Adverse Drug Reactions in Children

Abstract

e105 Results: Factor VIII activity following administration of moroctocog alfa to haemophilia A patients was described with a 2-compartment disposition model including a baseline model. Covariates identified as predictors of the disposition were body size, age, inhibitors, race and analytical assay. Following the administration of plasma-derived factor IX to haemophilia B patients the activity was best characterised with a 3-compartment model with a baseline model, in which disposition parameters were related to body weight. It was found that accurate individual doses of factor IX could be obtained with few samples (2-3), provided that timing of sampling and data below the lower limit of quantification were handled appropriately. When choosing a sampling schedule, practicality has to be weighed against what is required for reasonable accuracy and precision in dose predictions. Conclusions: Our results were in agreement with previous publications but added quantitative information concerning the influence of low age and inhibitors on factor VIII disposition. The exploration of sampling schedules for model-based dose individualisation identified important factors to consider such at appropriate methodology and sufficient and practical sampling schedules.