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Posted: Tue Jun 26, 2018 10:18 am
by toby
The FDA approved cannabidiol Epidiolex is for treatment of seizures associated with Lennox-Gastaut syndrome and Dravet syndrome. It is from highly-purified, plant-derived CBD. I would doubt it would lead to a marijuana-positive urine and I see that it should not but I cannot find any data on this. Anybody with any hard data?

Re: Cannabidiol

Posted: Tue Jun 26, 2018 3:41 pm
by nehabadheka
That is a good question. Heard that the drug was FDA approved today. I would ask the pharmaceutical directly, GW pharmaceutical.

Re: Cannabidiol

Posted: Wed Jul 04, 2018 8:37 am
by toby
The pharmacy company response "Epidiolex has the potential to produce positive cannabis drug screens. For further information regarding positive drug screens, reference to the specific immunoassay instructions is advised" This does not clear up the picture.

Re: Cannabidiol

Posted: Sun Jul 08, 2018 10:24 am
by Robert Swotinsky MD
Epidiolex is CBD derived from cannabis plants. The use of CBD cannot account for at THCA-positive drug test, as CBD is not THCA and is not metabolized to THCA. See also viewtopic.php?f=1&t=1261 CBD may contain trace amounts of THC. To date, it is not known if those trace amounts are enough to cause positive drug test results.

As a drug derived from cannabis plants, Epidiolex is necessarily a CSA Schedule I drug. My understanding is that the pharmaceutical manufacturer is hopeful that the government will move CBD to Schedule II, so that Epidiolex can be prescribed in the U.S.

If the manufacturer (per toby's post) said Epidiolex may be able to cause positive cannabis screens, then perhaps this is true for the screens, but it is not true for the confirmatory tests unless the Epidiolex contains enough THC as a contaminant to trigger a THCA-positive result. (Non-Epidiolex CBD products are not regulated by FDA, are of course regulated albeit not enforced by DEA, and may contain greater amounts of THC.)

Re: Cannabidiol causing THC UDS positive

Posted: Thu Jul 19, 2018 11:23 am
by edgarcia2
Have a relative who purchased CBD which was "certified" (the 'certificate' was displayed on line) to contain no THC; I decided to perform a POC (Medtox) UDS. Tested positive on one occasion, then stopped the CBD, reverted to negative after several days, restarted CBD, tested positive again. Of course this is only a "study of one" but I am advising employees to use CBD at their own peril; as far as I am concerned, the issue is closed in my mind until I read evidence to the contrary. I tell employees it is not worth losing their job. I quite suspect the positivity is due to small amounts of THC contaminant--not enough to produce psychoactive effects. Though hair testing is not as sensitive for THC, my advice remains the same.

Re: Cannabidiol

Posted: Fri Dec 14, 2018 7:27 pm
by Helent
A notice was sent out by MRO ADVISORY on Nov 26, 2018 by Theodore Shults re: Report of Oral in-vivo Conversion of CBD to delta-9-tetrahydrocannabinol.
This is not relevant to DOT testing where there are DOT rules that guide MRO verifications. This would apply to non-DOT tests.

I have provided a short excerpt from the MRO Advisory below:
Recent unpublished laboratory data and anecdotal reports indicate that a small but not insignificant amount of CBD oil can be converted in vivo to THC. This conversion appears to happen in the stomach due to its acidic environment. (see Chemistry). This issue is actively being studied by SAMHSA/CSAP in conjunction with John Hopkins University. It is also being studied by CBD manufacturers. The CBD-THC conversion appears to be simple and real. It is anticipated this information will quickly go viral and become the standard defense for all positive THC results.
Published documents to-date have indicated that any THCA-positive test result cannot be from use or ingestion of CBD oil. Earlier in this chain, on July 8, Dr. Swotinsky wrote: "The use of CBD cannot account for a THCA-positive drug test, as CBD is not THCA and is not metabolized to THCA."

Now, there is an Advisory that states an unpublished article tells us otherwise.

