Extended plasma cannabinoid excretion in chronic frequent cannabis smokers during sustained abstinence and correlation with psychomotor performance

Complexity of Translating Analytics to Recent Cannabis Use and Impairment

While current analytical methodologies can readily identify cannabis use, definitively establishing recent use within the impairment window has proven to be far more complex, requiring a new approach. Recent studies have shown no direct relationship between impairment and Δ9-tetra-hydrocannabinol (Δ9-THC) concentrations in blood or saliva, making legal "per se" Δ9-THC limits scientifically unjustified. Current methods that focus on Δ9-THC and/or metabolite concentrations in blood, saliva, urine, or exhaled breath can lead to false-positive results for recent use due to the persistence of Δ9-THC well outside of the typical 3-4 h window of potential impairment following cannabis inhalation. There is also the issue of impairment due to other intoxicating substances-just because a subject exhibits signs of impairment and cannabis use is detected does not rule out the involvement of other drugs. Compounding the matter is the increasing popularity of hemp-derived cannabidiol (CBD) products following passage of the 2018 Farm Bill, which legalized industrial hemp in the United States. Many of these products contain varying levels of Δ9-THC, which can lead to false-positive tests for cannabis use. Furthermore, hemp-derived CBD is used to synthesize Δ8-THC, which possesses psychoactive properties similar to Δ9-THC and is surrounded by legal controversy. For accuracy, analytical methods must be able to distinguish the various THC isomers, which have identical masses and exhibit immunological cross-reactivity. A new testing approach has been developed based on exhaled breath and blood sampling that incorporates kinetic changes and the presence of key cannabinoids to detect recent cannabis use within the impairment window without the false-positive results seen with other methods. The complexity of determining recent cannabis use that may lead to impairment demands such a comprehensive method so that irresponsible users can be accurately detected without falsely accusing responsible users who may unjustly suffer harsh, life-changing consequences.

Unlocking the Healing Potential: Cannabinoids in Spine Surgery for Pain Relief and Recovery

» Cannabinoids, such as D9-tetrahydrocannabinol and cannabidiol, interact with endocannabinoid receptors in the central nervous system and immune system, potentially offering pain relief. The entourage effect, resulting from the interaction of multiple cannabis components, may enhance therapeutic impact and efficacy, making them promising candidates for exploring pain relief in spine operations, known to be among the most painful operative procedures.» The use of cannabinoids in pain management requires careful consideration of safety, including their cognitive and psychomotor effects, potential cardiovascular risks, risk of dependence, mental health implications, and drug interactions.» Few studies have analyzed cannabinoid use in relation to spine surgery, with variable results reported, indicating possible effects on reoperation rates, mortality, complications, postoperative opioid use, and length of hospital stay.» Current knowledge gaps exist in the understanding of cannabinoid effects on spine surgery, including the exploration of different administration routes, timing, dosage, and specific outcomes. In addition, mechanistic explanations for the observed results are lacking.» Ethical considerations related to informed consent, medical expertise, societal impact, and legal compliance must also be thoroughly addressed when considering the utilization of cannabinoids in spinal pathologies and back pain treatment.

Effect of vaporizing cannabis rich in cannabidiol on cannabinoid levels in blood and on driving ability - a randomized clinical trial

The aim of this prospective, placebo-controlled, double-blind, randomized, cross-over study was to determine cannabinoid levels in blood and driving-related ability after single (S1) and repetitive (S2) vaporization of cannabis rich in cannabidiol (CBD) containing < 1% Δ9-etrahydrocannabinol (THC). Healthy adult volunteers (Nsingle = 27, Nrepetitive = 20) with experience in smoking vapor-inhaled two low-THC/CBD-rich cannabis products both with < 1% THC (product 1: 38 mg CBD, 1.8 mg THC; product 2: 39 mg CBD, 0.6 mg THC) and placebo. Main outcomes were THC- and CBD-levels in whole blood and overall assessment of driving-related ability by computerized tests. Among 74 participants included, 27 (mean age ± SD, 28.9 ± 12.5 years) completed S1, and 20 (25.2 ± 4.0) completed S2. Peak concentrations and duration of detectability depended on the THC-content of the product. After single consumption THC dropped below 1.5 µg/L after 1.5 h, but was detected in some participants up to 5 h. Pairwise comparison of driving-related ability revealed no significant differences between low-THC/CBD-rich products (P1, P2) and placebo. Detection of THC after consumption of low-THC/CBD-rich cannabis might have legal consequences for drivers. Regarding overall driving-related ability, no significant differences were observed between the interventional products. This trial was registered with the German Clinical Trials Register (DRKS00018836) on 25.10.2019 and with the Coordination Office for Human Research (kofam) which is operated by the Federal Office of Public Health (FOPH) (SNCTP000003294).

