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What Causes False Positive Urine Test Result For Cocaine?

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Posted on Tue, 28 Feb 2017
Question: I recently had a urine drug test which came back that I had cocaine in my urine. I was told that my CDL would be suspended and my employer will not let me drive. I suspect I may have taken something over the counter that caused me to fail the test. What may have done that? I do not have any history of illegal drug use .....I do have severe allergies and do use supplements, essential oils and over the counter medications when I have health problems.
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Answered by Dr. Bonnie Berger-Durnbaugh (55 minutes later)
Brief Answer:
Information

Detailed Answer:
Hello XXXXXXX

Antihistamines and decongestants are known to cause false positives on urine drug tests - not specifically for cocaine though. I can't find any data on essential oils and false positives. One substance that can give a false positive for cocaine are anything extracted from coca leaves. I am wondering, if the essential oils came from another country, if they may have had traces of coca leaf in them.

Avoid taking anything (including eating XXXXXXX seeds!) for 1 week prior to a drug test unless you were prescribed it from your doctor. If you do that, it will be documented in the doctor's records.

I recommend you request a follow up test. Not a repeat of the same standard test you just took, but gas chromatography plus mass spectrometry (GC-MS). This is the gold standard test for confirming a positive result on immunoassay. Because false positives do happen, about 5-10% of the time.

I hope this information helps.
Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar
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Answered by
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Dr. Bonnie Berger-Durnbaugh

General & Family Physician

Practicing since :1991

Answered : 3134 Questions

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What Causes False Positive Urine Test Result For Cocaine?

Brief Answer: Information Detailed Answer: Hello XXXXXXX Antihistamines and decongestants are known to cause false positives on urine drug tests - not specifically for cocaine though. I can't find any data on essential oils and false positives. One substance that can give a false positive for cocaine are anything extracted from coca leaves. I am wondering, if the essential oils came from another country, if they may have had traces of coca leaf in them. Avoid taking anything (including eating XXXXXXX seeds!) for 1 week prior to a drug test unless you were prescribed it from your doctor. If you do that, it will be documented in the doctor's records. I recommend you request a follow up test. Not a repeat of the same standard test you just took, but gas chromatography plus mass spectrometry (GC-MS). This is the gold standard test for confirming a positive result on immunoassay. Because false positives do happen, about 5-10% of the time. I hope this information helps.