For those who have asked....DNA enzyme testing for drug metabolism

Discussion in 'The Watercooler' started by buddy, Nov 14, 2011.

  1. buddy

    buddy New Member

    As someone who is not in the medical or pharmacy field, I am trying to look for more information as we are encountering more difficulties with Q's medication responses. So I found a site and took an online webinar and of course had to scare myself to death. They talked about a boy who took Prozac who had the same poor metabolism (PM) rating for CYP 2D6 which means that it built up to a toxic level in a few days and he died. Now, I understand why we had to switch to doing 1ml in a dropper at a time when dosing him even though he weighed around 70 lbs at the time. And why we have not been able to increase it at all. There are some medications that they said add to this problem (can further inhibit enzyme action) so you have to be careful for that (there is a genetic/DNA form and a drug induced form, Q has the genetic form). He has two systems tested as poor/reduced so that means he can have medications be toxic at a very low rate. They showed one medication....maybe it was strattera?? that could be at 25 times the dose in serum blood levels for PM's.

    DNA Drug Sensitivity Testing - Personalized Medicine

    If any of you are pharmacists or doctors or chemists who want to explain this to me in lay person terms, please feel free. I am sure I am butchering this.

    Bottom line, I am so glad I found this site, I printed out the drug lists which are more extensive than what I received and I was told that for Q's profile he will have some medications that can become toxic or have more adverse reactions and for others he will be able to have a lot of the medication. and it may not build up. I thought it may complicate things, did not realize it could actually kill someone.

    Codine is another biggie (and other anesthetic medications) ... it converts to morphine and can be built up to lethal levels and people die. For others it just wont work at all. (rapid metabolizers) . The webinar also talked about how the half life can be so altered that the medication stays in a person for an immensely longer time.

    There are many drugs listed and many are super common and even over the counter.

    Q's insurance (straight MA) covered the testing. I guess I read here many insurances dont cover it, seems like a really worthwhile investment for those who have had many strange drug responses in the past. Could save their life.

    Here is what I copied from the site for those who have asked:

    What genes are most useful to test?
    • CYP2D6 (cytochrome P450 2D6) is the best studied of the DMEs (drug metabolizing enzymes) and acts on one quarter of all prescription drugs. Approximately ten percent of the population have a slow acting form of this enzyme and five percent a super-fast acting form. 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 (cytochrome P450 2C9) is the primary route of metabolism for Coumadin (warfarin), Amaryl, isoniazid, sulfa and ibuprofen. Clinical studies suggest that the use of genetic testing may be especially helpful with warfarin administration. Other drugs that are thought to be metabolized by 2C9 include, amitriptyline, Dilantin, Hyzaar, THC (tetrahydrocannabinol), naproxen and Viagra.
    • CYP2C19 (cytochrome P450 2C19) is associated with the metabolism of carisoprodol, diazepam, Dilantin, and Prevacid.
    • CYP1A2 (cytochrome P450 1A2) is associated with the metabolism of amitriptyline, olanzapine, haloperidol, duloxetine, propranolol, theophylline, caffeine, diazepam, chlordiazepoxide, Premarin, estrogens, tamoxifen, and cyclobenzaprine.
    • NAT2 (N-acetyltransferase 2) is a second step drug metabolizing enzyme that acts on isoniazid, and procainamide and Azulfidine. The frequency of the NAT2 "slow acetylator" in various worldwide populations ranges from 10% to more than 90%.

  2. AnnieO

    AnnieO Shooting from the Hip

    I wonder if my insurance does, because Onyxx sure didn't seem to have much response to anything.

    Then again... That could also have been due to her not taking it/taking too much/illegal drugs.

  3. DammitJanet

    DammitJanet Well-Known Member Staff Member

    Well I know that hydrocodone doesnt build up and end up as morphine and kill me because Im on both and still here!

    I have been on coumadin before and am getting a huge kick about the fact that it is in the same category as pot, viagra , advil and naproxen. LOL. What a confused gene.
  4. buddy

    buddy New Member

    That's just the thing, there are levels and different enzymes, so if you have a poor rating on one and I think it said only on the cyp 2d6 one there are rapid metabolizers...they can't build it up so need higher doses... some people just are super sensitive and that is how they respond. It is confusing to me but at least we know and I can tell pharmacy and the docs always check now.
  5. Liahona

    Liahona Guest

    How did you find this out about Q? I've been thinking of getting difficult child 1 tested because no medications work for him. Did you suspect this because medications didn't work? Or did he have a very unusual reaction?
  6. buddy

    buddy New Member

    Yeah, his pediatrician asked me if he could do it... We had some medications he needed super high doses to be effective and others he would take a tiny amount and it was like he had a bottle of it. So, that is why he decided to check and sure enough, his hunch was right. The web site says usually people get tested after years of strange reactions to medications. Quin had an MRI once when he was little, they gave the highest dose they were willing to try of the anesthesia, and he did not fall asleep. It was so bizarre, I had only been a mom for a few months! Just the beginning, it was.......
  7. TeDo

    TeDo Guest

    psychiatric hospital actually suggested this kind of test for difficult child 1 because of his VERY similar reactions to both Risperdal and Prozac even though they are in different classes. Our psychiatrist actually ordered the test but she doesn't know what it's called or where to go to have it done. Where did Q have his done and what exactly is it called, if I may ask?