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Can Ibuprophen and Naproxen Sodium cause a false positve for THC?

brad2011 posted:

I tested positive for THC this week even though I haven't smoked marijuana in over two years. I did take 1 Aleve and 2 Ibuprofens the night before the test and then 3 ibuprofens that morning because of a sore knee. After testing positive around 11am, I knew it had to be wrong so I bought a home drug test kit and tested clean at around 7pm the same day. I even went to a "doc in a box" type walk-in urgent care facility the next day to have a more accurate urine screen performed and I got the results back today and they were negative, too. So again, my question is, could either the Ibuprofen or the Aleve, or even a combination of both have produced a false positive for THC? Please help me so that I can avoid this in the future...

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4 Replies |Watch This Discussion | Report This| Share this:Can Ibuprophen and Naproxen Sodium cause a false positve for THC?I tested positive for THC this week even though I haven't smoked marijuana in over two years. I did take 1 Aleve and 2 Ibuprofens the night before the test and then 3 ibuprofens that morning because of a sore knee. After testing positive around 11am, I knew it had to be wrong so I bought a home drug test kit and tested clean at around 7pm the same day. I even went to a "doc in a box" type walk-in urgent care facility the next day to have a more accurate urine screen performed and I got the results back today and they were negative, too. So again, my question is, could either the Ibuprofen or the Aleve, or even a combination of both have produced a false positive for THC? Please help me so that I can avoid this in the future...

Betty Ford Center

James Golden, MD responded:

Both Aleve and Ibuprofen can result in a false positive test for THC. With newer testing methods, we can run confirmatory cross-checks to check for interfering substances, such as metabolites in these medications.

Report This| Share this:Can Ibuprophen and Naproxen Sodium cause a false positve for THC?Both Aleve and Ibuprofen can result in a false positive test for THC. With newer testing methods, we can run confirmatory cross-checks to check for interfering substances, such as metabolites in these medications.

stick312 replied to James Golden, MD's response:

I recently took five urine tests on successive days. I began taking Aleve for tendonitis in my elbow during that time not knowing it might impact the test results. Turns out the last three all tested positive for THC. I contacted Bayer directly and they had no information on file that Aleve would cause a false positive for THC. Where can I get reliable substantiation this could happen?

Report This| Share this:Can Ibuprophen and Naproxen Sodium cause a false positve for THC?I recently took five urine tests on successive days. I began taking Aleve for tendonitis in my elbow during that time not knowing it might impact the test results. Turns out the last three all tested positive for THC. I contacted Bayer directly and they had no information on file that Aleve would cause a false positive for THC. Where can I get reliable substantiation this could happen?

Betty Ford Center

James Golden, MD replied to stick312's response:

This guide from the Mayo Foundation for medical Education and Research offers extensive information that may be helpful:
http://www.mayoclinicproceedings.org/article/S0025-6196(11)61120-8/abstract

Report This| Share this:Can Ibuprophen and Naproxen Sodium cause a false positve for THC?This guide from the Mayo Foundation for medical Education and Research offers extensive information that may be helpful:<br /><a rel="nofollow" href="http://www.mayoclinicproceedings.org/article/S0025-6196(11)61120-8/abstract">http://www.mayoclinicproceedings.org/article/S0025-6196(11)61120-8/abstract</a>

Grundo replied to James Golden, MD's response:

I recently test positive for thc. I don't smoke but I did take naproxen for my back that morning. When the doctor called me to tell me I failed I asked what my level was and he said 47ng. If its under 50 isn't that a negative? Will naproxen give you a false negative? Is there such a thing as a false negative? The doctor from the lab says no way naproxen will give you a false negative. What should I do?

Report This| Share this:Can Ibuprophen and Naproxen Sodium cause a false positve for THC?I recently test positive for thc. I don't smoke but I did take naproxen for my back that morning. When the doctor called me to tell me I failed I asked what my level was and he said 47ng. If its under 50 isn't that a negative? Will naproxen give you a false negative? Is there such a thing as a false negative? The doctor from the lab says no way naproxen will give you a false negative. What should I do?

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