Medicines management in children and young people: pharmacokinetics, drug calculations and off-label drug use.

Medicines management in children and young people presents specific challenges because children differ from adults in their response to medicines. The way in which medicines work inside the human body, or pharmacokinetics, varies according to age and stage of development. Accurate drug calculations for a child rely on the careful consideration of a series of factors, such as weight and height, pharmacokinetics and drug characteristics. This article focuses on three fundamental aspects: pharmacokinetics, drug calculations, and unlicensed and off-label drug use.