Metabolism, disposition, and kinetics of delta-9-tetrahydrocannabinol in men and women

Evaluation of Cannabis Per Se Laws: A Semi-Mechanistic Pharmacometrics Model for Quantitative Characterization of THC and Metabolites in Oral Users

Recreational cannabis use has increased notably in the United States in the past decade, with a recent surge in oral consumption. This trend has raised concerns about driving under the influence. Current cannabis-impaired driving laws lack standardization, with some states implementing blood Δ9-tetrahydrocannabinol (THC) per se limits (1, 2, and 5 ng/mL). However, these limits have been criticized for their inaccuracy and unreliability, highlighting the need for legal refinement. Addressing this issue requires understanding the complex pharmacokinetics (PK) and pharmacodynamics (PD) of THC, cannabis's primary psychoactive component, which can be characterized using a population PK model. However, existing PK models mainly focus on inhalation data and do not account for the growing number of oral cannabis users. To bridge this gap, a semi-mechanistic population PK model was developed using data from 10 published studies following intravenous or oral administration of cannabis to characterize THC and its metabolites in oral users. Simulated THC plasma concentrations for doses from 2.5 mg to 100 mg in frequent and occasional users were used to evaluate the effectiveness of existing per se limits. Results showed that the 1 ng/mL limit was least effective due to a high risk of false positives, while the 2 and 5 ng/mL limits remain inconclusive due to limited PD data linking blood THC levels to impairment. These findings suggest that the existing per se laws may not fully address the complexity of cannabis impairment, underscoring the need for further research and refinement of cannabis-impaired driving laws.

High Stakes: Exploring the Impact of Cannabis Use in Pregnancy and Lactation

Cannabis is the most commonly used federally illicit substance during pregnancy in the United States, with an estimated prevalence of 3% to 30%. The American College of Obstetricians and Gynecologists and the American Academy of Pediatrics discourage cannabis use during pregnancy and breastfeeding due to safety concerns for the fetus and infant. Despite these recommendations, nearly half of active cannabis users continue use in pregnancy. In this review, we summarize cannabis pharmacology and metabolism with a focus on delta-9-tetrahydrocannabinol, the psychoactive component of the cannabis plant, highlighting its significance in quantifying exposure and the impact on outcomes studies. We also provide a concise review of current evidence on the effects of perinatal cannabis use and pregnancy, infant, and childhood outcomes, acknowledging the limitations of this evidence. Additionally, we provide targeted counseling recommendations for harm reduction strategies and lactation considerations for birthing parents who use cannabis.

Randomized Laboratory Study of Single-Dose Cannabis, Dronabinol, and Placebo in Patients With Schizophrenia and Cannabis Use Disorder

BACKGROUND AND HYPOTHESIS

Up to 43% of people with schizophrenia have a lifetime cannabis use disorder (CUD). Tetrahydrocannabinol (THC) has been shown to exacerbate psychosis in a dose-dependent manner, but little research has assessed its effects on schizophrenia and co-occurring CUD (SCZ-CUD). In this double-dummy, placebo-controlled trial (total n = 130), we hypothesized that a modest dose of THC would worsen cognitive function but not psychosis.

STUDY DESIGN

Effects of single-dose oral THC (15 mg dronabinol) or smoked 3.5% THC cigarettes vs placebo in SCZ-CUD or CUD-only on positive and negative symptoms of schizophrenia (only for SCZ-CUD), cognition, and drug experiences assessed several hours after drug administration. SCZ-only and healthy control participants were also assessed.

STUDY RESULTS

Drug liking was higher in THC groups vs placebo. Neither smoked THC nor oral dronabinol predicted positive or negative symptom subscale scores 2 and 5 h, respectively, after drug exposure in SCZ-CUD participants. The oral dronabinol SCZ-CUD group, but not smoked THC SCZ-CUD group, performed worse than placebo on verbal learning (B = -9.89; 95% CI: -16.06, -3.18; P = .004) and attention (B = -0.61; 95% CI: -1.00, -0.23; P = .002). Every 10-point increment in serum THC + THCC ng/ml was associated with increased negative symptoms (0.40 points; 95% CI: 0.15, 0.65; P = .001; subscale ranges 7-49) and trends were observed for worse positive symptoms and performance in verbal learning, delayed recall, and working memory.

CONCLUSIONS

In people with SCZ-CUD, a modest single dose of oral THC was associated with worse cognitive functioning without symptom exacerbation several hours after administration, and a THC dose-response effect was seen for negative symptoms.

Quantification of ∆9-tetrahydrocannabinol, 11-OH-THC, THC-COOH, hexahydrocannabinol, and cannabidiol in human plasma and blood by liquid chromatography-tandem mass spectrometry

Ongoing legalization of cannabis for recreational use contributes to increasing numbers not only of incidents of driving under the influence, but within all forensic fields. In addition, newly emerging cannabinoids such as hexahydrocannabinol (HHC) and the increasing use of cannabidiol (CBD) products have to be addressed. The aims of this study were first to extend laboratory analysis capacity for the "established" cannabinoid ∆9-tetrahydrocannabinol (THC) and its metabolites 11-OH-THC and THC-COOH in human plasma/blood, and second to develop analytical procedures concerning HHC and CBD. An LC-MS-MS method based on the available (low-end) instrumentation was used. Samples (250 µl) were prepared by protein precipitation and solid-phase extraction. Chromatographic separation was achieved on a reversed-phase C18 column within 15 min. Detection was performed on a 3200 QTRAP instrument (Sciex) in positive multiple reaction monitoring (MRM) mode. Matrix-matched six-point calibrations were generated applying deuterated internal standards for all analytes except HHC. The method was fully validated according to GTFCh guidelines. Linear ranges were 0.5-25 µg/l for THC, 11-OH-THC, HHC and CBD, and 2.0-100 µg/l for THC-COOH, respectively. Limits of detection and limits of quantification were 0.5 and 1.0 µg/l (THC, 11-OH-THC, HHC, CBD), and 2.0 and 4.0 µg/l (THC-COOH). Applicability of plasma calibrations to blood samples was demonstrated. Acceptance criteria for intra- and inter-day accuracy, precision, extraction efficiency, and matrix effects were met. No interfering signals were detected for 80 exogenous compounds. The presented method is sensitive, specific, easy to handle, and does not require high-end equipment. Since its implementation and accreditation according to ISO 17025, the method has proven to be fit for purpose not only in driving under the influence of drug cases but also within postmortem samples. Furthermore, the design of the method allows for an uncomplicated extension to further cannabinoids if required.

