Pharmacological Variability in Children- When is Monitoring Needed?

Children constitute a vulnerable group of patients of special importance regarding pharmacological therapy. They differ considerably from the adult population due to rapid physiological changes during infancy and early childhood. These changes affect all pharmacokinetic processes, from absorption and distribution, to metabolism and excretion [1-3], as well as target organs for pharmacotherapy and therefore pharmacodynamics. Newly approved drugs are often scarcely studied in children. A narrow spectrum and unpredictable relationships between efficacy and tolerability for many drugs call for careful clinical considerations, where antiepileptic drugs will be used as examples in this text. Focus on pharmacological variability and monitoring of longterm drug therapy in children is therefore needed.