[cowgirlup55]

My stepson's mother tested positive for both cocaine and benzoylecgonine in the hair follicle sample. What is the difference between the 2? The results read as follows:
Cocaines: Positive
Cocaine (GCMS): 2.74 ng/mg Positive
Cocaethylene (GCMS): 0 ng/mg Negative
Benzoylecgonine (GCMS): .95 ng/mg Positive

How is it showing poitive for both cocaine and its metabolite? I thought the half life of cocaine was too short to even show in the hair follicle. Could someone please clarify this for me? And what considered a high/low number in ng/mg for cocaine and benzoylecgonine?
 Miranda

[Donaldson Tan]

Your stepson's mother is most probably a regular consumer of cocaine.

[cowgirlup55]

What woud show that she is a habitual user or regular consumer of cocaine?

[Donaldson Tan]

The presence of coacaine in one's hair sample indicates frequent and regular consumption of coacaine.

[chiralic]

Hello...

Cocaine and metabolites may be detectable in hair for longer periods of time than urine. For this reason, analysis of hair is useful in determining a past history of cocaine use. It takes 4–5 days for ingested cocaine to begin to appear in the hair. The ability to detect cocaine in hair is based more on concentration than a pharmacological “time window” since as long as the hair is not cut, incorporated drug will remain in it.

Many important issues related to hair testing are still being studied including environmental contamination, washing techniques, racial bias in hair based on the concentration of certain types of
melanin, sex bias, specimen adulteration, quality control procedures, proficiency testing and the establishment of cutoff concentrations.

In order to minimize environmental contamination issues and to demonstrate cocaine ingestion, the proposed guidelines for hair testing in federal workplace drug testing programs require a benzoylecgonine/cocaine ratio of > 0.1 in the confirmatory testing process in order to report a positive result

Read more information on these links:
http://www.druglibrary.org/Schaffer/cocaine/cokehair.htm

http://mass-spec.chem.cmu.edu/VMSL/cocaine/ch_bg5.htm

The incorporation of cocaine and metabolites into hair: effects of dose and hair pigmentation
http://dmd.aspetjournals.org/cgi/reprint/28/12/1464.pdf#search=%22Cocaine%20%2BHair%22

If you need more information or need technical advice, please send me a private message

chiralic

[Questionthankyou]

From the research I have gathered, having both Cocaine and the metabolite,  benzoylecgonine confirms a person has used cocaine.  With low levels of Cocaine and without the metabolite, benzoylecgonine, it suggests environmental or external factors.  benzoylecgonine, should be detected longer than Cocaine itself. 

I believe you are looking for Reference Ranges to determine level of usage, timespand or recent usage and frequency.  I am not aware.

[jetman]

Quick question:
I have a pre-employment hair drug test coming up soon, pretty sure they will take leg hair. I stupidly used a small amount of cocaine 14 months ago and do not do any other drugs.. should I be worried??

[billnotgatez]

depends on
 how long the hair is
 how fast your hair grows
 how often the hair falls out for new hair to grow

guys shaving all their hair would send up red flags unless they were Olympic swimmers

[Borek]

guys shaving all their hair would send up red flags unless they were Olympic swimmers

Or bicycle racer. Especially if we are talking about leg shaving.

[jetman]

Ok I dont shave my legs for any reason and wouldnt because I figured it would look suspicious...
That being the case I'm assuming and hoping that my chances are fairly low that it will show up??

[billnotgatez]

one estimate I saw after google was 15 cm per year
any hair longer than that would have traces for sure

[Borek]

one estimate I saw after google was 15 cm per year

This is not that simple, speed of growth is not the only important factor. Compare http://en.wikipedia.org/wiki/Human_hair_growth and http://en.wikipedia.org/wiki/Androgenic_hair. On the legs telogen phase lasts about a year - during this time hair don't grow, they just sit there and don't change (which means they will still contain traces of the metabolites). I guess that's why they prefer leg hair over the head hair.

[qw098]

Great post Borek!

Gotta love how biochemistry can answer important/interesting societal questions!!