Generic name Brand name Metabolism
haloperidol Haldol CYP2D6/3A4
perphenazine Trilafon CYP2D6
chlorpromazine Thorazine CYP2D6, GT1A4
thioridazine Mellaril CYP2D6
thiothixene Navane CYP2D6
trifluoperazine Stelazine&nbsp
Atypical antipsychotics
clozapine Clozaril CYP1A2/3A4, GT1A3/4
risperidone Risperdal CYP2D6
olanzapine Zyprexa CYP1A2
quetiapine Seroquel CYP3A

CYP = cytochrome P-450; GT = glucuronosyltransferase.

Adapted from: Koppel BS. Contribution of drugs and drug interactions (prescribed, over the counter, and illicit) to seizures and epilepsy. In: Ettinger AB and Devinsky O, eds. Managing epilepsy and co-existing disorders. Boston: Butterworth-Heinemann; 2002;163.
With permission from Elsevier (

Authored By: 
BS Koppel
Reviewed By: 
Steven C. Schachter MD
Monday, March 1, 2004