Fast drug metabolizers?

Discussion in 'General Parenting' started by gcvmom, Jan 11, 2009.

  1. gcvmom

    gcvmom Here we go again!

    I'm curious if anyone else or their difficult child has been told they metabolize medications quickly?

    I've read that this can be the case with children because their liver clears the drug faster with some medications and they need a higher dose than what would typically be given by their weight.

    I'd like to know why this happens, so if anybody knows, please share. (I know, I could ask a pharmacist, or I could have asked the psychiatrist if I'd thought about it on Friday, but this place is more fun).

    What I wonder also is if this is something that evens out as they grow older, that is to say, will they always need higher-than-usual dosing or will it eventually level out to a more normal level?
  2. smallworld

    smallworld Moderator

    There are actually genetic tests that can be performed on the liver enzymes and how they metabolize certain medications. It's expensive, but might be worth it to understand what's going on with your difficult child and Seroquel.
  3. gcvmom

    gcvmom Here we go again!

    SW, I wasn't aware of that!

    The psychiatrist is fine with the dosage he's on now, and he said if it truly were too much for him, his affect would be flat, he would be so sedate that he wouldn't be functioning, and yet he clearly is. It's the psychiatrist who said he's amazed at how fast difficult child 2 is burning through this stuff, especially when I tell him what he's like if a dose is missed or is late. He said most people would have enough in their system to keep them stable despite any dosing variations. And the fact that he's so sensitive to any variation in the amount of stimulant he gets is also telling.

    I guess as the mom, I just am curious if he's always going to be like this, or if it's strictly because of his age. I guess a blood test would tell us if his liver is being stressed too much, too.

    The psychiatrist offered to run a fasting glucose since I am a bit concerned about his weight -- although he was practically anorexic a year ago before we got him off the higher dose of stimulants, he's now crossed the line and has a belly forming, which isn't healthy either.

    Then again, maybe I'm just obsessing again and should be thankful he's as stable as he his. Things could be much, much worse!

    I'll ask about the genetic test anyway. Can't hurt.
  4. flutterbee

    flutterbee Guest

    I metabolize any of the caine's very quickly (lidocaine, novacaine, carbacaine, etc). I don't know if that goes through the liver or the kidney's.

    I don't know about any other medications or testing. I just know that it makes fillings a lot of fun. :faint:
  5. gcvmom

    gcvmom Here we go again!

    Okay, found it.

    UC Irvine Pathology Services offers the CYP450 Amplichip test to determine whether you have the genotype designating what type of drug metabolizer you are!

    Here's an excerpt from their site:
    • The majority of people are extensive metabolizers who can be administered drugs following "standard" dosing practices
    • Some people are intermediate metabolizers, meaning that they metabolize drugs at a slower-than-normal rate—somewhere between the rates of poor and extensive metabolizers. Multiple drug therapy regimens can turn these people into poor metabolizers because drugs can also inhibit their metabolic enzyme activity
    • Some people are poor metabolizers with a "deficiency" in drug metabolism, which could lead to life-threatening drug accumulation and severe adverse reactions
    • Some people are ultrarapid metabolizers who break down drugs at faster rates than extensive metabolizers. These people may experience either no effect or less-than-expected effectiveness from their drug therapy
    The only downside is cost, of course. Most insurance plans still consider this investigational, and the cost is anywhere from $600 to $1,300.

    I'll call the lab tomorrow just for yucks and see what they charge.
  6. totoro

    totoro Mom? What's a GFG?

    That would be interesting to know! Especially for those of us on things like MS or AP's or pain medications... and our kids!
    Too bad it is costly. Of course.
  7. susiestar

    susiestar Roll With It

    I have always thought I handled medications differently than other people. I think htis would be fascinating info! I may call the local lab to see if any in my state do this test. What AWESOME info!!
  8. gcvmom

    gcvmom Here we go again!

    I forgot to mention that UCI is not the only lab that offers this test. There are several around the country. If you google Amplichip, you can read more about the test and where it's offered.

    I imagine there must be other companies that have developed a similar test -- but then again, they may be one of the first.

    There is big money in genotype testing for drug metabolites. difficult child 1 underwent something similar for the immunesuppressant he takes to control his Crohn's. And while it shows if the medication is within therapeutic levels for him, we found out the hard way that our insurance does not cover this $250 test. :(

    The argument for this testing is that it can save someone who is more likely to develop a toxic reaction because they are poor metabolizer. But then, the counter argument is that this is the reason doctors typically choose the slow route for titrating medication dosages -- it allows them to carefully monitor how the patient responds to the drug without pushing them into dangerous levels. The only problem for the patient is that you have to be PATIENT and wait to see how the drug will work for you. In the case of a child whose life is being affected by their disease (mental or physical) time is critical because they only have so much time for their physical growth, their psycho-social growth, and their education.

    Until the insurance industry buys off on the value of this type of designer testing, the rest of us will probably have to live with doing things the old fashioned way :D
  9. Ropefree

    Ropefree Banned

    My son is adhd and he eventually took the time released version of concerta in the long road to trying to give him something that was not so up and down like the doses through the day were for him.
    The time released version was suppose to last 11 hours. he had it done in 7.
    the option to give another dose of the short version we rejected.
    I feel that being comfortable with ones own natural state is important. Especially for
    One day the science will be up to speed. Until the information sharing between the
    folks who are studying the mental health and treatments for children has been done
    we are all test subjects as the physician 'practises' medicine. The relationship between the patient and the practioners that treat is one that is of mutual beneifit.
    When successful treatments are aplied the patient is benefiting. When the treatment is not successful the practioner is (hopefully) learning something.

    The sciences and education are 'proformance arts' and we who are engaged in this are giving oppertuities to gain the knowledge and skillful care for the benefits of the greater good.

    The test for the type of metabolic function one shows seems like another diagnostic tool that needs to be applied far more readily and therfor the cost needs to decrease inorder for the evidenced testing to give a fact based picture of what is 'normal' variation and to adjust with that flexability sensitive to the specific needs of the patient in treatment.

    I am not a betting type. I only wager when I see guarenteed win on the horizon.
    I bet that if I took that test my metabolism would be right about the speed of a slug!
  10. gcvmom

    gcvmom Here we go again!

    I agree that the tests should be made more affordable and that insurance companies should cover them! For now, though, it's the old fashioned trial and error method via slow titration I suppose.