Renal Outcomes and Other Adverse Effects of Cannabinoid Supplementation

This narrative review explores the benefits and risks of cannabinoids in kidney health, particularly in individuals with pre-existing renal conditions. It discusses the roles of cannabinoid receptor ligands (phytocannabinoids, synthetic cannabinoids, and endocannabinoids) in kidney physiology. The metabolism and excretion of these substances are also highlighted, with partial elimination occurring via the kidneys. The effects of cannabinoids on kidney function are examined, emphasizing both their potential to offer nephroprotection and the risks they may pose, such as cannabinoid hyperemesis syndrome and ischemia-reperfusion injury. These complexities underscore the intricate interactions between cannabinoids and renal health. Furthermore, this review highlights the association between chronic synthetic cannabinoid use and acute kidney injury, stressing the need for further research into their mechanisms and risks. This article also highlights the growing prevalence of edible cannabis and hemp seed consumption, emphasizing their nutritional benefits, legal regulations, and challenges such as inconsistent labeling, potential health risks, and implications for kidney health. The review delves into the roles of CB1 and CB2 receptors in diabetic nephropathy, chronic kidney disease, and obesity-related kidney dysfunction, discussing the therapeutic potential of CB2 agonists and CB1 antagonists. Additionally, it examines the potential diuretic and anti-inflammatory effects of cannabinoids in preventing kidney stones, suggesting that cannabinoids could reduce crystal retention and lower the risk of stone formation. Cannabinoids' effects on kidneys depend heavily on the characteristics of individual substances, as synthetic cannabinoids pose a major threat to the health of users. Cannabinoids offer therapeutic potential but require more research to confirm their benefits. Distinguishing between therapeutic cannabinoids and harmful synthetic variants is crucial for safe clinical application.

Considerations for Anesthesia in Older Adults with Cannabis Use

Over the past decade, legislative changes occurred in the USA and the western world that were followed by a substantial increase in reported use of cannabis among the general population. Among patients undergoing anesthesia for surgery or interventional procedures, older patients-often defined as adults over 65 years-are one of the fastest-growing populations. Within this group, the prevalence of cannabis use almost tripled over the past decade. In addition to habitual cannabis use, recommendations for treatment of chronic pain with cannabinoids have become increasingly more common. The clinical relevance of cannabis use in older adults is supported by recent studies linking it to increased anesthetic requirements as well as respiratory, cardiovascular, and psychiatric complications following surgery. Still, evidence remains equivocal, as these associations may largely depend on the type, frequency, and route of cannabis administration, and current research is mostly limited to retrospective cohort studies. Multisystemic effects of cannabis can become especially relevant in patients of advanced age undergoing anesthesia, characterized by physiological and pharmacodynamic alterations as well as a higher risks of drug-to-drug interactions. Best-practice guidelines emphasize the need for detailed, systematic preoperative screening for habits of cannabis use, including the history, type, and frequency, to guide perioperative management in these patients. This review discusses considerations for anesthesia in older patients with habitual cannabis use while highlighting strategies and recommendations to ensure safe and effective anesthesia care.

The Pharmacokinetics of Δ9-Tetrahydrocannabinol in Sheep

The pharmacokinetics of Δ9-tetrahydrocannabinol (Δ9-THC) has not been established in ruminants. Pharmacokinetic knowledge is important given feeding industrial hemp biomass has been shown to result in tissue residues post feeding in sheep. Due to a lack of testing and available data, a 'maximum' concentration of Δ9-THC has not been currently set for foods of animal origin. Consequently, this study was designed to gain a better understanding of how ruminants process Δ9-THC. Eight Merino ewes were administered with two per os (PO) doses of 88.5 mg Δ9-THC/kg bodyweight (BW) 12 h apart. Blood samples were collected periodically post dosing to determine the pharmacokinetics of Δ9-THC and subcutaneous fat biopsies were taken to investigate the deposition and elimination of Δ9-THC from sheep. An elimination half-life of 31.40 ± 13.87 h was identified, with residues persisting in the subcutaneous fat for 28 d in five of the eight sheep, before decreasing below the limit of detection in all sheep by 91 d. These results support the prolonged presence of Δ9-THC residues previously identified. Thus, imposing a practical withholding period for ruminants involved in the food chain may not be possible, with further research required to investigate how iHemp biomass may be safely fed to ruminants.

Cannabidiol Increases Psychotropic Effects and Plasma Concentrations of Δ9-Tetrahydrocannabinol Without Improving Its Analgesic Properties

Cannabidiol (CBD), the main non-intoxicating compound in cannabis, has been hypothesized to reduce the adverse effects of Δ9-tetrahydrocannabinol (THC), the main psychoactive and analgesic component of cannabis. This clinical trial investigated the hypothesis that CBD counteracts the adverse effects of THC and thereby potentially improves the tolerability of cannabis as an analgesic. A randomized, double-blind, placebo-controlled, five-way cross-over trial was performed in 37 healthy volunteers. On each visit, a double-placebo, THC 9 mg with placebo CBD, or THC 9 mg with 10, 30, or 450 mg CBD was administered orally. Psychoactive and analgesic effects were quantified using standardized test batteries. Pharmacokinetic sampling was performed. Data were analyzed using mixed-effects model. Co-administration of 450 mg CBD did not reduce, but instead significantly increased subjective, psychomotor, cognitive, and autonomous effects of THC (e.g., VAS "Feeling High" by 60.5% (95% CI: 12.7%, 128.5%, P < 0.01)), whereas THC effects with 10 and 30 mg CBD were not significantly different from THC alone. CBD did not significantly enhance THC analgesia at any dose level. Administration of 450 mg CBD significantly increased AUClast of THC (AUClast ratio: 2.18, 95% CI: 1.54, 3.08, P < 0.0001) and 11-OH-THC (AUClast ratio: 6.24, 95% CI: 4.27, 9.12, P < 0.0001) compared with THC alone, and 30 mg CBD significantly increased AUClast of 11-OH-THC (AUClast ratio: 1.89, 95% CI: 1.30, 2.77, P = 0.0013), and of THC (AUClast ratio: 1.44, 95% CI: 1.01, 2.04, P = 0.0446). Present findings do not support the use of CBD to reduce adverse effects of oral THC or enhance THC analgesia.

