The effects of alcohol and marijuana in combination: a review

Epidemiological studies indicate that thc (or carboxy thc) is infrequently detected in the blood of dead drivers as the only drug present. In by far the majority of cases these cannabinoids are found in combination with alcohol. Also in the greater proportion of these cases, the BAC is more than 0.1 G per cent, and could itself be a contributory factor in the crash. Either drug alone has been shown to produce impairment of skills performance. When taken together the drug effect is generally one of addition, which most commonly is in the direction of an increase in impairment. There have been several reports which suggest an antagonistic effect exerted by low doses of marijuana on the effects of alcohol. Several reports have indicated that on some behaviours, alcohol and marijuana produce effects which are qualitatively different. Pharmacologically, marijuana and alcohol are distinctly different drugs. At the dose levels used in the studies completed to date, alcohol appears to produce the greater impairment. In all of the studies reported to date, the dose of thc has rarely exceeded 20 mg per subject. In view of the increase in potency of "street" marijuana which has occurred within recent years, it will be necessary to study the effects of higher doses of thc as well as their combination with low to moderate doses of alcohol.


  • English

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 01418231
  • Record Type: Publication
  • Source Agency: ARRB
  • Files: ITRD, ATRI
  • Created Date: Aug 24 2012 6:08AM