CYP2D6 acts on 25% of all prescription drugs.  Approximately 4-7% of the population has a slow acting form of this enzyme and 3% a super-fast acting form. About 35% of the population are carriers of a non-functional CYP2D6 allele, which especially elevates the risk of adverse drug events (ADEs) when these individuals are taking multiple drugs.
Drugs that CYP2D6 metabolizes include selective serotonin reuptake inhibitors (SSRI), tricyclic antidepressants (TCA), beta-blockers, opiates, neuroleptics, antiarrhythmics, and a variety of toxic plant substances. Specific notable drugs include fluoxetine (Prozac®), sertraline (Zoloft®), paroxetine (Paxil®), venlafaxine (Effexor®), hydrocodone (Zohydro ER®), amitriptyline (Elavil®), loratadine (Claritin®), cyclobenzaprine (Armix®), haloperidol (Haldol®), metoprolol (Lopressor®), propafenone (Rythmol®), cimetidine (Tagamet®), tamoxifen (Nolvadex®), and the over-the-counter diphenhydramine drugs, fexofenadine (Allegra®). CYP2D6 is also responsible for activating the prodrugs codeine and other opioids into their active forms. The analgesic activity of the drugs is therefore reduced or absent in CYP2D6 poor metabolizers. Refer to CYP2D6 drug list for substrates, inhibitors, and inducers. 
Genelex offers improved detection rates using an extended Cytochrome P450 2D6 DNA mutation panel. This CYP2D6 test identifies 25 variants of the more common alleles (*2,*2A,*3-*12,*14,*15,*17,*19,*20,*21,*29,*30,*35,*36,*41,*56,*109), gene deletions, gene duplications and gene rearrangements in PCR-multiplex format, providing increased sensitivity and quality performance. Copy number and gene re-arrangement determinations may not always be determined. This CYP2D6 Mutation Detection Panel is the most extensive on the market and covers over 93-97% of poor metabolizer phenotypes. Analytical specificity and sensitivity for detection of these mutations are >99%.
Indication for CYP2D6 Testing
For individuals with a personal or family history of adverse drug reactions to medications metabolized by CYP2D6. Confirm the presence of genotypes that affect the metabolism of drugs such as tamoxifen (Nolvadex®) that are metabolized by CYP2D6.
Check with your insurance provider to determine if CYP2D6 testing and genotyping is covered. CPT Code is 81227 (provided as guidance only).
Click here to order testing supplies or call Client Services at 800-837–8362.
- Buccal Swabs: 4 sterile buccal swabs
- Blood: 5-10cc whole blood lavender-top EDTA or yellow-top ACD-A tubes
- Turnaround Time: 10 business days, faster turnaround available for clinical trials