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Which Drug Can Give A False Positive For Methamphetamine?

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Posted on Mon, 18 Sep 2017
Question: I tested positive for meth on a 10 panel drug screen, even though i never have smoked meth. my question is this: is it possible to inhale meth unwittingly riding in a in a handicapped taxi van sitting up high in the van for about 25 minutesand as a result test positive for meth about 30 minutes later.
doctor
Answered by Dr. Dr. Matt Wachsman (27 minutes later)
Brief Answer:
not...really....

Detailed Answer:
but methamphetamine is a small, simple substance that is quite similar to the compound that is used to manufacture it ...pseudophedrine. which is found in decongestants.
This is one among many other drugs that can give a false positive.
Amantadine (Symmetrel), bupropion (Wellbutrin), chlorpromazine, desipramine (Norpramin), fluoxetine (Prozac), L-methamphetamine (in nasal decongestants*), labetalol (Normodyne), methylphenidate (Ritalin), phentermine, phenylephrine, phenylpropanolamine, promethazine (Phenergan), pseudoephedrine, ranitidine (Zantac), thioridazine, trazodone (Desyrel)
http://www.aafp.org/afp/2010/0301/p635.html
Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar
doctor
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Follow up: Dr. Dr. Matt Wachsman (24 minutes later)
i didn't take any of the drugs you listed. however i was on adderall 30 mg day at the time. you really didn't answer my question, i asked if it was possible.....for instance if a driver just smoked some meth 5 minutes before he picked me up; wouldn't it be in the air and i would be breathing it fior 25 minutes, could that be enough in your system to cause a positive. please don't answer not really. do you know for a fact that my suspicion COULD be correct.

fyi, i take trazodone most nights, but wasn't at the time of the test.
doctor
Answered by Dr. Dr. Matt Wachsman (1 hour later)
Brief Answer:
NOt really, as previously stated.

Detailed Answer:
No
It is not possible.

BUT amphetamine would show up as amphetamine.

Adderall is amphetamine. "Generic Name: amphetamine and dextroamphetamine"
https://www.drugs.com/adderall.html

It would show up on the test as amphetamine.


Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar
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Follow up: Dr. Dr. Matt Wachsman (26 minutes later)
i'm confused. are you saying my adderall is the cause of my false positive for meth? how could that be? the previous doctor said pseuephedrine is the active ingredient in meth? but it is not contained in adderall, is it? i am not saying that i tested positive for amphetamines, which was supposed to be in my system, i tested positive for meth. it would have been acceptable for me to test positive for amphetamines because i was on adderall, but it still doesn't make any sense to me if i did not have any pseudoephedrine in my system except for inhaling it in the handicapped van,,,,
fyi, i live in the meth capitasl of our state.


if the driver(s) of the van regularly smoke meth in the van, and you inhasled it, wouldn.t it go in your bloodstream and show up during the appointment as nervousness and test positive in a urine test 30 minutes later? i believe i was unknowingly high on meth at my last 2 appointments with my psyhiatrist. he took away me adderall because of my nervousness at the last 2 appointments because i believe meth was in my system due to the handicap van being infultrated with meth. am i crazy?
doctor
Answered by Dr. Dr. Matt Wachsman (28 minutes later)
Brief Answer:
I have answered the questions.

Detailed Answer:
The site clearly indicates I am the doctor who has answered all of the questions.

First let me say again, It is not possible to get enough drug into the air that inhaling it would give a false positive. That would have to be enough powdered drug to be visible like a snow storm. It would not stay in the air in sufficient quantity. The test is NOT sensitive to SMALL amounts.

No.

Then, based on the previous drug blank (which is confusingly called "previous drugs tried" and not "list of medicines currently taken"), the first answer was given assuming that the question was from someone who is NOT taking any prescribed medicines. In this case, other drugs that cross react (pseudophed) that do not require a prescription were mentioned.

Then in answering the follow up when knowing someone IS taking AMPHETAMINE. That is the cause of a positive drug test for methamphetamine. They are indeed as similar as they sound and only very specialized tests have any hope of distinguishing between them; even then, this may fail if the level of amphetamine is high (due to regularly taking adderall as prescribed) and the test is set to detect very low levels of methamphetamine. The better tests show SLIGHT differences between them but the differences are not enough to distinguish between DAILY taking ADDERALL and taking methamphetamine ONE TIME 3 days prior. Pseudophed can also show up for the identical reason. If someone were taking both Pseudophed and adderall either could show up as methamphetamine. Actually, looking at the laboratory manuals, pseudophed more commonly cross reacts than adderall simply because the usual dose of SUDOPHED is up to 200 mg in a day. and the usual daily dose of adderall is 40 mg. Look at a pseudophed capsule. Can that much dust be in the air and inhaled ?


It Was The Adderall. Or perhaps pseudophed, but only if someone was taking pseudophed. It was not inhalation.
Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar
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Follow up: Dr. Dr. Matt Wachsman (45 minutes later)
i was not taking pseudoephred. then, are you saying i tested positive for meth
simply by taking 30 mg of adderall a day? my doctor called me a great atress or said i stopped taking meth and passed the test today. why then did he take me off adderall 5 monthds ago? i have been with this psychiatrist for 17 years, and it breaks my heart now that i believe he doesn't trust me anymore. he, too, is an addiction specialist and should i even mention my theory?
doctor
Answered by Dr. Dr. Matt Wachsman (10 minutes later)
Brief Answer:
I'm sorry if I mis interpret what you are saying.

