Toxicology Rounds: Five Myths about Marijuana Tests

Job applicants are failing pre-employment drug screenings in record numbers, and some Colorado companies say 90 percent of their prospective employees at times have to be rejected because they fail drug tests. The most rapid increase involved positive tests for marijuana that went up 25 percent between 2012 and 2016.

This explosion in positive marijuana tests is important for emergency practitioners from clinical and occupational medicine perspectives. The prerequisite for making medically and scientifically sound decisions based on these tests is detailed knowledge of how cannabinoids are metabolized and eliminated by the body.

THC is the primary psychotropic component of cannabis. It is converted by the hepatic P450 system into 11-OH-THC, an active metabolite similar to THC in its psychotropic effects, potency, and kinetics. 11-OH-THC is a significant contributor to the mind-altering effects of cannabis, especially after ingesting edible products when THC gets absorbed from the gastrointestinal tract and a large proportion goes directly to the liver. FULL ARTICLE