What are the most useful enzymes to test genetically?
• CYP2D6 (cytochrome P450 2D6) is the best studied of the DMEs (drug metabolizing enzymes) and acts on one quarter of all prescription drugs. Approximately ten percent of the population have a slow acting form of this enzyme and five percent a super-fast acting form. Drugs that CYP2D6 are thought to inactivate include Prozac, Zoloft, Paxil, Effexor,hydrocodone , amitriptyline, Claritin, cyclobenzaprine, Haldol, metoprolol, Rythmol, Tagamet, tamoxifen, and the over-the-counter diphenylhydramine drugs, Allegra, Dytuss and Tusstat. • CYP2C9 (cytochrome P450 2C9) is the primary route of metabolism for Coumadin (warfarin), Amaryl, isoniazid, sulfa and ibuprofen. Clinical studies suggest that the use of genetic testing may be especially helpful with warfarin administration. Other drugs that are thought to be metabolized by 2C9 include, amitriptyline, Dilantin, Hyzaar, THC (tetrahydrocannabinol), naproxen and Viagra. • CYP2C19 (cytochrome P450 2C19) is associated with the metabolism of cariso
