Serum bilirubin levels with antiepileptic drugs

The incidence of reduced bilirubin levels in 168 outpatients with epilepsy, compared with levels in 69 controls, has been investigated. Highly significant (p less than 0.001) reductions in average bilirubin levels were noted for carbamazepine (CBZ), phenytoin (PHT), phenobarbital (PB), and multiple drug groups. A marginally significant (p less than 0.05) reduction in bilirubin levels occurred in patients treated with valproate (VPA) which, unlike the other drugs, has not been shown to induce hepatic enzymes.