The use of newly marketed drugs in children and adolescents prescribed in general practice

This study determined the licensed and 'off label' (outside the terms of th e licence) use of newly marketed medicines in children (2-11 years) and ado lescents (12-17 years), by general practitioners in England. In addition, t he incidence rates during the first month of therapy (ID1) for three advers e events, in these groups were compared with those of adults (greater than or equal to 18 years). The use of these drugs was monitored in 63 individua l prescription-event monitoring (PM) studies, conducted to monitor the safe ty of these medicines. Patients and drug exposures were identified from dis pensed prescriptions. Outcome data (events and demographic information) wer e obtained from questionnaires. Although only six of these 63 drugs were li censed for use in children, 44 of the 63 drugs were used to treat children. For the majority of the drugs there was no specific reference to adolescen ts in the data sheets therefore it has been assumed that the drugs were lic ensed for those aged greater than or equal to 12 years unless specified oth erwise; 55 have been taken as licensed for use in adolescents. Over 690,000 patients were included in the 63 PEM studies, 9081 (1.3%) of these were ch ildren and 15,256 (2.2%) were adolescents, 78% of the 9081 children and 93% of the 15,256 adolescents were treated with 'licensed' drugs. There was a significant difference in the incidence rate for rash and nausea/vomiting, two adverse events commonly reported during treatment with lamotrigine, bet ween children and adolescents compared to adults. This survey has shown tha t although only a small proportion (10%) of newly marketed drugs were licen sed for use in children the majority of children (78%) were treated with th ese licensed products but 22% of children received drugs 'off label' during the first few years that the drug was marketed and a small number of child ren and adolescents were given drugs contraindicated in these age ranges. C opyright (C) 1999 John Wiley & Sons, Ltd.