Sex Differences in the Neural and Behavioral Effects of Acute High-Dose Edible Cannabis Consumption in Rats

The consumption of Δ9-tetrahydrocannabinol (THC)- or cannabis-containing edibles has increased in recent years; however, the behavioral and neural circuit effects of such consumption remain unknown, especially in the context of ingestion of higher doses resulting in cannabis intoxication. We examined the neural and behavioral effects of acute high-dose edible cannabis consumption (AHDECC). Sprague-Dawley rats (six males, seven females) were implanted with electrodes in the prefrontal cortex (PFC), dorsal hippocampus (dHipp), cingulate cortex (Cg), and nucleus accumbens (NAc). Rats were provided access to a mixture of Nutella (6 g/kg) and THC-containing cannabis oil (20 mg/kg) for 10 minutes, during which they voluntarily consumed all of the provided Nutella and THC mixture. Cannabis tetrad and neural oscillations were examined 2, 4, 8, and 24 hours after exposure. In another cohort (16 males, 15 females), we examined the effects of AHDECC on learning and prepulse inhibition and serum and brain THC and 11-hydroxy-THC concentrations. AHDECC resulted in higher brain and serum THC and 11-hydroxy-THC levels in female rats over 24 hours. AHDECC also produced: 1) Cg, dHipp, and NAc gamma power suppression, with the suppression being greater in female rats, in a time-dependent manner; 2) hypolocomotion, hypothermia, and antinociception in a time-dependent manner; and 3) learning and prepulse inhibition impairments. Additionally, most neural activity and behavior changes appear 2 hours after ingestion, suggesting that interventions around this time might be effective in reversing/reducing the effects of AHDECC. SIGNIFICANCE STATEMENT: The effects of high-dose edible cannabis on behavior and neural circuitry are poorly understood. We found that the effects of acute high-dose edible cannabis consumption (AHDECC), which include decreased gamma power, hypothermia, hypolocomotion, analgesia, and learning and information processing impairments, are time and sex dependent. Moreover, these effects begin 2 hours after AHDECC and last for at least 24 hours, suggesting that treatments should target this time window in order to be effective.

Dose-dependent effect of acute THC on extinction memory recall and fear renewal: a randomized, double-blind, placebo-controlled study

RATIONALE

Prior work from our lab and others demonstrates that the endocannabinoid system is a promising avenue for improving fear memory deficits in posttraumatic stress disorder (PTSD). Specifically, 7.5 mg of delta-9-tetrahydrocannabinol (THC) decreases fear responding in healthy adults and increases prefrontal cortex activation during extinction learning and fear renewal in adults with PTSD.

OBJECTIVES

The present study will determine whether there is a dose-dependent effect of THC on short-term (24 h) and long-term (one week) fear learning and memory in adults with PTSD.

METHODS

Using a randomized, double-blind, placebo-controlled design, N = 36 adults with PTSD completed the study and were randomized to receive placebo (PBO, n = 11), 5 mg of THC (n = 11), or 10 mg of THC (n = 14) prior to fear extinction learning. Participants completed a Pavlovian conditioning paradigm with extinction recall and fear renewal occurring 24 h and one week later, where we measured concurrent functional imaging and behavioral responses.

RESULTS

Twenty-four hours after drug administration, individuals with PTSD given 5 mg of THC exhibited greater anterior cingulate cortex and prefrontal cortex activation during early fear renewal. One week later, individuals given 10 mg of THC exhibited greater hippocampus activation during extinction recall and prefrontal cortex activation during fear renewal.

CONCLUSIONS

These data suggest that dosing and timing are critical for facilitating fear memory processes in PTSD, and that low-dose oral THC prior to extinction learning can affect brain indices of fear learning and memory both acutely and one week after administration.

Sex differences in the acute effects of oral THC: a randomized, placebo-controlled, crossover human laboratory study

RATIONALE

Recent reports have shown increased cannabis use among women, leading to growing concerns about cannabis use disorder (CUD). While there is preclinical evidence suggesting biological sex influences cannabinoid effects, human research remains scant. We investigated sex differences in the acute response to oral tetrahydrocannabinol (THC) in humans.

METHODS

56 healthy men and women with prior exposure to cannabis but no history of CUD participated in a randomized, placebo-controlled, human laboratory study where they received a single 10 mg dose of oral THC (dronabinol). Subjective psychoactive effects were assessed by the visual analog scale of "high", psychotomimetic effects by the Clinician-Administered Dissociative Symptoms Scale and Psychotomimetic States Inventory, verbal learning and memory by Rey Auditory Verbal Learning Test (RAVLT), and physiological effects by heart rate. Outcomes were regularly measured on the test day, except for the RAVLT, which was assessed once. Peak differences from baseline were analyzed using a nonparametric method for repeated measures.

RESULTS

Oral THC (10 mg) demonstrated significant dose-related effects in psychotomimetic and physiological domains, but not in RAVLT outcomes. A notable interaction between THC dose and sex emerged concerning the subjective "high" scores, with women reporting heightened sensations (p = 0.05). No other significant effects of sex and THC dose interaction were observed.

CONCLUSION

Oral THC (10 mg) yields similar acute psychotomimetic and physiological effects across sexes, but women may experience a pronounced subjective psychoactive effect. Further research is needed to identify individual vulnerabilities and facilitate tailored interventions addressing CUD.

CLINICALTRIALS

GOV REGISTRATION: https://clinicaltrials.gov/study/NCT02781519?term=Ranganathan&intr=THC&rank=3 .