I am not sure that it is a good idea to verify a test based on unpublished data. There is a recommendation that because many states allow the use of CBD Oil, that a prudent MRO may, if there is no employer policy, report the test "as is" as a "positive lab result". I think it is still reasonable for me to continue to verify claims of ingestion of CBD Oil as a positive test. Especially if the employer's policy addresses and cites federal rules.

Any guidance is greatly appreciated.

Re: Cannabidiol

Posted: Sun Dec 16, 2018 4:06 pm
by Robert Swotinsky MD
I am not sure that it is a good idea to verify a test based on unpublished data.
Researchers have exposed CBC solution to a simulated acidic stomach environment and detected THC after a few hours. The published literature does not indicate that this occurs in real life. An online article describes this concern at To save time, I've cut and pasted the abstract:
Cannabidiol (CBD), a major cannabinoid of hemp, does not bind to CB1 receptors and is therefore devoid of psychotomimetic properties. Under acidic conditions, CBD can be transformed to delta9-tetrahydrocannabinol (THC) and other cannabinoids. It has been argued that this may occur also after oral administration in humans. However, the experimental conversion of CBD to THC and delta8-THC in simulated gastric fluid (SGF) is a highly artificial approach that deviates significantly from physiological conditions in the stomach; therefore, SGF does not allow an extrapolation to in vivo conditions. Unsurprisingly, the conversion of oral CBD to THC and its metabolites has not been observed to occur in vivo, even after high doses of oral CBD. In addition, the typical spectrum of side effects of THC, or of the very similar synthetic cannabinoid nabilone, as listed in the official Summary of Product Characteristics (e.g., dizziness, euphoria/high, thinking abnormal/concentration difficulties, nausea, tachycardia) has not been observed after treatment with CBD in double-blind, randomized, controlled clinical trials. In conclusion, the conversion of CBD to THC in SGF seems to be an in vitro artifact.
The MRO standard of practice is based on the published scientific literature, MRO training materials, federal guidelines, and (last and least) MRO newsletters and the like. I'm told that those who write MRO newsletters may be prescient, but also sometimes print things that turn out to be incorrect. I'd stay tuned...

Re: Cannabidiol

Posted: Sun Dec 16, 2018 5:05 pm
by Helent
Thank you for your opinion regarding unpublished data, and your reference to the online article. This is very helpful.

Re: Cannabidiol

Posted: Fri Jun 28, 2019 12:16 pm
by gamecockmd
Our local community -- like most others -- is currently overrun with retailers offering CBD oil for ingestion for a plethora of conditions. Our state health agency tested these CBD oil products and found 60% of them were not pure cannabidiol and contained up to 0.9% THC. Our health system randomly performs UDS's and on occasion, the screen is "non-negative" for THC and the GC/MS quantitative result is >=20 ng/ml.

The donor in such a case absolutely denies any active marijuana exposure and has clear evidence of regular CBD oil ingestion (often on the advice of a clinician) as the offered explanation of the non-negative result.

Should we accept this a valid result, or insist that the >=20 ng/ml is positive for marijuana which is illegal in our state?

Thanks for comments and advice!

Re: Cannabidiol

Posted: Fri Jun 28, 2019 5:42 pm
by Robert Swotinsky MD
The MRO review is based on whether or not the donor has a legitimate medical explanation in the context of applicable drug testing regulations and guidelines, e.g., the HHS Guidelines, the DOT Procedures. The DOT rule [49 CFR ยง40.151(d)] and the SAMHSA Medical Review Officer Manual instruct the MRO to not downgrade positive drug test results based on claims that they were caused by unknowing consumption of the drugs. MROs are unlikely to be able to verify the facts of unknowing ingestion explanations. Furthermore, such use is outside the context of prescribed medical care - a physician cannot prescribe CBD oil or THC, as prescribing is a federally regulated process and neither CBD oil or THC are prescription products - and is therefore not a legitimate medical explanation. In nonregulated testing, MROs invariably follow the federal lead and reject such explanations.