The benefits of antiepileptic drug (AED) blood level monitoring to complement clinical management of people with epilepsy

IntroductionSome argue that there is no evidence to support the use of antiepileptic drug (AED) blood level monitoring when treating people with epilepsy (PWE). This paper identifies how AED monitoring can be invaluable in such treatment.Specific examples

• (i)Compliance: Antiepileptic drug blood levels often confirm noncompliance rather than adequate seizure control, confirming subtherapeutic levels in PWE attending hospitals due to seizures. Routine monitoring of AED levels may prevent breakthrough seizures by identifying noncompliance and instituting heightened compliance measures before experiencing breakthrough seizures without modifying dosages. For PWE attending hospitals due to seizures, loading with the AED shown to be subtherapeutic may be all that is required.
• (ii)Cluster seizures and status epilepticus: When using long-acting AEDs to complement benzodiazepines, blood level monitoring confirms that an adequate dosage was given and, if not, a further bolus can be administered with further monitoring. This is particularly useful when using rectal administration of AEDs.
• (iii)Polypharmacy: Polypharmacy provokes drug interactions in which case AED monitoring helps in differentiating adequate dosing, offending AED with toxicity and free level measuring benefits when total levels are unhelpful.
• (iv)Generic substitution: Generic AEDs can fluctuate considerably from a parent compound, and even a parent compound, sourced from an alternative supplier, may have altered bioavailability for which blood level monitoring is very useful.

ConclusionsWhile therapeutic blood level monitoring is not a substitute for good clinical judgment, it offers a valuable adjunct to patient care.