Podcast: New Codeine Guideline and More Help With Pharmacogenomics

Suddenly, genetic testing is entering the realm of primary care. About 10% of FDA approved drugs now mention genetic tests on their labels, relating to genes known to control how the drug is metabolized. Once the province of medical geneticists, pharmacogenomics is beoming a must-know topic for family doctors as well.

Here to help  is a new gene testing registry launched by the NIH and, behind much of the information there, the actions of the independent Clinical Pharmacogenetics Implementation Consortium (CPIC), which issues guidelines about the use of gene tests to improve drug response. Here to discuss CPIC, its guidelines, and the latest release on codeine(Drug information on codeine) and the gene called CYP2D6.

Dr Relling is chair of the pharmaceutical department at St. Jude Childrens Research Hospital in Memphis, and a founder of CPIC.

FEATURED QUOTES:

"We have to avoid codeine and tramadol(Drug information on tramadol) in ultarapid metabolizers and those 10% of the population that is poor metabolizers don't get any benefit at all."

"Much of this information has actually been known for 20 or 30 years. One of the reasons that we have been held back is that testing hasn't been as widely or inexpensively available as it is now."

The questions:

1. What is CPIC?
2. Who is behind CPIC? Who are the members?
3. Which guidelines have been issued so far?
4. Why was the new codeine guideline necessary and what does it provide?
5. How widely available are the genetic tests that underlie pharmacogenomics?
6. How likely is it that a patient's insurance will pay for these tests?
7. What are the odds that a primary care doctor will need to know about this in the near future?

Resources:

The Pharmacogenomics Knowledge Base
A project involving CPIC and the Pharmacogenomics Research Network

The NIH Gene Testing Registry

CPIC guidelines:

HLA-B Genotype and Abacavir(Drug information on abacavir) Dosing
Clinical Pharmacology and Therapeutics, April 2012

Codeine Therapy in the Context of Cytochrome P450 2D6 (CYP2D6) Genotype
Clinical Pharmacology and Therapeutics, February 2012

CYP2C9 and VKORC1 genotypes and warfarin dosing
Clinical Pharmacology and Therapeutics, October 2011

Cytochrome P450-2C19 (CYP2C19) Genotype and Clopidogrel(Drug information on clopidogrel) Therapy
Clinical Pharmacology and Therapeutics, August 2011

Thiopurine Methyltransferase Genotype and Thiopurine Dosing
Clinical Pharmacology and Therapeutics, December 2010