Canadian researchers have uncovered metabolic ‘fingerprints’ predicting medicinal cannabis impairment in a study which could have profound implications for roadside drug-driving tests.

The team discovered signature metabolites — like fingerprints in the blood — linked to the cognitive dysfunction and impaired motor skills associated with medicinal cannabis use.

Male rats were given medicinal cannabis oil with and without THC, or oil with no cannabis. Then their behaviour was observed and blood samples examined for a correlation in the metabolites — substances produced when the body breaks down food, drugs or tissues such as fat or muscle.

Those treated with oil containing THC had lower levels of butyric acid, a microbial byproduct of digestion, in their blood. The next step will be to examine whether butyric acid or sodium butyrate supplements could be effective in reducing impairment when taken with medicinal cannabis.

Not only could the discovery lead to better roadside blood tests for impairment, it could indicate supplements or strains of medicinal cannabis that reduce impairment while preserving pain management benefits, according to principal investigator Jason Dyck.

He said: “We wanted to see if there is a metabolic fingerprint in the serum that identifies if a person is cognitively impaired when they take cannabis.” 

“We found metabolites that were changed in the same direction that we see in studies of cognitive impairment from other conditions. There seems to be a fingerprint that is more predictive of cognitive impairment than just looking at THC levels alone.”

Dyck, professor in the Faculty of Medicine and Dentistry, director of the Cardiovascular Research Centre, and Canada Research Chair in Molecular Medicine, said the discovery could help pain patients taking medicinal cannabis who are unhappy with the accompanying cognitive dysfunction.

“Sure, you’re managing your pain, but cognitive impairment means you can’t drive a car, you can’t work and your daily life may be severely affected,” he added.

Prior to launching Cannabiz, Martin was co-founder and CEO of Asia-Pac’s leading B2B media and marketing information brand Mumbrella, overseeing its sale to Diversified Communications in 2017. A journalist...