View Full Version : Genetic Testing for Focalin

03-17-17, 01:06 PM
I tried Focalin but it caused palpitations & psychosis (seeing things). I found a great resource on Focalin side effects with Rxight Pharmacogenetics. I got tested with them also, and their genetic test showed I am "red flagged" for Focalin and other stimulants due to my genetics Specifically I am a "rapid metabolizer" and therefore prone to toxicity at standard doses. So my doctor put me on a lower dose of Focalin and I am doing fine now. I highly recommend genetic testing if you're not sure if your medication is working or if you're experiencing side effects.

03-17-17, 01:18 PM
I'm surprised that your doctor was willing to keep you on Focalin after it induced psychosis, but I'm glad you've found something that works for you without the serious side effects.

This is the reason knowledgeable doctors start with low doses of stimulants and titrate upwards slowly -- to see if low doses produce therapeutic effects without the side effects. In general, serious side effects are enough to tell a person that their dose is too high or that the medication isn't right for them, without the need for additional genetic testing.

For information, it looks like this particular test panel looks for mutations in the genes for:

adrenoceptor alpha 2A (ADRA2A),
ANKK1/DRD2 related to the dopamine D2 receptor,
catechol-O-Methyltransferase (COMT),
cytochrome P450 2B6 (CYP2B6),
cytochrome P450 enzyme 2C8 (CYP2C8),
cytochrome P450 2C9 (CYP2C9),
cytochrome P450 2C19 (CYP2C19),
cytochrome P450 2D6 (CYP2D6),
cytochrome P450 3A4 and 3A5 (CYP3A4 and CYP3A5),
dihydropyrimidine dehydrogenase (DPYD),
kainic acid-type glutamate receptor (GRIK4),
an endogenous serotonin receptor (HTR2C),
methylenetetrahydrofolate reductase (MTHFR),
mu- opioid receptor (OPRM1),
a liver-specific transporter (SLCO1B1),
thiopurine S-methyltransferase (TPMT),
uridine diphosphate glucuronosyl transferases (UGT2B15*), and
and the anticoagulant vitamin K epoxide reductase complex, subunit 1 (VKORC1).

Some of these are liver metabolism-related, some of them are receptor-related, some of them have to do with other body systems (e.g. blood coagulation). This particular panel is not specific to ADHD meds or psychotropic medications, so it tests for some mutations that may not necessarily have a lot to do with response to ADHD meds (but might be important for people taking statins or blood thinners or other types of meds).

My own experience with genetic testing (using a different commercial test with a smaller panel of genes, more focused on those related to ADHD medications) after failure of several medications was that it didn't reveal anything unusual, metabolism-wise. I heard an anecdote from a clinician at an ADHD clinic (so take it for what it's worth) that there was one person who tested positive for a mutation that would supposedly reduce the effectiveness of a certain medication -- and it turned out that that was the only medication that really worked for him!

This is just to say that the genetic tests on the market today are limited in what they test for. Occasionally they do reveal an important mutation in a metabolism- or response-related pathway, as they seem to have done in your case -- but there are many interactions we don't yet understand.

If you're experiencing side effects, you don't necessarily need a genetic test to tell you that the dose is too high. But if you consistently have problems with side effects from multiple medications, even at low doses, or you have trouble finding a medication that works, despite being pretty sure about the diagnosis after a thorough evaluation, then these tests can occasionally help you and your doctor understand if there are particular metabolic quirks that might be affecting you.

Anyway, again, glad to hear you were successful in troubleshooting you side effects and in finding something that works.

04-02-17, 08:39 PM
Who ordered your genetic testing? I would really like to have this done the right way the first time around.