Cytochrome P450 Genetic Testing
Posted 27 November 2009 - 02:08 PM
Posted 27 November 2009 - 05:20 PM
This is the first I have even heard of this testing. I'll do some checking into it. One word of caution, be very careful of the information you find on the web. Make sure you are taking information from "reliable" sites....not just forums where people often go to vent.
Hopefully someone will come along shortly who would be willing to share some personal experience.
Posted 28 November 2009 - 12:20 AM
Hi, has anyone known or or heard from other people if the genetic Cytochrome P450 test helped them get a treatment for their depression? I have a friend who said her sister got the test and they were able to find the right kind of medication and dose to help her get a better depression treatment plan. However, some sources online are saying the test is useless and not to do it. Has anyone here had experience with or know about Cytochrome P450 testing?
I agree with the people that say the test is useless -almost- in that it cannot be used to predict a drug's efficacy.
Cytochrome p450 is a group of many liver enzymes - like cyp 2d6 - that break down foreign chemicals - like prescription anti-depressant drugs for example.
Each person has a group of genes related to production of these enzymes. These genes can have variation in them that can affect how much of them you make. You can test for these varations.
Variations generally include what amounts to a ultrafast, fast ,intermediate , slow metabolizer of certain types of drugs (associated with whatever enzyme gene is being tested).
If you are a slow metabolizer of say, cyp2d6, drugs like paxil , prozac, and flexeril are broken down slower and remain in your system longer. This would significantly increase their effect on you. If you knew this by taking a test, the doctor would precribe a lower dosage than what's considered 'normal'.
The test only shows what gene variant you have associated with production of these enzymes in liver. This test -does not- give you information on efficacy of a drug - especially one that interacts with neurotransmitters. It would only help choose dosage and avoid possible side effects associated with higher-dosage. Depending on if you were a fast/slow metabolizer of a certain drug, you'd have less/more drug 'plugging' up your post synaptic receptors - but that's not a guarantee of anything really.
If you were an ultra-fast metabolizer associated with a particular enzyme, you'd clear the drug out so fast it would have very little effect at all. This what I see as the most useful tool - as you can increase dosage to achieve -possible- efficacy.
The test also would help predict possible problems with drug interactions if you are on several that use the same enzyme. If you were a slow metabolizer associated with cyp 3a - and took both prozac and xanax - the effects of one would be increased compared with if you took one alone.
Basically, I think it's making it seem too simple to say the efficacy is -only- or even largely related to the rate of breakdown of the drug. When you say your sister found the -right- kind of drug because of this, i'm not convinced that if she took the -wrong- kind at a different dosage - that it wouldn't work; Or if she took the -right- kind at any dosage it would work. So...the test can help out a little bit, probably only with dosing issues of certain drugs. The odds are very low , from what i've read, that someone would be an ultra-extensive 2d6 type metabolizer ~1% or slow ~5%.
This is just my opinion. I haven't made a complete judgement on it myself - although I'm presently leaning on too expensive for what little results it probably would actually yield.
Edited by ribosome77, 28 November 2009 - 12:23 AM.
Posted 28 November 2009 - 12:54 AM
I have heard of this test before, but it did not appear to widely used by any Doctor I have known.
The cytochrome P450 blood test provides information on how a person's body metabolizes (breaks down) drugs. Genes are contained in each of the body's cells. They instruct the body to produce proteins that control how cells grow and function. This test identifies the gene or genes responsible for producing enzymes to metabolize these drugs.
This is a genotyping test and a very simple one at this stage. I would suspect that in the future Doctors/Scientists will be able to identify the actual genes related to mood change and a more effective way to deal with depression will be developed. I do not think that there are any claims anywhere that this test will do anything else but give simple feedback . It does not yet appear to be a useful tool.
I personally do not think it is worth spending any money on these kind of tests because they give so little information.
Information supplied on Depression Forums by members should not be relied upon and is not a substitute for medical advice from a health professional or doctor.
Posted 05 December 2009 - 01:36 PM
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