Making waves: Wastewater-based surveillance of cannabis use

Monitoring cannabis consumption holds great interest due to the increasing trend towards its legalization for both medicinal and recreational purposes, despite the potential risks and harms involved. Wastewater-based surveillance (WBS) offers a valuable tool for assessing shifts and patterns in drug consumption and to evaluate law enforcement strategies and harm reduction programs. However, WBS-derived cannabis use estimates have been linked to greater uncertainties compared to other drugs, in part due to the many different routes of administration and a substantial excretion of metabolites in faecal matter. Therefore, the usual approach for estimating consumed amounts and scaling consumption compared to other problem drugs requires a rethink. This viewpoint highlights the progress made in this area and describes the current existing barriers related to in-sewer and in-sample behaviour (e.g., adsorption/desorption mechanisms), analytical procedures used (e.g., sample preparation), and pharmacokinetic aspects (e.g., administration route) linked to cannabis biomarkers in influent wastewater. These need to be addressed to improve the estimation of cannabis use and reflect spatial and temporal trends in the same way as for other drugs. Until then, we recommend being cautious when interpreting wastewater-based cannabis consumption estimates.

Maternal Cannabis Use during Lactation and Potential Effects on Human Milk Composition and Production: A Narrative Review

Cannabis use has increased sharply in the last 20 y among adults, including reproductive-aged women. Its recent widespread legalization is associated with a decrease in risk perception of cannabis use during breastfeeding. However, the effect of cannabis use (if any) on milk production and milk composition is not known. This narrative review summarizes current knowledge related to maternal cannabis use during breastfeeding and provides an overview of possible pathways whereby cannabis might affect milk composition and production. Several studies have demonstrated that cannabinoids and their metabolites are detectable in human milk produced by mothers who use cannabis. Due to their physicochemical properties, cannabinoids are stored in adipose tissue, can easily reach the mammary gland, and can be secreted in milk. Moreover, cannabinoid receptors are present in adipocytes and mammary epithelial cells. The activation of these receptors directly modulates fatty acid metabolism, potentially causing changes in milk fatty acid profiles. Additionally, the endocannabinoid system is intimately connected to the endocrine system. As such, it is probable that interactions of exogenous cannabinoids with the endocannabinoid system might modify release of critical hormones (e.g., prolactin and dopamine) that regulate milk production and secretion. Nonetheless, few studies have investigated effects of cannabis use (including on milk production and composition) in lactating women. Additional research utilizing robust methodologies are needed to elucidate whether and how cannabis use affects human milk production and composition.

Sex Differences in the Acute Effects of Oral THC: A Randomized, Placebo-Controlled, Crossover Human Laboratory Study

Rationale

Recent reports have shown increased cannabis use among women, leading to growing concerns about cannabis use disorder (CUD). Some evidence suggests a faster progression to addiction in women, known as the "telescoping effect." While there is preclinical evidence suggesting biological sex influences cannabinoid effects, human research remains scant. We investigated sex differences in the response to oral tetrahydrocannabinol (THC) in humans.

Methods

56 healthy men and women with prior exposure to cannabis but no history of CUD participated in a randomized, placebo-controlled, human laboratory study where they received a single 10 mg dose of oral THC (dronabinol). Subjective psychoactive effects were assessed by the visual analog scale of "high", psychotomimetic effects by the Clinician-Administered Dissociative Symptoms Scale and Psychotomimetic States Inventory, verbal learning and memory by Rey Auditory Verbal Learning Test (RAVLT), and physiological effects by heart rate. Outcomes were regularly measured on the test day, except for the RAVLT, which was assessed once. Peak differences from baseline were analyzed using a nonparametric method for repeated measures.

Results

Oral THC demonstrated significant dose-related effects in psychotomimetic and physiological domains, but not in RAVLT outcomes. A notable interaction between THC dose and sex emerged concerning the subjective "high" scores, with women reporting heightened sensations (p=0.05). No other significant effects of sex and THC dose interaction were observed.

Conclusion

Oral THC yields similar psychotomimetic and physiological effects across sexes, but women may experience a pronounced subjective psychoactive effect. Further research is needed to identify individual vulnerabilities and facilitate tailored interventions addressing CUD.

The impact of pregnancy and associated hormones on the pharmacokinetics of Δ9-tetrahydrocannabinol

INTRODUCTION

(-)-Δ9-tetrahydrocannabinol (THC) is the main psychoactive component of cannabis. Cannabis is the most widely used drug of abuse by pregnant individuals, but its maternal-fetal safety is still unclear. The changes in THC disposition during pregnancy may affect THC safety and pharmacology.

AREAS COVERED

This review summarizes the current literature on THC metabolism and pharmacokinetics in humans. It provides an analysis of how hormonal changes during pregnancy may alter the expression of cannabinoid metabolizing enzymes and THC and its metabolite pharmacokinetics. THC is predominately (>70%) cleared by hepatic metabolism to its psychoactive active metabolite, 11-OH-THC by cytochrome P450 (CYP) 2C9 and to other metabolites (<30%) by CYP3A4. Other physiological processes that change during pregnancy and may alter cannabinoid disposition are also reviewed.

EXPERT OPINION

THC and its metabolites disposition likely change during pregnancy. Hepatic CYP2C9 and CYP3A4 are induced in pregnant individuals and in vitro by pregnancy hormones. This induction of CYP2C9 and CYP3A4 is predicted to lead to altered THC and 11-OH-THC disposition and pharmacodynamic effects. More in vitro studies of THC metabolism and induction of the enzymes metabolizing cannabinoids are necessary to improve the prediction of THC pharmacokinetics in pregnant individuals.

Sex and Gender Differences in Simultaneous Alcohol and Cannabis Use: a Narrative Review

Purpose of Review

The aim is to review recent literature on sex and gender differences in patterns of use, motives, pharmacological effects, and consequences of simultaneous alcohol and cannabis use (SAC).

Recent Findings

Men engage in SAC more frequently than women. Women may have more substance-specific motives for use, while men tend to consistently endorse social/enhancement motives for both alcohol and cannabis. Regarding pharmacological effects, women experience the same subjective effects as men do at lower levels of use, with some evidence that women modulate cannabis use during simultaneous use episodes to avoid greater subjective intoxication. Finally, women appear more vulnerable to experiencing a range of positive and negative consequences from SAC relative to men.

