Tag: metabolites

THC Metabolite Concentration is Inconsistent Predictor of Impairment

Are blood or saliva concentrations of delta-9 THC metabolites predictive of impairment? That’s what a recent article in the Neuroscience and Biobehavioral Reviews journal sought to determine. The article published data from a meta-regression analysis of 28 studies involving 824 participants. The biggest takeaway is that neither THC nor THC metabolite concentrations are consistent predictors of impairment.  Surprisingly, THC levels in blood, which is the bodily specimen of choice in OWI search warrants in Iowa, showed the weakest correlation. Iowa law equates the mere presence of inactive metabolites of THC with being under the influence of cannabis.  However, the science […]

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Marijuana and Alcohol Combine to Affect Driving Performance

The February 5, 2021 issue of Psychopharmacology published data from a Canadian study assessing the effect of both THC and alcohol on driving performance. Regular users of cannabis participated in simulated driving sessions after smoking marijuana (12.5% THC) and drinking alcohol (target breath alcohol 0.08%). Researchers discovered the driving performance after ingesting both marijuana and alcohol “was significantly greater than the effect of each drug by itself.”  This included the test subjects’ reaction time as well as their ability to maintain speed and lateral position.  The suggested additive effect of marijuana and alcohol on driving performance is consistent with prior […]

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THC Metabolites Detected in Urine Following Full-Spectrum CBD Use

The November 4, 2020 issue of JAMA Psychiatry published results from a recent study examining whether the use of full-spectrum CBD from legal hemp (< 0.30% Δ9-THC) would lead to positive urine test results for THC metabolites. It has been often assumed that hemp-derived cannabidiol products will test negative for urinary THC.  However, the study showed that half of subjects tested positive for carboxy-THC, an inactive metabolite of Δ9-THC, after four weeks of daily use.  Samples were initially screened through urine drug assays.  Positive screens were confirmed through gas chromatography-mass spectroscopy. The results suggest that individuals consistently using full-spectrum, hemp-derived […]

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THC Metabolites Remain in Blood for Extended Periods During Abstinence

According to data recently published in the journal Drug and Alcohol Dependence, THC remained detectable in blood at levels greater than 2.0 ng/ml during several days of abstinence. Investigators affiliated with the University of British Columbia reviewed the relevant literature assessing residual THC plasma levels in those who regularly consume cannabis.  They reported: “[I]n all studies where participants were observed for over a day, blood THC [levels] in some participants remained detectable during several days of abstinence,” with some subjects continuing to test positive for up to 30 days. Some subjects also demonstrated a so-called “double hump” pattern “where their […]

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