In this paper, we present a comprehensive bioethical and regulatory analysis of the use of drug therapy in children with oncological, rheumatological, cardiological and psychiatric diseases in the Russian Federation based on official Instructions for Medical Use and the latest clinical recommendations. This paper focuses on significant contradictions between clinical recommendations and drug registration documents registered in the State Register of Medicines of Russia. Insufficient scientific data on safety and effectiveness of medicines among children deserve particular attention as it results in serious therapy restrictions worsened by regulatory and legal barriers for pediatricians. The study is focused on medications for treatment of follicular lymphoma, systemic lupus erythematosus, schizophrenia and familial hypercholesterolemia, with an emphasis on age restrictions and contraindications.