Summary

Research has identified several important sex/gender differences in SAC and its correlates and consequences. However, research has primarily focused on white and cisgender populations, with a need for more research among racial/ethnic and gender minorities.

Cannabidiol attenuates inflammatory impairment of intestinal cells expanding biomaterial-based therapeutic approaches

Cannabis-based biomaterials have the potential to deliver anti-inflammatory therapeutics specifically to desired cells, tissues, and organs, enhancing drug delivery and the effectiveness of anti-inflammatory treatment while minimizing toxicity. As a major component of Cannabis, Cannabidiol (CBD) has gained major attention in recent years because of its potential therapeutic properties, e.g., for restoring a disturbed barrier resulting from inflammatory conditions. The aim of this study was to test the hypothesis that CBD has beneficial effects under normal and inflammatory conditions in the established non-transformed intestinal epithelial cell model IPEC-J2. CBD induced a significant increase in transepithelial electrical resistance (TER) values and a decrease in the paracellular permeability of [³H]-D-Mannitol, indicating a strengthening effect on the barrier. Under inflammatory conditions induced by tumor necrosis factor alpha (TNFα), CBD stabilized the TER and mitigated the increase in paracellular permeability. Additionally, CBD prevented the barrier-disrupting effects of TNFα on the distribution and localization of sealing TJ proteins. CBD also affected the expression of TNF receptors. These findings demonstrate the potential of CBD as a component of Cannabis-based biomaterials used in the development of novel therapeutic approaches against inflammatory pathogenesis.

Sex Differences in Plasma, Adipose Tissue, and Central Accumulation of Cannabinoids, and Behavioral Effects of Oral Cannabis Consumption in Male and Female C57BL/6 Mice

BACKGROUND

Cannabis edibles are an increasingly popular form of cannabis consumption. Oral consumption of cannabis has distinct physiological and behavioral effects compared with injection or inhalation. An animal model is needed to understand the pharmacokinetics and physiological effects of oral cannabis consumption in rodents as a model for human cannabis edible use.

METHODS

Adult male and female C57BL/6 mice received a single dose of commercially available cannabis oil (5 mg/kg Δ⁹-tetrahydrocannabinol [THC]) by oral gavage. At 0.5, 1, 2, 3, and 6 hours post exposure, plasma, hippocampus, and adipose tissue were collected for THC, 11-OH-THC, and THC-COOH measures.

RESULTS

We report delayed time to peak THC and 11-OH-THC concentrations in plasma, brain, and adipose tissue, which is consistent with human pharmacokinetics studies. We also found sex differences in the cannabis tetrad: (1) female mice had a delayed hypothermic effect 6 hours post consumption, which was not present in males; (2) females had stronger catalepsy than males; (3) males were less mobile following cannabis exposure, whereas female mice showed no difference in locomotion but an anxiogenic effect at 3 hours post exposure; and (4) male mice displayed a longer-lasting antinociceptive effect of oral cannabis.

CONCLUSIONS

Oral cannabis consumption is a translationally relevant form of administration that produces similar physiological effects as injection or vaping administration and thus should be considered as a viable approach for examining the physiological effects of cannabis moving forward. Furthermore, given the strong sex differences in metabolism of oral cannabis, these factors should be carefully considered when designing animal studies on the effects of cannabis.

Confirmation of cannabinoids in forensic toxicology casework by isomer-selective UPLC-MS-MS analysis in urine

Confirmation of cannabinoid use by forensic toxicology testing in urine has been traditionally focused on ∆9-tetrahydrocannabinol (∆9-THC) with analysis of its major metabolite, 11-nor-9-carboxy-∆9-THC (∆9-cTHC), in free and conjugated forms. Legalization of hemp, however, has led to the widespread production and sale of cannabidiol (CBD) derivatives with psycho-activity, including ∆8-THC and ∆10-THC isomers. The increasing availability and growing use of isomer derivatives necessitate an expanded scope of cannabinoid confirmation test protocols. We report a quantitative, isomer-selective method of cannabinoid confirmation by liquid chromatography-tandem mass spectrometry determination of parent drug isomers (∆8-THC, ∆9-THC, ∆10-THC and CBD) as well as isomeric metabolites (∆8-cTHC and ∆9-cTHC). An efficient C18 phase chromatography on 1.6-µm solid core particles was used with a step gradient for near isocratic separation of both early-eluting THC metabolite isomers and later-eluting CBD and THC isomers. A rapid method of hydrolysis, dilution and analysis was employed for the quantitative co-determination of free and conjugated analytes, using stable isotope internal standardization. Method validation is reported, along with interference assessment from a prior confirmation method. Casework experience with the isomer-selective method revealed a 14% prevalence of ∆8-cTHC positive cases with a pattern of concomitant ∆8-THC and ∆9-THC use. A comparison of ∆8-cTHC and ∆9-cTHC phase two metabolism is also reported.

Predicting Maternal and Infant Tetrahydrocannabinol Exposure in Lactating Cannabis Users: A Physiologically Based Pharmacokinetic Modeling Approach

A knowledge gap exists in infant tetrahydrocannabinol (THC) data to guide breastfeeding recommendations for mothers who use cannabis. In the present study, a paired lactation and infant physiologically based pharmacokinetic (PBPK) model was developed and verified. The verified model was used to simulate one hundred virtual lactating mothers (mean age: 28 years, body weight: 78 kg) who smoked 0.32 g of cannabis containing 14.14% THC, either once or multiple times. The simulated breastfeeding conditions included one-hour post smoking and subsequently every three hours. The mean peak concentration (Cmax) and area under the concentration-time curve (AUC(0-24 h)) for breastmilk were higher than in plasma (Cmax: 155 vs. 69.9 ng/mL; AUC(0-24 h): 924.9 vs. 273.4 ng·hr/mL) with a milk-to-plasma AUC ratio of 3.3. The predicted relative infant dose ranged from 0.34% to 0.88% for infants consuming THC-containing breastmilk between birth and 12 months. However, the mother-to-infant plasma AUC(0-24 h) ratio increased up to three-fold (3.4-3.6) with increased maternal cannabis smoking up to six times. Our study demonstrated the successful development and application of a lactation and infant PBPK model for exploring THC exposure in infants, and the results can potentially inform breastfeeding recommendations.