Effects of High-Potency Cannabis on Psychomotor Performance in Frequent Cannabis Users

Background: Recently increased access to cannabis products in the United States has been associated with increased rates of driving after cannabis use. Although numerous studies indicate that cannabis impairs psychomotor and neurocognitive functions that can affect driving ability, the determination of cannabis-impaired driving risk is complicated by the extent to which frequent cannabis users develop tolerance to THC's subjective, cognitive, and psychomotor effects, and by the fact that there is no validated behavioral or biological marker of recent cannabis use or cannabis-related impairment. This study examined the psychomotor impairment-related effects experienced by frequent cannabis users in Colorado after naturalistic consumption of smoked cannabis, both immediately and 1 h postuse. Results were then validated in a smaller replication sample from Washington state. Methods: In the primary Colorado study, participants (n=70) used the DRUID^® mobile app, a brief measure of psychomotor and cognitive domains that are sensitive to the effects of cannabis. First, participants used DRUID to establish a sober baseline impairment score. During a second appointment, they used DRUID at three time points: preuse, immediately after acutely using cannabis, and 1 h postuse. In the Washington replication sample, participants (n=39) used DRUID before acute cannabis consumption and then every half hour for 2.5 h. Results: In both studies, peak DRUID impairment effects were seen immediately after cannabis use, with recovery of performance at 1 h postuse. Specifically, significant quadratic effects of time emerged for both studies (Colorado study: (β=-0.935, SE=0.204, p<0.001); Washington study: β=3.0299, SE=1.3085, p<0.01). Domain-specific effects were tested in the larger Colorado study and were observed for reaction time within a complex divided attention task and a postural-stability balance task. Conclusions: These findings demonstrate that psychomotor impairment emerges immediately after acute cannabis use even in regular users, but decreases significantly 1 h postuse. These results underscore the potential utility of the DRUID app for assessing acute cannabis-related psychomotor impairment. Further research is needed to explore whether the DRUID app and/or the specific psychomotor functions it assesses might serve as a tool for measuring cannabis-related driving impairment. Clinical trials registration number for the Colorado Study: NCT03522103.

Local Anesthetic Efficacy in Marijuana Users and Nonusers: A Pilot Study

OBJECTIVE

Despite the common clinical impression that patients with a history of drug use are challenging to anesthetize with local anesthesia, literature on this clinical phenomenon is sparse. The objective of this pilot study was to assess if differences in local anesthetic efficacy for dental treatment exist between marijuana users and nonusers.

METHODS

Subjects were healthy adult males and females who qualified as either chronic marijuana users or nonusers. All subjects had an asymptomatic, vital maxillary lateral incisor that responded to an electric pulp test (EPT). A standard maxillary infiltration injection technique was employed using 1.7 mL 2% lidocaine with 1:100,000 epinephrine over the test tooth, and the tooth was tested with an EPT at 3-minute intervals.

RESULTS

A total of 88% of nonusers (15/17) and 61% of users (11/18) were successfully anesthetized, defined as anesthesia onset within 10 minutes and lasting at least 15 minutes. The difference in the proportion of anesthetized subjects was not statistically significant (P = .073). For subjects with successful anesthesia, there was no significant difference between nonusers and users in the onset or duration of anesthesia.

CONCLUSION

No significant differences in local anesthetic efficacy with respect to local anesthetic success, onset, or duration of action were found between chronic marijuana users and nonusers. However, larger studies are likely needed to provide more definitive evidence.

