Usefulness of Blood Levels of Antiepileptic Drugs

Abstract

Monitoring the blood levels of anti-epileptic drugs has increased the efficiency and safety of drug therapy in epilepsy. It facilitates individualization of dosage regimen, reveals irregular drug intake, and identifies the responsible agent In intoxicated patients on multiple drug therapy. Blood levels should not be adjusted arbitrarily, however, but used as information in formulating the clinical judgment for each patient. Effective and toxic blood level ranges, as well as the range of levels expected with a given dose (applicable to the majority of patients), are given for the major antiepileptic drugs. These include diphenylhydantoin, phenobarbital, primidone, ethosuximide, and carbamazepine. Indications for ordering blood level determinations are outlined.