Variable Delta-9-Tetrahydrocannabinol Pharmacokinetics and Pharmacodynamics After Cannabis Smoking in Regular Users

BACKGROUND

Despite its federally restricted status, cannabis is widely used medicinally and recreationally. The pharmacokinetics (PK) and central nervous system (CNS) effects of tetrahydrocannabinol (THC), the major psychoactive cannabinoid, are not well understood. The objective of this study was to develop a population PK model of inhaled THC, including sources of variability, and to conduct an exploratory analysis of potential exposure-response relationships.

METHODS

Regular adult cannabis users smoked a single cannabis cigarette containing 5.9% THC (Chemovar A) or 13.4% THC (Chemovar B) ad libitum. THC concentrations in whole blood were measured and used to develop a population PK model to identify potential factors contributing to interindividual variability in THC PK and to describe THC disposition. Relationships between model-predicted exposure and heart rate, change in composite driving score on a driving simulator, and perceived highness were evaluated.

RESULTS

From the 102 participants, a total of 770 blood THC concentrations were obtained. A two-compartment structural model adequately fit the data. Chemovar and baseline THC (THC BL ) were found to be significant covariates for bioavailability, with Chemovar A having better THC absorption. The model predicted that heavy users-those with the highest THC BL -would have significantly higher absorption than those with lighter previous use. There was a statistically significant relationship between exposure and heart rate, and exposure and perceived highness.

CONCLUSIONS

THC PK is highly variable and related to baseline THC concentrations and different chemovars. The developed population PK model showed that heavier users had higher THC bioavailability. To better understand the factors affecting THC PK and dose-response relationships, future studies should incorporate a wide range of doses, multiple routes of administration, and different formulations relevant to typical community use.

Development of a quick preparation method for the analysis of 11-nor-9-carboxy-∆9-tetrahydrocannabinol in human urine by phenylboronic-acid solid-phase extraction

A rapid preparation method for the analysis of the urine from a cannabis user was established. Generally, 11-nor-9-carboxy-∆9-tetrahydrocannabinol (THC-COOH), which is one of the main metabolites of ∆9-tetrahydorocannabinol (THC), must be detected from a user's urine to verify cannabis use. However, existing preparation methods are usually multistep and time-consuming processes. Before the analysis by liquid-chromatography tandem mass spectrometry (LC-MS/MS), deconjugation by treatment with β-glucuronidase or alkaline solution, liquid-liquid extraction or solid-phase extraction (SPE), and evaporation are generally performed. In addition, subsequent derivatization (silylation or methylation) are certainly necessary for gas-chromatography mass spectrometry (GC/MS) analysis. Here, we focused on the phenylboronic-acid (PBA) SPE, which selectively binds compounds with a cis-diol moiety. THC-COOH is metabolized as a glucuronide conjugate (THC-COOGlu) which has cis-diol moieties, therefore, we investigated the conditions of its retention and elution to reduce the operating time. We developed four elution conditions, which afford the following derivatives: acidic elution for THC-COOGlu, alkaline elution for THC-COOH, methanolysis elution for the THC-COOH methyl ester (THC-COOMe), and methanolysis elution and following methyl etherification for O-methyl-THC-COOMe (O-Me-THC-COOMe). All repeatability and recovery rates were evaluated by LC-MS/MS in this study. As a result, these four pathways required short times (within 10-25 min) and exhibited good repeatability and recovery rates. Detection limits of pathway I-IV were 10.8, 1.7, 18.9, and 13.8 ng mL-1, respectively. Lower limits of quantification were 62.5, 31.25, 57.3, and 62.5 ng mL-1, respectively. When proof of cannabis use is required, any elution condition can be selected to match the possessing reference standards and analytical instruments. To our knowledge, this is the first report of using PBA SPE for the preparation of the urine samples containing cannabis and achieving partial derivatization when eluting from a PBA carrier. Our method can provide a new and practical solution for the preparation of the urine samples from cannabis users. Although the PBA SPE method cannot recover THC-COOH in urine because of its lack of a 1,2-diol moiety, this method has technological advantages for simplifying the process and reducing the operating time, thereby avoiding human errors.

LC-MS-MS-MS3 for the determination and quantification of ∆9-tetrahydrocannabinol and metabolites in blood samples

Due to the high prevalence of cannabinoids in forensic toxicology analysis, it is crucial to have an efficient method that allows the use of a small sample amount and that requires a minimal sample preparation for the determination and quantification of low concentrations. A simple, highly selective and high throughput liquid chromatography-tandem mass spectrometry methodology (LC-MS-MS-MS3) was developed for the determination and quantification of ∆9-tetrahydrocannabinol (THC), 11-hydroxy-∆9- tetrahydrocannabinol (THC-OH) and 11-nor-9-carboxy-∆9-tetrahydrocannabinol (THC-COOH) in blood samples. Chromatographic analysis of THC, THC-OH and THC-COOH and their deuterated internal standards was preceded by protein precipitation (PPT) of 0.1 mL of blood samples with acetonitrile. Chromatographic separation was achieved by use of an Acquity UPLC® HHS T3 (100 mm × 2.1 mm i.d., 1.8 μm) reversed-phase column, using a gradient elution of 2 mM aqueous ammonium formate, 0.1% formic acid and methanol at a flow rate of 0.4 mL/min, with a run time of 10 min. For the MS-MS-MS3 analysis, a SCIEX QTRAP® 6500+ triple quadrupole linear ion trap mass spectrometer was used via electrospray ionization (ESI), operated in multiple reaction monitoring (MRM) and linear ion trap mode (MS3). The method was validated in accordance with internationally accepted criteria and guidelines, and proved to be selective and linear between 0.5 and 100 ng/mL (r2 > 0.995). The lower limits of quantification (LLOQ) corresponded to the lowest concentrations used for the calibration curves. The coefficients of variation obtained for accuracy and precision were <15%. The mean recoveries were between 88.0% and 117.2% for the studied concentration levels (1 ng/mL, 5 ng/mL and 50 ng/mL). No significant interfering compounds, matrix effects or carryover were observed. The validated method provides a sensitive, efficient and robust procedure for the quantification of cannabinoids in blood, using LC-MS-MS-MS3 and a sample volume of 0.1 mL. This work is also a proof of concept for using LC-MS3 technique to determine drugs in biological samples.