A comprehensive breath test that confirms recent use of inhaled cannabis within the impairment window

Legalization of cannabis for medicinal and/or recreational use is expanding globally. Although cannabis is being regulated country by country, an accurate recent use test with indisputable results correlated with impairment has yet to be discovered. In the present study, a new approach for determining recent cannabis use within the impairment window after smoking was developed by studying 74 subjects with a mean age of 25 years and average use history of 9 years. Horizontal gaze nystagmus was evaluated along with subject self-assessments of impairment, and blood and breath samples were collected before and after smoking cannabis. Breath and blood pharmacokinetic parameters and cannabinoid profiles determined recent use within the impairment window. No subjects were positive for recent use pre-smoking, although all subjects had detectable cannabinoids in breath samples. We describe an inhaled cannabis recent use test that correlates with impairment and helps protect against wrongful prosecution and workplace discrimination.

Cannabis and Driving

As more states in the U.S legalize recreational and medicinal cannabis, rates of driving under the influence of this drug are increasing significantly. Aspects of this emerging public health issue potentially pit science against public policy. The authors believe that the legal cart is currently significantly ahead of the scientific horse. Issues such as detection procedures for cannabis-impaired drivers, and use of blood THC levels to gauge impairment, should rely heavily on current scientific knowledge. However, there are many, often unacknowledged research gaps in these and related areas, that need to be addressed in order provide a more coherent basis for public policies. This review focuses especially on those areas. In this article we review in a focused manner, current information linking cannabis to motor vehicle accidents and examine patterns of cannabis-impairment of driving related behaviors, their time courses, relationship to cannabis dose and THC blood levels, and compare cannabis and alcohol-impaired driving patterns directly. This review also delves into questions of alcohol-cannabis combinations and addresses the basis for of per-se limits in cannabis driving convictions. Finally, we distinguish between areas where research has provided clear answers to the above questions, areas that remain unclear, and make recommendations to fill gaps in current knowledge.

Population pharmacokinetic model of blood THC and its metabolites in chronic and occasional cannabis users and relationship with on-site oral fluid testing

AIMS

To develop a population pharmacokinetic (PP) model of delta-9-tetrahydrocannabinol (THC) and its metabolites in blood and to determine the relationship between blood THC pharmacokinetics and results of on-site oral fluid (OF) testing in chronic (CC) and occasional (OC) cannabis users.

METHODS

Fifteen CC (1-2 joints/day) and 15 OC (1-2 joints/week) aged 18-34 years were included, genotyped for their CYP2C9 polymorphisms. Twelve measurements of blood THC, 11-OH-THC and THC-COOH were carried out during the 24-hour period after controlled cross-over random inhalation of placebo, 10 mg or 30 mg of THC. OF tests (DrugWipe® 5S) were performed up to 6 hours and then stopped after two successive negative results. The blood concentrations and their relationship to OF testing results were analysed using a PP approach with NONMEM® and R.

RESULTS

A three-compartment model described the pharmacokinetics of THC, with zero-order absorption, and a two-compartment model the metabolites. The fraction of THC converted to 11-OH-THC was 0.27 and the fraction of 11-OH-THC to THC-COOH was 0.86. Smoking 30 mg of THC decreased the THC bioavailability to 0.68 compared to 10 mg. CC showed a 2.41 greater bioavailability than OC, leading to higher C_max and AUC for the three compounds for the same dose. The best model describing the probability of a positive OF test included THC blood concentration and the group as covariate: for a similar THC blood concentration, a CC was less likely to be positive than an OC.

CONCLUSION

OC are more likely to screen positive than CC for a similar blood concentration.

Is the Urine Cannabinoid Level Measured via a Commercial Point-of-Care Semiquantitative Immunoassay a Cannabis Withdrawal Syndrome Severity Predictor?

