FAQs

If you don’t find the answer to your question below, please contact us at 800-DNA-TEST (800-837-8362).

Q: What are adverse drug events?

An adverse drug event (ADE) is an injury or illness caused by a drug or by the way a drug is used. The type of ADE depends on the drug or combination of drugs being taken. Many ADEs occur because of individual differences in how the body processes a drug or drug combination. Three-fourths of all ADEs are related to the amount of a drug a person takes (too much or too little). ADEs result in more than 100,000 deaths each year, making them the fourth leading cause of death in the U.S. Our partners with the YouScript® Precision Prescribing System prevents ADEs by identifying relevant drug-drug and drug-gene interactions.

Q: What is pharmacogenetics?

Pharmacogenetics is the study of how individual people respond to drugs based on their genetic makeup. When you take a drug, enzymes in your liver, intestines, and other tissues break down that drug so it can be excreted. Your genes provide the instructions to make these enzymes, several of which may be involved in the breakdown and excretion of any particular drug.

The P-450 family of drug metabolizing enzymes inactivates most prescription drugs. The most important and thoroughly studied of these enzymes are CYP2D6 and CYP2C9. It is estimated that more than half of the population has at least one defect in these enzymes – which can greatly increase the risk of an adverse drug reaction. Your specific genetic makeup determines how these enzymes interact and whether they work faster or slower than average.

Q: What genes are most useful to test?

  • CYP2D6 is the best-studied drug-metabolizing enzyme and affects 25% of all prescription drugs. 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 influences the metabolism of Coumadin® (warfarin), Amaryl® (glimepiride), isoniazid, sulfa, and ibuprofen. Clinical studies suggest that the use of genetic testing may be especially helpful determining correct warfarin dosing. Other drugs thought to be metabolized by CYP2C9 include, amitriptyline, Dilantin®, Hyzaar®, THC (tetrahydrocannabinol), naproxen, and Viagra®.
  • CYP2C19 is associated with the metabolism of carisoprodol, diazepam, Dilantin®, and Prevacid®

Q: How has DNA drug sensitivity testing been used up to this point?

Drug companies regularly use these tests in clinical trials, to exclude people for whom the drug will be dangerous or ineffective. Medical centers around the country are also beginning to use these tests on their own patients, to avoid serious drug side effects and achieve more accurate prescribing.

Q: Why is DNA drug sensitivity testing just now becoming available?

There are many reasons:

  • Key parts of this test have only recently been developed.
  • Many doctors do not realize the extent of the problem of serious drug side effects, which leads to more than 100,000 deaths in America each year.
  • Drug companies and insurance providers have been concerned about the costs associated with testing.

Genelex has made its tests available to the public so people can benefit now from recent pharmacogenetic advances. We also recognize that more people want to take greater responsibility for their own healthcare, and support that decision.

Q: Do I need a prescription to order this testing?

Yes, you need a prescription from your doctor. You or your doctor can download the DNA testing request form.

Q: Will DNA drug sensitivity testing be covered by my medical insurance?

Insurance is now consistently reimbursing for DNA drug sensitivity testing, under specific circumstances. These include:

  • Patients who have adverse drug reactions or do not respond to a prescription drug
  • To determine the best medication for managing pain
  • To determine if a patient will be helped by a specific type of cancer treatment
  • To select a safe and effective drug regimen for patients with many different medical conditions

Genelex has submitted multiple claims with several insurance providers, almost all of which have been paid at an acceptable rate. Genelex will work with you to reduce out-of-pocket expenses. Depending on your insurance plan, you may still be responsible for a deductible or co-payment.

Please note that testing is usually covered only for specific medications and conditions, not when it is used for general screening. If this is a concern, contact your insurance provider about coverage prior to ordering DNA sensitivity testing.

Even if DNA sensitivity testing is not covered by your insurance, many patients think that a one-time expense is well worth it when the benefits of testing are considered. Since your DNA never changes, the test results are good for life.