Toxic Tetrahydrocannabinol (THC) Dose in Pediatric Cannabis Edible Ingestions

OBJECTIVE

The study characterizes cannabis toxicity in relation to tetrahydrocannabinol (THC) dose in pediatric edible cannabis ingestions.

METHODS

This is a retrospective review of children aged <6 years presenting with edible cannabis ingestions of known THC dose within a pediatric hospital network (January 1, 2015-October 25, 2022). Cannabis toxicity was characterized as severe if patients exhibited severe cardiovascular (bradycardia, tachycardia/hypotension requiring vasopressors or intravenous fluids, other dysrhythmias), respiratory (respiratory failure, apnea, requiring oxygen supplementation), or neurologic (seizure, myoclonus, unresponsiveness, responsiveness to painful stimulation only, requiring intubation or sedation) effects. Cannabis toxicity was characterized as prolonged if patients required >6 hours to reach baseline. The relationship between THC dose and severe and prolonged toxicity was explored using multivariable logistic regression and receiver operator characteristic curve analyses.

RESULTS

Eighty patients met inclusion. The median age was 2.9 years. The median THC ingestion was 2.1 mg/kg. Severe and prolonged toxicity was present in 46% and 74%, respectively. THC dose was a significant predictor of severe (adjusted odds ratio 2.9, 95% confidence interval: 1.8-4.7) and prolonged toxicity (adjusted odds ratio 3.2, 95% confidence interval: 1.6-6.5), whereas age and sex were not. Area under the curve was 92.9% for severe and 87.3% for prolonged toxicity. THC ingestions of ≥1.7 mg/kg can predict severe (sensitivity 97.3%) and prolonged toxicity (sensitivity 75.4%).

CONCLUSIONS

The THC dose of edible cannabis correlates to the degree of toxicity in children <6 years old. The threshold of 1.7 mg/kg of THC may guide medical management and preventive regulations.

Decoding the Postulated Entourage Effect of Medicinal Cannabis: What It Is and What It Isn't

The 'entourage effect' term was originally coined in a pre-clinical study observing endogenous bio-inactive metabolites potentiating the activity of a bioactive endocannabinoid. As a hypothetical afterthought, this was proposed to hold general relevance to the usage of products based on Cannabis sativa L. The term was later juxtaposed to polypharmacy pertaining to full-spectrum medicinal Cannabis products exerting an overall higher effect than the single compounds. Since the emergence of the term, a discussion of its pharmacological foundation and relevance has been ongoing. Advocates suggest that the 'entourage effect' is the reason many patients experience an overall better effect from full-spectrum products. Critics state that the term is unfounded and used primarily for marketing purposes in the Cannabis industry. This scoping review aims to segregate the primary research claiming as well as disputing the existence of the 'entourage effect' from a pharmacological perspective. The literature on this topic is in its infancy. Existing pre-clinical and clinical studies are in general based on simplistic methodologies and show contradictory findings, with the clinical data mostly relying on anecdotal and real-world evidence. We propose that the 'entourage effect' is explained by traditional pharmacological terms pertaining to other plant-based medicinal products and polypharmacy in general (e.g., synergistic interactions and bioenhancement).

Cannabis and Pregnancy: A Review

Importance

Prenatal cannabis use is rising and is a major public health issue. Cannabis use in pregnancy and during lactation has been associated with increased maternal and offspring morbidity and mortality.

Objective

This review aims to summarize the existing literature and current recommendations for cannabis use during pregnancy or lactation.

Evidence Acquisition

A PubMed, Cochrane Library, and Google Scholar literature search using the following terms was performed to gather relevant data: "cannabis," "cannabinoid," "delta-9-tetrahydrocannabinol," "THC," "cannabidiol," "fetal outcomes," "perinatal outcomes," "pregnancy," and "lactation."

Results

Available studies on cannabis use in pregnancy and during lactation were reviewed and support an association with increased risk of preterm birth, neonatal intensive care unit admission, low birth weight, and small-for-gestational-age infants.

Conclusion and Relevance

There is a critical need for research on the effects of cannabis use in pregnancy and during lactation. This is a necessary first step before furthering patient education, developing interventions, and targeting antenatal surveillance to ameliorate the adverse impacts on maternal and fetal health.

Establishment of a point of departure for CBD hepatotoxicity employing human HepaRG spheroids

The United States Food and Drug Administration recently approved the use of Cannabis sativa derived cannabidiol (CBD) in the treatment of Dravet Syndrome and Lennox-Gastaut Syndrome, under the trade name, Epidiolex. In double-blinded, placebo-controlled clinical trials, elevated ALT levels were observed in some patients, but these findings could not be uncoupled from the confounds of potential drug-drug interactions with co-administration of valproate and clobazam. Given the uncertainty of the potential hepatatoxic effects of CBD, the objective of the present study was to determine a point of departure for CBD, using human HepaRG spheroid cultures, followed by transcriptomic benchmark dose analysis. Treatment of HepaRG spheroids with CBD for 24 and 72 h, resulted in EC50 concentrations for cytotoxicity of 86.27 µM and 58.04 µM, respectively. Subsequent transcriptomic analysis at these timepoints demonstrated little alteration of gene and pathway data sets at a CBD concentration at or below 10 µM. Although this current analysis was conducted using liver cells, interestingly the findings at 72 h post CBD treatment showed suppression of many genes more commonly associated with immune regulation. Indeed, the immune system is a well-established target for CBD based on immune function assays. Collectively, in the present studies a point of departure was derived using transcriptomic changes produced by CBD in a human cell-based model system, which has been shown to accurately translate to human hepatotoxicity modeling.

