The pharmacokinetic and pharmacodynamic characteristics of analgesics in children

Abstract

For a large number of medicines, analgesics included, ethical obligations do not permit pharmacological studies in children during pre-registration medicine testing. The very design of such studies is demanding and they are difficult to conduct. The term “children” includes a number of highly diverse groups, from premature neonates to children in puberty and adolescence. Childhood is a period of life in which the complete development and maturation of metabolic paths occurs, including maturation of the metabolic mechanisms responsible for pharmacokinetic and pharmacodynamic processes. The assessment of pain intensity in children presents a number of difficulties, too. Numerous analgesics have a relatively narrow therapeutic width and therefore clinicians are faced with the objective danger of overdosing. Dosage recommendations for specific analgesic agents in children either do not exist or they are based on relatively small clinical studies. Recent multicentric cooperation has made it possible to conduct high quality pharmacodynamic and pharmacokinetic testing for basic analgesics such as acetaminophen, morphine and tramadol.