Za veliki broj lijekova, pa tako i za analgetike, iz etičkih se razloga ne provode farmakološke studije u djece tijekom preregistracijskog ispitivanja lijeka. Dizajniranje ovakvih studija vrlo je zahtjevno i teško provedivo. Pojam „djeca“ uključuje vrlo heterogenu skupinu, od prematurne novorođenčadi do puberteta i adolescencije. To je razdoblje života u kojem se odvija kompletan razvoj i sazrijevanje metaboličkih mehanizama odgovornih za procese farmakodinamike i farmakokinetike. Procjena intenziteta boli u djece opterećena je brojnim teškoćama. Mnogi analgetici imaju relativno malu terapijsku širinu i kliničari su suočeni s realnom opasnošću od predoziranja. Preporuke za doziranje pojedinog analgetika u djece često ne postoje ili su bazirane na relativno malim kliničkim studijama. Multicentrična suradnja je u novije vrijeme omogućila pojavu kvalitetnih farmakodinamskih i farmakokinetskih ispitivanja za osnovne analgetike kao što su paracetamol, tramadol i morfin.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 top conduct high quality pharmacodynamic and pharmacokinetic testing for basic analgesics such as acetaminophen, morphine and tramadol
