RESUMO
Medication use in children represents 15-20% of total drug sales. More than 50% of children receive at least one prescription medication a year. Despite this, few drugs have a paediatric formulation available. Furthermore, 80% of paediatric prescriptions are considered off-label. Off-label use is defined as the use of products that differ in dose, indication or route of administration from the one established in the summary of product characteristics. Off-label use is associated with an increased risk of adverse drug reactions, including therapeutic failure. The US Food and Drug Administration and the European Medicines Agency have made changes to regulations to incentivize the development of paediatric formulations. Novel paediatric formulations can ease drug administration, reducing medication errors, increasing dosing acceptability, medication adherence and improve safety. Two routes for paediatric drug approval are available, the traditional, requiring clinical trials and the formulation bridging path, where these formulations need to demonstrate equivalence with the existing adult formulations. New formulations seeking regulatory approval require bioequivalence studies, but the regulatory framework, which states that bioequivalence data are obtained from adults and then extrapolated to children, may be disregarding important physiological differences between these two populations of patients. It is important to ensure that drugs for children have been appropriately studied and are properly manufactured for them. Adequately designed studies will provide data that will improve our understanding of how drug disposition differs between adults and children and will pave the way for children to get the best possible treatment.