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Can Cocaine be detected in hair drug test?

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Posted on Wed, 2 Dec 2015
Question: My son tested positive for cocaine but negative for all of the metabolites for cocaine, including benoylecgonine. Is this possible? Thank you.
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Answered by Dr. Matt Wachsman (42 minutes later)
Brief Answer:
a few different ways!

Detailed Answer:
first, I am assuming it is GC Mass spec? because if it is NOT, then the most common (and it IS COMMON) way is that the test messed up and is detecting one of many cross reacting drugs such as some tricyclic antidepressants. If it doesn't have an exact amount with a limit of detection attached to it, then I would be a bit dubious about the test.

Then, further evaluation would depend on the levels of the drugs and detection limits. If the drugs are all near their limit of detection then it could be a false reading or the metabolite got out of the system faster, or someone just took a small amount right before the test and the metabolite didn't form enough to register.

(but my bet is they won't have the levels because it wasn't the good test, but a dipstick taht is reading the wrong drug).
Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar
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Follow up: Dr. Matt Wachsman (7 minutes later)
It was a hair test. The levels are Cocaine LCMSMS 1151 pg/mg, and benzoylecgonine LCMSMS negative (screen cutoff at 50 pg/mg). It seems impossible that the coc level would be so high (100 times the screen cutoff) and the benzolecgonine would be completely negative. Could this be from environmental exposure?

My son admitted to taking 2 hits off a joint that made his mouth go numb. This was at a concert 3 days before the hair sample was collected. We insisted on the hair because he did a urine test the day after the concert, and it was positive for cocaine. I thought the hair test would only pick up drugs that he'd used 7 days before sample collection or before; so I though it would show THC only and satisfy my husband. Instead, it seems unreliable.

Further thoughts? Thank you.
doctor
Answered by Dr. Matt Wachsman (36 minutes later)
Brief Answer:
yes, that is well known in the literature.

Detailed Answer:
was going to say, getting some actual cocaine ON the hair.
http://www.yyyyyyyyi.nlm.nih.gov/yyyyy/0000
takes under a minute to find examples in the medical literature of this.
Indeed, there are specific guidelines that if there are NOT metabolites it is NOT drug use.
http://www.yyyy.nlm.nih.gov/yyyyyyyyy/0000

Apparently hair products that make the hair stickier increase the possibility of this.
http://www.yyyyyyy.yyyyy.nih.gov/yyyyyyyy/0000

There is still the urine test and that depends on whether the GC MS test was used. If the GC-MS test was used on the urine it would show both cocaine and metabolites if they are present.

Still, most people do not have cocaine in their hair from their environment. It still isn't exactly a good sign even if it is most consistent with environmental exposure rather than use.

Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar
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Follow up: Dr. Matt Wachsman (13 hours later)
One quick followup: doesn't the level found (1151 pg/ml) seem ridiculously high? Is that a level you would expect for frequent use? or is it incredible even for frequent use? The very high level itself seems to put the result in question. Then add in the negative for benzo, and it seems that the test is completely unreliable. This is a child who has straight A's -- in AP classes like AP Physics C. It doesn't seem possible that he uses cocaine at the level that would show this astronomical amount of coc in/on his hair. Can you provide some perspective here?

I agree it is not a good sign. What I think we will do is require him to urine test on a regular basis starting in a couple weeks when any cocaine should have flushed out of his system. We use over the counter urine tests from the drug store. Is there a certain type that you would recommend?

Thank you for the help.
doctor
Answered by Dr. Matt Wachsman (3 hours later)
Brief Answer:
depends on the context of the test.

Detailed Answer:
a sky high level in the hair without ANY metabolite means it's external contamination and sky high levels are the usual result in that context. This is also found on
http://news.yyyyyyyyyyyyyy.com/news/2009/08/090816-yyyyyyyyyyyy-money.html

The over the counter tests are not very reliable. Period. If they are negative that is a pretty good indicator of not using that week. If they are positive I would really question if that is correct since many common prescriptions (most anti-depressants for a start) will cross react with cocaine.

Oh, this is contingency management:
1) kid's probably ok
2) don't want to make the relationship terrible
3) want to show faith/confidence that the test will be negative
THEREFORE, tie the test to a really GOOD reward, like 10 bucks x number of clean weeks (ok.. maybe like 5). So... 1 week clean is 5. next week clean is 10, up to 50 dollars in week 10. And... at 20 bucks per urine test x 10...it's still cheaper than 3 counseling sessions, 1 week of rehab, or 3 really good urine tests.
Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar
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Dr. Matt Wachsman

Addiction Medicine Specialist

Practicing since :1985

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Can Cocaine be detected in hair drug test?

Brief Answer: a few different ways! Detailed Answer: first, I am assuming it is GC Mass spec? because if it is NOT, then the most common (and it IS COMMON) way is that the test messed up and is detecting one of many cross reacting drugs such as some tricyclic antidepressants. If it doesn't have an exact amount with a limit of detection attached to it, then I would be a bit dubious about the test. Then, further evaluation would depend on the levels of the drugs and detection limits. If the drugs are all near their limit of detection then it could be a false reading or the metabolite got out of the system faster, or someone just took a small amount right before the test and the metabolite didn't form enough to register. (but my bet is they won't have the levels because it wasn't the good test, but a dipstick taht is reading the wrong drug).