Alcohol & cannabis - bad mixed use with fatal consequences

Alcohol significantly enhances the effect of cannabis
Since legalization of cannabis in several US states, the question of possible interactions with other legal drugs, in particular alcohol, is increasingly coming to the fore. The US research team led by Marilyn A. Huestis of the National Institute on Drug Abuse in Baltimore has now published a study on the interaction of alcohol and cannabis, with a view to assessing possible impairments also with regard to driving a car.

The mixed consumption of alcohol and cannabis has been a critical issue since the release of the latter in several US states, not least because potential interactions are barely understood so far, the US scientists report in the journal "Clinical Chemistry". In their current study, they have therefore investigated how the combination of tetrahydrocannabinol (THC) and alcohol acts in the organism. They analyzed the evolution of blood THC levels after cannabis use, with and without concurrent low-dose alcohol intake. In combination with the previous alcohol consumption, a significantly higher THC concentration was found.

Combined with alcohol, cannabis has a much stronger effect. (Image: Joshua Resnick / fotolia.com)

THC blood concentration rises through alcohol
Thirty-two adult cannabis smokers initially received either a placebo or a light alcoholic beverage for the study. After ten minutes, they consumed 500 milligrams of cannabis using a vaporiser (vaporizer), with one group receiving high-dose cannabis with a THC concentration of 6.7 percent and the other low-dose with a 2.9 percent concentration. Before and after ingestion, the researchers determined the blood concentration of tetrahydrocannabinol in the subjects. It was found that without alcohol, a maximum concentration of 42.2 micrograms per liter (? G / l) was achieved with the high-dose cannabis and 32.7 g / l in the lower-dose cannabis. In combination with the alcohol, the levels increased to 35.3 micrograms per liter for the low-dose cannabis and as high as 67.5 micrograms for the high-dose.

Mixed consumption drastically increases the risk of accidents
The researchers also view their findings in the context of a recent US Department of Transportation report that the accident risk of cannabis use was 0.7 percent higher, 7.4 percent for alcohol use and 8.4 percent for mixed use, according to the report American Association for Clinical Chemistry. According to study author Marilyn A. Huestis, higher levels of THC could possibly explain the significant increase in performance of a combination of cannabis and alcohol. Recent findings help interpret forensic data and significantly advance the debate on driving under the influence of drugs, the researchers conclude. (Fp)