Detailed Answer:
I think you are saying that this false positive test occurred 5 months ago, the doctor accused you of lying (personally, I do not think that of you), and then took you off of adderall. This would imply that whatever you were taking the amphetamine for, is not currently being treated. Well, at some age, it isn't that good of an idea to keep giving someone a strong stimulant like adderall.

Sorry this happened to you when false positives are quite common. If it wasn't confirmed by the better and more expensive test (GAS CHROMATOGRAPHY with MASS SPECTROSCOPY), then it just isn't a real result and the usual dipstick and less expensive tests just do not distinguish between adderall and methamphetamine. Someone might think they had a better test than what they do.

I don't think the inhalation theory is going to convince many people. It's really whether the amount of drug can get into the spot where the test is. Getting a small amount of drug powder into hair before a hair test is a thing because ALL of the powder goes into the test. With inhalation, whatever is inhaled has to get through the whole body and then it is diluted by days worth or urine. It would be so diluted it could never be detectable.
Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar
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Follow up: Dr. Dr. Matt Wachsman (5 minutes later)
this test was sent to california for analysis. we live in the midwest. could one of the more highly evolved tests have determined inhalation of meth?
doctor
Answered by Dr. Dr. Matt Wachsman (20 minutes later)
Brief Answer:
Ok, the inhalation did not happen.

Detailed Answer:
But, yes, if there was methamphetamine flying as a dust cloud in the air, then it would get over everything. The dust cloud would not fly like an angry horror movie possession specifically up into your nose. The methamphetamine dust cloud would randomly move outward and disperse. If enough to show up later in your urine got into you (more than 10 mg) then it would literally be covering your clothes. The methamphetamine dust cloud would be diluted after it got into you and even more after it goes into the urine but the dust settling onto your clothes would just stick there.

So, if you were in an amphetamine dust cloud, the clothes would test more positively than the urine. There are actual test kits
https://www.homehealthtesting.com/substance-test-c-21_53.html

DRUG SUBSTANCE TESTS are how they are listed. They are cheap. I am not sure about their accuracy. They are not meant to be sensitive nor that specific because for the reasons listed above they are supposed to be used to detect fairly large amounts of drug.
Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar
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Follow up: Dr. Dr. Matt Wachsman (8 hours later)
what if all the windows are closed and you breath through your mouth as well as your nose as i do? you said the cloud would disperse - how long does the dispersion take if a good or large amount of meth was just smoked 5 minutes earlier?
doctor
Answered by Dr. Dr. Matt Wachsman (6 hours later)
Brief Answer:
Why do you want to believe in something so very wrong.

Detailed Answer:
Nobody reports a second hand high with methamphetamine.
There is zero reports of any of this in the literature.
I gave you a way to confirm or rule it out and you aren't interested in that.
Let us assume that someone were around it enough to literally gag on it.
Let us assume they are in it for at least 8 hrs a day
Let us assume that they have a metabolic failure so that it stays in the system 3 times longer than ever recorded in humans.
Then it would be like tobacco second hand smoke

and.....its level at most would be about 1% of those who are actively taking it.
So, the dispersion is like any scent. fast in a small closed space. How long it stays in the air depends and it would be small with methamphetamine (the smell does not linger as much as cigarette smoke for example). You would get no more and maybe less into you if you breathe through the mouth. Obviously people who breathe through the mouth do not get more air in; you don't blow up like a blimp and explode. But, the mouth doesn't absorb drug as well.

So, it's never been seen. Addicts do not notice it. It is far less of an effect than with cigarettes and the level obtained with cigarettes is too small to be a factor and this would be far far less than with cigarettes. Likewise with marijuana which is stickier, stays in the system Far Far longer than cigarettes; while there is a very small secondary effect, the amount in the blood and urine after second hand smoking is about the 1% (or less) than with cigarettes.

Every bit of research, observation, math, and common sense says second hand exposure is irrelevant. I am anxious to see what you do to keep arguing for it.
Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar
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Dr. Dr. Matt Wachsman

Addiction Medicine Specialist

Practicing since :1985

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Which Drug Can Give A False Positive For Methamphetamine?

Brief Answer: not...really.... Detailed Answer: but methamphetamine is a small, simple substance that is quite similar to the compound that is used to manufacture it ...pseudophedrine. which is found in decongestants. This is one among many other drugs that can give a false positive. Amantadine (Symmetrel), bupropion (Wellbutrin), chlorpromazine, desipramine (Norpramin), fluoxetine (Prozac), L-methamphetamine (in nasal decongestants*), labetalol (Normodyne), methylphenidate (Ritalin), phentermine, phenylephrine, phenylpropanolamine, promethazine (Phenergan), pseudoephedrine, ranitidine (Zantac), thioridazine, trazodone (Desyrel) http://www.aafp.org/afp/2010/0301/p635.html