Background: For cannabis-dependent subjects, the relationship between cannabis withdrawal syndrome (CWS) severity and the urine cannabinoid concentrations are unclear; we investigated this using a commercial point-of-care (POC) enzyme immunoassay detecting 11-nor-9-carboxy-Delta-9-tetrahydrocannabinol (THC-COOH). Methods: Observational study of 78 adult chronic cannabis-dependent subjects assessed over a 24-day inpatient detoxification treatment, with 13 serial measurement days. Repeated Measures Correlation and Multilevel Linear Models were employed. Results: Absolute urinary THC-COOH levels significantly correlated with Marijuana Withdrawal Checklist (MWC) scores across the entire study duration (r = 0.248; p < 0.001). Correlation between serial creatinine-adjusted THC-COOH ratios and serial MWC scores emerged as significant only in the sample with higher MWC scores (>11 points) at admission (n = 21; r = 0.247; p = 0.002). The aforementioned significant relationships have persisted when replacing the absolute THC-COOH-levels with the (relative) day-to-day change in urinary THC-COOH levels. MWC scores were significantly correlated with the Clinical Global Impression-Severity (CGI-S; r = 0.812; p < 0.001). Females showed a significantly slower decline in urine THC-COOH levels and prolonged CWS course characterized by substantial illness severity (per CGI-S), occurring in nearly 30% of cases. Conclusion: Urine cannabinoid levels (THC-COOH) determined by POC assay significantly predicted CWS severity (moderate correlation), guiding detoxification treatment duration. In patients with MWC > 11 points upon admission, creatinine-adjusted THC-COOH ratios also significantly predicted CWS severity-again with moderate effect size. Females showed prolonged urinary THC-COOH elimination and cannabis withdrawal.

"Residual blood THC levels in frequent cannabis users after over four hours of abstinence: A systematic review."

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 h 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 2 ng/mL does do not necessarily indicate recent cannabis use in frequent cannabis users. Five studies reported blood THC >2 ng/mL (or plasma THC >3 ng/mL) in some participants after six days of abstinence and two reported participants with blood THC >5 ng/mL (or plasma THC > 7.5 ng/mL) after a day of abstinence.

CONCLUSIONS

Blood THC >2 ng/mL, and possibly even THC >5 ng/mL, does not necessarily represent recent use of cannabis in frequent cannabis users.

Epidemiology of drug driving: protocol from a national Canadian study measuring levels of cannabis, alcohol and other substances in injured drivers

Background

Drug driving is an emerging global road safety problem. As the prevalence of alcohol-impaired driving decreases, and as more jurisdictions decriminalize or legalize cannabis, it is increasingly important for policy makers to have accurate information on the prevalence and pattern of drug driving. Unfortunately, this data is not widely available and the World Health Organization identifies lack of accurate data on the prevalence of drug driving as an important knowledge gap.

Methods

In this paper, we discuss the limitations of current methods of monitoring drug use in drivers. We then present a novel methodology from a multi-centre study that monitors the prevalence and pattern of drug use in injured drivers across Canada. This study uses “left-over” blood taken as part of routine medical care to quantify cannabis and other drugs in non-fatally injured drivers who present to participating emergency departments after a collision. Toxicology testing is done with waiver of consent as we have procedures that prevent results from being linked to any individual. These methods minimize non-response bias and have the advantages of measuring drug concentrations in blood obtained shortly after a collision.

Discussion

Our methods can be applied in other jurisdictions and provide a consistent approach to collect data on drug driving. Consistent methods allow comparison of drug driving prevalence from different regions. Data from this research can be used to inform policies designed to prevent driving under the influence of cannabis and other impairing drugs.

Δ9-tetrahydrocannabinol (THC) is present in the body between smoking sessions in occasional non-daily cannabis users

BACKGROUND

THC can be measured in blood up to a month after last intake in heavy cannabis users. The cognitive deficits during abstinence have been hypothesized to be at least in part due to residual THC in brain. To which extent THC accumulation will occur after occasional cannabis use has gained limited attention. We aimed to predict THC-levels between smoking sessions in non-daily as well as daily cannabis users and to compare these predictions with published THC levels.

