PGx testing is the new standard for testing patient drug sensitivity
DNA testing CYP450 pathways address over 80% of prescribed medications?
The interpretation of the results of molecular genetic tests can be considerably more complex than is involved in interpreting the results of more traditional laboratory tests such as electrolytes, hepatic and renal function panels, CBC and hormone levels.
What to know – The effects of most medications are dependent on any specific medication being metabolized in the body. That metabolism is a result of the action of enzymes. These enzymes are proteins that are coded in the individual’s DNA. Most medications are metabolized in multiple steps performed by various enzymes coded by multiple genes located along different segments of the DNA, often on multiple chromosomes. The largest group of enzymes responsible for the metabolism of all drugs is found in the Cytochrome P450 pathways.
The Cytochrome P450 pathways consist of more than 50 enzymes of which six are principle enzymes in the metabolism of more than 80% of all drugs. These are coded for the super-genes in the CYP2D6, CYP3A4, CYP1A2, CYP2C9, CYP2C19, and CYP3A5, the first two being the two most significant of these.
Genes can influence how a patient will respond to any given drug or class of drugs. The gene for anyone enzyme may contain one or more polymorphisms or SNiPs, each of which may increase the rate of the enzymatic reaction, decrease the rate of reaction or not affect the enzyme reaction. These effects correspond respectively to what are termed hyper-metabolizers, poor metabolizers, and wild-type (“normal”) metabolizers.
Combined with this is the fact that some drugs are active as they are administered, such as Propranolol and Ibuprofen. Other drugs, such as Codeine and Hydrocodone, are inactive as taken and must be metabolized by an enzyme in the Liver (CYP2D6 in the case of codeine) to an active metabolite to have the intended physiologic effect. For this reason, these drugs are referred to as ProDrug.
Medication DNA testing doesn’t have to be cryptic and confusing and with a simple 2-3 page PharmD report you’ll be furnish with easy to read reports. Our PharmD reports will give you an assessment of any risk factors as well as a review of your patient’s genomic testing and how the metabolism of many drugs and drug classes will be affected. You will receive a list of medications with which you should expect normal or wild-type metabolism, with this list of medications you are empowered with the knowledge to make the right choices for your patient. Then, you can consider altering the normal dosing and a list of any drugs for which you should consider using an alternative agent because of concerns for either safety or toxicity.
Knowledge and medication DNA testing will provide dosing guidance based on this type of testing for over 150 frequently prescribed drugs. With breakthroughs in this exciting area of scientific technology, additional medications will be are added. The FDA has gone so far as to include “Black Box Warning*” on medications such as Warfarin, Avandia, Zoloft, and Plavix.
First, a Med Tech will perform the test, with a buccal swab collecting saliva and dead skin cells are collected, so NO blood-work is required.
Second, the sample is then shipped to us in a sterile bio-bag. We ask that you include patient demographics and a medication list neatly packaged in a pre-paid FedEx envelope. The lab will analyze the test for your patient.
Third, when the test is ready (7-10 days) the physician can access patient-specific data online through the HIPAA compliant web portal and print out if needed.
Pharmgkb.org curates comprehensive databases of genes and medications to better educate clinicians and researchers about the impact of genetic variation and drug response. They gather information from a wide variety of resources, including U.S. and international clinical research groups, government bodies including the FDA, and independent resources such as Drugbank and academic groups.
One of the best attributes of PharmGKB is their accessibility and comprehensiveness. They offer interactive SNP features and tools for education and clinical implementation of genetic data.
We encourage you to visit their site and learn more about pharmacogenomics and its applications. Please go to PharmGKB to learn more.
Knowledge of an individual’s CYP450 make up can shed light to how this individual metabolizes different medications and can aid a physician to make informed choices on the start of therapy with certain drugs, adjust dosage and/or eliminate or replace certain medications that the patient is currently on.