Persistent low concentrations of antiepileptics in a critically ill paediatric patient: an example of multiple potential drug interactions.

A middle childhood boy with epilepsy exhibited persistent low concentrations of valproic acid, lamotrigine and topiramate for over 1 month, primarily due to pharmacokinetic interactions involving fosphenytoin, meropenem and phenobarbital. Awareness of these clinically significant interactions is crucial for ensuring effective seizure control. However, further research is needed to establish optimal evidence-based treatment strategies in complex paediatric cases.