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Ask Dr. D. Love Your Own Question
Dr. D. Love
Dr. D. Love, Doctor
Category: Drug Testing
Satisfied Customers: 19443
Experience:  Family Physician for 10 years; Hospital Medical Director for 10 years.
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I recently failed a drugs test in work it came up positive

Customer Question

hi, I recently failed a drugs test in work it came up positive for cocaine at 420ng/ml. I work as a doorman on the weekends and have frequent contact with this drug by holding, confiscating, wiping the powder off surfaces, users spitting saliva and blood at me etc. I did some calculations with the half life etc and I worked out that all that needed to be in my system was 0.02 of a gram for me to have failed at that amount. I have also researched case studies where people have failed from being in contact with it at greater level than what was in my urine. my work has came back and has said that it is unlikely the level could of come back from what I am saying and that the amount I took is sufficient enough to get a buzz. I am just after some expert advice on this
Submitted: 2 years ago.
Category: Drug Testing
Expert:  Dr. D. Love replied 2 years ago.
Hello from JustAnswer.
Was this the level of cocaine or the metabolite, benzoylecgonine?
Customer: replied 2 years ago.
Expert:  Dr. D. Love replied 2 years ago.
Thank you for the clarification. That is the usual substance that is measured in the urine. If this was a cocaine level, then I would have wanted to confirm that is was a urine level and not a blood level.
There are several comments that are pertinent in this situation.
First, the amount of cocaine or benzoylecgonine in the urine cannot be used to determine the amount of the drug that has entered the system. The drug and metabolite concentration is affected by many other factors, particularly factors that affect hydration and urine flow.
There is some logic in using the half-life when analyzing blood levels. But even blood levels of cocaine, by themselves, are not able to be used to determine the amount of drug that was ingested. It would also require knowledge of when the drug was taken relative to the time the level was checked. Any given blood level can occur from a more recent lower dose or a more distant higher dose.
So, the question in this case is whether there could be sufficient exposure at work to cause a benoylecgonine concentration in the urine of 420 ng/ml. There are no studies that show that a urine concentration at this level can be achieved from the type of occupational exposure that you describe. There is evidence that occupational exposure to large amounts of the drug can achieve this level, such as crime lab personnel. But someone working as a doorman would not be exposed to this level of the drug. There is no clinical evidence that there is sufficient exposure by working as a doorman to achieve this level of benoylecgonine.
If there is this level of benzoylecgonine and you have not been using the drug, the first concern would be that you have been given the drug surreptitiously, rather than occupational exposure.
If I can provide any clarification, please let me know.
Customer: replied 2 years ago.
Thanks for getting back to me and I understand what your saying but ive got a case study of a person who put 0.005g on his forearm and showed up for 55ng/ml 48hrs later and a crime lab personel showed up as 1570ng/ml
I agree i dont handle kg of the stuff but i do catch a lot of people with it and stupidly i wipe the surfaces down with the palm of my hand and run my finger across the bottom of the cards to pick up any powder left on it..
Could it of gotten through say a cut on my hand? I initially thought about someone putting it into my drink but i cant see why that would benefit someone and its too expensive to waste.
I know users to take it reguarly and they on average do about 3 grams each time they take it. Now when ive researched people failing tests after admitting doing the drug there levels have came back greater than 2500..
Customer: replied 2 years ago.
P.s i worked the saturday night and failed the test around 3pm on the tuesday
Expert:  Dr. D. Love replied 2 years ago.
I am sorry for the delay, but I was away from the computer when you responded.
There are no studies that show that the type of exposure that you describe will cause this level of benzoylecgonine in the urine.
Admittedly, it is impractical to perform studies that look at every possible permutation of exposure, such as whether it could have entered the system through a cut. The closest that could be said to address that hypothetical situation would be the fact that there are no reports of employers of doormen that perform drug testing seeing any significant number of employees becoming positive.