عنوان انگلیسی مقاله:
“Residual blood THC levels in frequent cannabis users after over four hours of abstinence: A systematic review.”
ترجمه فارسی عنوان مقاله:
"سطح THC خون باقیمانده در مصرف کنندگان مکرر حشیش بعد از چهار ساعت ممتنع: یک بررسی منظم."
Sciencedirect - Elsevier - Drug and Alcohol Dependence, Journal Pre-proof, 108177. doi:10.1016/j.drugalcdep.2020.108177
Yuan Wei Peng, Ediriweera Desapriya, Herbert Chan, Jeffrey R Brubacher
Background: Tetrahydrocannabinol (THC), the primary psychoactive component of cannabis,
causes psychomotor impairment and puts drivers at increased risk of motor vehicle collisions.
Many jurisdictions have per se limits for THC, often 2 or 5 ng/mL, that make it illegal to drive with
THC above the “legal limit”. People who use cannabis regularly develop partial tolerance to some
of its impairing effects. Regular cannabis users may also have persistent elevation of THC even
after a period of abstinence. Some stakeholders worry that current per se limits may criminalize
unimpaired drivers simply because they use cannabis. We conducted a systematic review of
published literature to investigate residual blood THC concentrations in frequent cannabis users
after a period of abstinence.
Methods: We identified relevant articles by combining terms for “cannabis” and “blood” and
“concentration” and “abstinence” and searching MEDLINE, EMBASE, PsycINFO, and Web of
Science. We included studies that reported THC levels in frequent cannabis users after more than
4 hours of abstinence.
Results: Our search identified 1612 articles of which 8 met our inclusion criteria. After accounting
for duplicate publications, we had identified 6 independent studies. These studies show that blood
THC over 2ng/mL does do not necessarily indicate recent cannabis use in frequent cannabis users.
Five studies reported blood THC >2ng/mL (or plasma THC >3ng/mL) in some participants after six
days of abstinence and two reported participants with blood THC >5ng/mL (or plasma THC
>7.5ng/mL) after a day of abstinence.
Conclusions: Blood THC >2ng/mL, and possibly even THC >5ng/mL, does not necessarily
represent recent use of cannabis in frequent cannabis users.
KEYWORDS: Tetrahydrocannabinol | per se limits | systematic review