Abstract Background Pediatric pharmacokinetics (PK) differ from adults due to their unique developmental stages and physiological immaturity. However, the lack of pediatric‐approved drugs often necessitates the off‐label use of adult‐approved medications, thereby burdening the healthcare providers with dosing decisions and leaving pediatric efficacy and safety uncertain. We defined pediatric off‐label use as the prescription to pediatric patients of medications for which only dosages for adults are specified in the package insert and quantified its prevalence in Japan. Methods Data from the National Database (NDB) sampling dataset (July and October 2022 and January and April 2023) on oral/injectable medications prescribed to children aged 0–14 years were analyzed to assess off‐label pediatric use. Cross‐tabulations were conducted to examine pediatric indication categories, as specified in package inserts, across different pediatric age groups and Anatomical Therapeutic Chemical (ATC) classifications. Due to the higher prevalence of off‐label use among inpatients, detailed analyses quantified the proportion of pediatric off‐label users by ATC level 2 (≥150 users) and identified specific active substances used off‐label in neonates/infants (≥50 users). Results Overall, pediatric off‐label use was 24% in inpatients and 14% in outpatients. Notable variability was observed across the ATC classifications. Specifically, the off‐label use was 1.9% for antibacterials (J01), 32.5% for antineoplastics (L01), and 65.5% for diuretics (C03). Conclusions This NDB‐based study offers foundational nationwide data on pediatric off‐label use, revealing delays in pediatric medication development and inconsistencies in package inserts that vary across age groups and therapeutic areas, insights that can help improve safety and optimize pediatric healthcare delivery.
Aino et al. (Thu,) studied this question.