METHODS

Predictions were based on pharmacokinetic principles on drug accumulation after repeated dosing, applied to different cannabis smoking patterns, using data from a three-compartment model for THC pharmacokinetics and results on the terminal elimination half-life of THC in humans. We searched the literature for THC measurements which could be compared with these predictions. We found no such results from controlled studies of long-term repeated cannabis consumption of known THC amounts. Thirteen published studies contained, however, enough information on cannabis use and results from THC-measurements to make tentative comparisons with the predictions.

RESULTS

The predictions of THC-plasma levels present after different cannabis smoking patterns assuming terminal elimination half-lives of THC of 21.5 h or longer, had some support in published THC levels measured in individuals self-reporting their cannabis consumption. We found no consistent discrepancies between the predictions and reported THC plasma levels after non-daily or daily cannabis use. The predictions indicate that THC might be present in plasma between smoking sessions above usual analytical limits when smoking every third and second day, and at lower levels after once weekly smoking.

CONCLUSIONS

The study indicates that THC might be present continuously even in non-daily smokers at low levels, even if the smoking occasions are separated by a week. This is different from alcohol, where ethanol has disappeared after a day. From a toxicological point of view the persistance of THC in the brain, raises questions whether this should be given more attention as with other toxicological thinking where long-term presence of bioactive substances gives rise to concern. There are some uncertainties in this analysis, and controlled studies on THC-accumulation accompanying different use patterns seem warranted.

Cannabis use as a risk factor for causing motor vehicle crashes: a prospective study

AIM

We conducted a responsibility analysis to determine whether drivers injured in motor vehicle collisions who test positive for Δ-9-tetrahydrocannabinol (THC) or other drugs are more likely to have contributed to the crash than those who test negative.

DESIGN

Prospective case-control study.

SETTING

Trauma centres in British Columbia, Canada.

PARTICIPANTS

Injured drivers who required blood tests for clinical purposes following a motor vehicle collision.

MEASUREMENTS

Excess whole blood remaining after clinical use was obtained and broad-spectrum toxicology testing performed. The analysis quantified alcohol and THC and gave semiquantitative levels of other impairing drugs and medications. Police crash reports were analysed to determine which drivers contributed to the crash (responsible) and which were 'innocently involved' (non-responsible). We used unconditional logistic regression to determine the likelihood (odds ratio: OR) of crash responsibility in drivers with 0 < THC < 2 ng/ml, 2 ng/ml ≤ THC < 5 ng/ml and THC ≥ 5 ng/ml (all versus THC = 0 ng/ml). Risk estimates were adjusted for age, sex and presence of other impairing substances.

FINDINGS

We obtained toxicology results on 3005 injured drivers and police reports on 2318. Alcohol was detected in 14.4% of drivers, THC in 8.3%, other drugs in 8.9% and sedating medications in 19.8%. There was no increased risk of crash responsibility in drivers with THC < 2 ng/ml or 2 ≤ THC < 5 ng/ml. In drivers with THC ≥ 5 ng/ml, the adjusted OR was 1.74 [95% confidence interval (CI) = 0.59-6.36; P = 0.35]. There was significantly increased risk of crash responsibility in drivers with blood alcohol concentration (BAC) ≥ 0.08% (OR = 6.00;95% CI = 3.87-9.75; P < 0.01), other recreational drugs detected (OR = 1.82;95% CI = 1.21-2.80; P < 0.01) or sedating medications detected (OR = 1.45; 95%CI = 1.11-1.91; P < 0.01).

CONCLUSIONS

In this sample of non-fatally injured motor vehicle drivers in British Columbia, Canada, there was no evidence of increased crash risk in drivers with Δ-9-tetrahydrocannabinol < 5 ng/ml and a statistically non-significant increased risk of crash responsibility (odds ratio = 1.74) in drivers with Δ-9-tetrahydrocannabinol ≥ 5 ng/ml.

