 mg/kg per dose every 6 hours achieves steady-state trough concentrations of 15 to 20 mg/L in pediatric patients with complicated infections.

Methods: We performed a retrospective chart review for patients admitted to our children's hospital between July 1, 2009, and June 30, 2011. Patients were included if they were between 1 month and 18 years of age, had at least 1 steady-state vancomycin trough obtained, received an initial vancomycin dose of 15 mg/kg per dose every 6 hours, and were being treated for a diagnosis of meningitis, pneumonia, osteomyelitis, bacteremia/sepsis, or endocarditis.

Results: Seventy-four patients were enrolled, mean age of 4.2±3.9 years and weight of 17.0±11.2 kg. Five (6.8%) patients obtained an initial trough of 15 to 20 mg/L. Patients between 1.0 and 5.9 years of age were significantly less likely to achieve an initial trough of 15 to 20 mg/L compared with other age groups evaluated (P=.041). Thirty-four patients with initial subtherapeutic troughs received a dose adjustment and a follow-up vancomycin trough. Of these patients, 15 (44.1%) achieved a trough between 15 and 20 mg/L. The median dose for patients achieving a therapeutic trough at any point during the study was 80 mg/kg per day.

Conclusions: A vancomycin dosing regimen of 15 mg/kg per dose every 6 hours is not likely to achieve a trough concentration of 15 to 20 mg/L in pediatric patients with complicated infections. An initial regimen of 80 mg/kg per day for these patients may be more likely to result in therapeutic steady-state concentrations of vancomycin.