CYP2B6 Genotyping

CYP2B6 metabolizes about 10 percent of all drugs. There is strong evidence that certain variants, also known as alleles, of this gene can affect efavirenz, bupropion and methadone metabolism. Patients who are initiating these therapies, or have a history of adverse effects or treatment failure should be considered for CYP2B6 genotyping. CYP2B6 is primarily expressed in the liver and involved in the first-pass metabolism of ingested drugs. It has also been detected in several tissues outside the liver, including the brain, kidney and intestine.


Indications for Testing

Patients with a personal or family history of adverse drug reactions or treatment failures to efavirenz, bupropion, methadone or other medications metabolized by CYP2B6 are good candidates for testing. CYP2B6 genoytping may also be useful to confirm or rule out the presence of genetic variation that affects the metabolism of drugs metabolized by this gene.

Testing can potentially allow prescribers to optimize efavirenz therapy, better predict bupropion efficacy and identify methadone users at increased risk of developing QTc prolongation.


Insurance Coverage

CYP2B6 testing is not currently covered by Medicare. Private insurance coverage varies by insurance company. The CPT code for CYP2B6 testing is 81479 (provided as guidance only).


Specimen Collection

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: 7 business days, faster turnaround available for clinical trials