Clinical utility of unbound antiepileptic drug blood levels in the management of epilepsy.

ABSTRACT

We tabulated all unbound and total antiepileptic blood levels collected in 13 months. According to strict criteria, 24% of phenytoin and 15% of valproate unbound blood levels but none of the carbamazepine unbound levels had clinical significance in the management of seizures or side effects. These data support frequent use of unbound phenytoin or valproate blood levels in the management of epilepsy.