Dark Classics in Chemical Neuroscience: Δ9-Tetrahydrocannabinol

Cannabis ( Cannabis sativa) is the most widely used illicit drug in the world, with an estimated 192 million users globally. The main psychoactive component of cannabis is (-)- trans-Δ⁹-tetrahydrocannabinol (Δ⁹-THC), a compound with a diverse range of pharmacological actions. The unique and distinctive intoxication caused by Δ⁹-THC primarily reflects partial agonist action at central cannabinoid type 1 (CB₁) receptors. Δ⁹-THC is an approved therapeutic treatment for a range of conditions, including chronic pain, chemotherapy-induced nausea and vomiting, and multiple sclerosis, and is being investigated in indications such as anorexia nervosa, agitation in dementia, and Tourette's syndrome. It is available as a regulated pharmaceutical in products such as Marinol, Sativex, and Namisol as well as in an ever-increasing range of unregistered medicinal and recreational cannabis products. While cannabis is an ancient medicament, contemporary use is embroiled in legal, scientific, and social controversy, much of which relates to the potential hazards and benefits of Δ⁹-THC itself. Robust contemporary debate surrounds the therapeutic value of Δ⁹-THC in different diseases, its capacity to produce psychosis and cognitive impairment, and the addictive and "gateway" potential of the drug. This review will provide a profile of the chemistry, pharmacology, and therapeutic uses of Δ⁹-THC as well as the historical and societal import of this unique, distinctive, and ubiquitous psychoactive substance.

Effect of Smoked Cannabis on Vigilance and Accident Risk Using Simulated Driving in Occasional and Chronic Users and the Pharmacokinetic-Pharmacodynamic Relationship

BACKGROUND

The pharmacokinetic-pharmacodynamic relationship between whole blood δ-9-tetrahydrocannabinol (THC) and driving risk is poorly understood.

METHODS

Fifteen chronic cannabis consumers (1-2 joints/day; CC) and 15 occasional cannabis consumers (1-2 joints/week; OC) of 18 to 34 years of age were included. A pharmacokinetic study was conducted with 12 blood samplings over a 24-h period before and after controlled random inhalation of placebo or 10 mg or 30 mg of THC. THC and metabolites were quantified using LC-MS/MS. Effects on reaction time by psychomotor vigilance tests and driving performance through a York driving simulator were evaluated 7 times. A pharmacokinetic-pharmacodynamic analysis was performed using R software.

RESULTS

Whole blood peak THC was 2 times higher in CC than in OC for a same dose and occurred 5 min after the end of consumption. THC remained detectable only in CC after 24 h. Despite standardized consumption, CC consumed more available THC from each cigarette regardless of dose. Maximal effect for reaction time was dose- and group-dependent and only group-dependent for driving performance, both being decreased and more marked in OC than in CC. These effects were maximal around 5 h after administration, and the duration was longer in OC than in CC. A significant pharmacokinetic-pharmacodynamic relationship was observed only between T _max for blood THC and the duration effect on mean reciprocal reaction time.

CONCLUSIONS

Inhalation from cannabis joints leads to a rapid increase in blood THC with a delayed decrease in vigilance and driving performance, more pronounced and lasting longer in OC than in CC. ClinicalTrials.gov Identifier: NCT02061020.

Coronary thrombosis and marijuana smoking: a case report and narrative review of the literature

We encountered evidence of myocardial infarction due to coronary thrombosis in an autopsy of an occasional marijuana smoker. These findings prompted us to perform a narrative review of the literature to determine when post-mortem toxicological tests may support a temporal relationship between marijuana smoking and cardiovascular disease. Toxicological examination showed the presence of Δ-9-tetrahydrocannabinol, its main metabolite and cannabinol in blood and urine. Quali-quantitative analysis revealed that Δ-9-tetrahydrocannabinol was taken within 2 h of the onset of cardiovascular symptoms, according to circumstantial data. Post-mortem toxicological results must take into account the degradation and post-mortem redistribution of analytes. However, for any inference about the specific cardiovascular triggering effect of Δ-9-tetrahydrocannabinol intake, we maintain that cannabinoid analysis in blood samples must be considered an essential requirement to estimate the time of last intake and avoid incomplete documentation. The literature, combined with the present case report, highlights an association between marijuana use and negative cardiovascular events, although few authors have supported their conclusions with toxicological results. Thus, additional research is needed.