How Can You Test Positive For Cocaine But Not Benzoylecgonine?

Posted on Mon, 22 Jul 2013

Medically reviewed by Ask A Doctor - 24x7 Medical Review Team

Mon, 22 Jul 2013 Answered on

Tue, 20 Aug 2013 Last reviewed on

Question : how can you test posiotive for cocaine but not benzoylecgonine

Answered by Dr. Jay Patel (1 hour later)

Hi,

Based on the information provided you are wanting to know is their a way to test positive for cocaine and not for benzoylecgonine.

I am dr XXXXXXX and I will try my level best of help you.

Its not possible to do so, benzoylecgonine is break down product of cocaine (the way how liver breaks cocaine into benzoylecgonine is known as metabolism) and the urine test which test for drug screening is searching for the benzoylecgonine component. Hence its impossible to test negative for drugs, if you are taking benzoylecgonine.

Hope it helps, please feel free to contact me in case of further clarification.

Thanks for the query.
Dr. XXXXXXX XXXXXXX

Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar

Follow up: Dr. Jay Patel (32 minutes later)

I am having to do mouth swab drug testing for probation and had a test come back positive for Cocaine (84ng/ml). Yet negative for benzoylecgonine. I have not done any cocaine, so I am questioning how I can show positive for cocaine without showing positive for the cocaine metabolite benzoylecgonine.

Answered by Dr. Jay Patel (1 hour later)

Hi,

Welcome back, their 8 metablolites of cocaine viz.
1) benzoylecgonine (BZE),
2) ecgonine methylester (EME),
3) norcocaine (NCOC),
4) benzoylnorecgonine (BNE),
5) m-hydroxy-BZE (m-HO-BZE),
6) p-hydroxy-BZE (p-HO-BZE),
7) m-hydroxy-COC (m-HO-COC), and
8) p-hydroxy-COC (p-HO-COC).

So if you take benzoylecgonine which comes in drug form for pain, it will change to successive metabolite so may not test positive for that metabolite, but will be tracked for other 7 and presence of any one is still consider positive of cocaine.

Hope it makes it bit clear. Please contact me in case of further clarifications.

Thanks again.
Dr XXXXXXX XXXXXXX

Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar