Equations to estimate prednisone dose using body weight.

BACKGROUND: In the clinical practice, prednisone (PDN) dose in children is often prescribed using the patient weight, despite dose calculation using body surface area (BSA) is assumed to be preferable, because it parallels better with PDN metabolism in human subjects.

METHODS: Calculations based on body weight (W) carry the risk of underdosing, particularly in young children. Conversely, BSA estimation requires knowing the patient height, which is not always available, and more complex calculations.

RESULTS: To overcome these limitations, we have developed linear equations allowing approximating the BSA-based dose using only the patient weight in kilogram. To this end, we have used anthropomorphic data from 754 pediatric patients and have validated the proposed equations with a prospective cohort of 77 children with steroid sensitive nephrotic syndrome. The equation estimating a dose of 60 mg/m2 was [2 × W + 8] and the equation estimating a dose of 40 mg/m2 was [W + 11].

CONCLUSIONS: Both equations performed very well and predicted reliably the BSA-based dose with an average error of 3.4% and 2.2%, respectively.