ASRA Pain Medicine consensus guidelines on the management of the perioperative patient on cannabis and cannabinoids

BACKGROUND

The past two decades have seen an increase in cannabis use due to both regulatory changes and an interest in potential therapeutic effects of the substance, yet many aspects of the substance and their health implications remain controversial or unclear.

METHODS

In November 2020, the American Society of Regional Anesthesia and Pain Medicine charged the Cannabis Working Group to develop guidelines for the perioperative use of cannabis. The Perioperative Use of Cannabis and Cannabinoids Guidelines Committee was charged with drafting responses to the nine key questions using a modified Delphi method with the overall goal of producing a document focused on the safe management of surgical patients using cannabinoids. A consensus recommendation required ≥75% agreement.

RESULTS

Nine questions were selected, with 100% consensus achieved on third-round voting. Topics addressed included perioperative screening, postponement of elective surgery, concomitant use of opioid and cannabis perioperatively, implications for parturients, adjustment in anesthetic and analgesics intraoperatively, postoperative monitoring, cannabis use disorder, and postoperative concerns. Surgical patients using cannabinoids are at potential increased risk for negative perioperative outcomes.

CONCLUSIONS

Specific clinical recommendations for perioperative management of cannabis and cannabinoids were successfully created.

Cannabinoids and the endocannabinoid system in fibromyalgia: A review of preclinical and clinical research

Characterised by chronic widespread musculoskeletal pain, generalised hyperalgesia, and psychological distress, fibromyalgia (FM) is a significant unmet clinical need. The endogenous cannabinoid system plays an important role in modulating both pain and the stress response. Here, we appraise the evidence, from preclinical and clinical studies, for a role of the endocannabinoid system in FM and the therapeutic potential of targeting the endocannabinoid system. While many animal models have been used to study FM, the reserpine-induced myalgia model has emerged as perhaps the most translatable to the clinical phenotype. Inhibition of fatty acid amide hydrolase (FAAH) has shown promise in preclinical studies, ameliorating pain- and anxiety-related behaviour . Clinically, there is evidence for alterations in the endocannabinoid system in patients with FM, including single nucleotide polymorphisms and increased levels of circulating endocannabinoids and related N-acylethanolamines. Single entity cannabinoids, cannabis, and cannabis-based medicines in patients with FM show promise therapeutically but limitations in methodology and lack of longitudinal studies to assess efficacy and tolerability preclude the current recommendation for their use in patients with FM. Gaps in the literature that warrant further investigation are discussed, particularly the need for further development of animal models with high validity for the multifaceted nature of FM, balanced studies to eliminate sex-bias in preclinical research, and ultimately, better translation between preclinical and clinical research.

Review of delta-8-tetrahydrocannabinol (Δ8 -THC): Comparative pharmacology with Δ9 -THC

The use of the intoxicating cannabinoid delta-8-tetrahydrocannabinol (Δ⁸ -THC) has grown rapidly over the last several years. There have been dozens of Δ⁸ -THC studies dating back over many decades, yet no review articles have comprehensively covered these findings. In this review, we summarize the pharmacological studies of Δ⁸ -THC, including receptor binding, cell signalling, in vivo cannabimimetic activity, clinical activity and pharmacokinetics. We give special focus to studies that directly compared Δ⁸ -THC to its more commonly studied isomer, Δ⁹ -THC. Overall, the pharmacokinetics and pharmacodynamics of Δ⁸ -THC and Δ⁹ -THC are very similar. Δ⁸ -THC is a partial agonist of the cannabinoid CB₁ receptor and has cannabimimetic activity in both animals and humans. The reduced potency of Δ⁸ -THC in clinical studies compared with Δ⁹ -THC can be explained by weaker cannabinoid CB₁ receptor affinity, although there are other plausible mechanisms that may contribute. We highlight the gaps in our knowledge of Δ⁸ -THC pharmacology where further studies are needed, particularly in humans.

Impact of cannabinoids on pregnancy, reproductive health and offspring outcomes

Cannabis is the most commonly used federally illegal drug in the United States and world, especially among people of reproductive age. In addition, the potency of cannabis products has increased significantly in the past decade. This is concerning because the available evidence suggests an adverse effect from cannabis exposure on male and female reproductive health. Exposure to cannabinoids may have differential impacts on female reproductive health across a woman's lifespan, from preconception to pregnancy, throughout lactation, and during menopause. Even more, cannabis use has been associated an adverse effect on fetal outcomes, and longer-term offspring health and developmental trajectories. Despite the prevalence of cannabis use, there is limited available evidence regarding its safety, especially in regard to reproductive health, pregnancy and lactation. The biological effects of cannabis are mediated by the endocannabinoid system and studies have reported the presence of cannabinoid receptors in the male and female reproductive tract, on sperm and the placenta, suggesting the endocannabinoid system plays a role in regulating reproduction. Cannabis use can impact male and female fertility and has been associated with altered reproductive hormones, menstrual cyclicity and semen parameters. Use of cannabis in males has also been associated with erectile dysfunction, abnormal spermatogenesis, and testicular atrophy. In females, cannabis use has been associated with infertility and abnormal embryo implantation and development. The main psychoactive component of cannabis, delta-9-tetrahydrocannabinol (THC), can also cross the placenta and has been detected in breastmilk. Maternal cannabis use during pregnancy and lactation has been associated with adverse effects including small for gestational age infants, preterm birth, fetal neurodevelopmental consequences, and impaired offspring sociobehavioral and cognitive development. The prevalence of cannabis use to alleviate menopausal symptoms has also increased despite the limited information on its benefits and safety. As cannabis use is on the rise, it is critical to understand its impact on reproductive health and offspring developmental outcomes. This is an understudied, but timely subject, with much needed information to guide healthcare providers and those interested in conceiving, or that are pregnant and lactating, as well as those at the end of their reproductive time span.

Sex differences in the acute effects of intravenous (IV) delta-9 tetrahydrocannabinol (THC)

BACKGROUND

Cannabis is the most common illicit drug used in the USA and its use has been rising over the past decade, while the historical gap in rates of use between men and women has been decreasing. Sex differences in the effects of cannabinoids have been reported in animal models, but human studies are sparse and inconsistent. We investigated the sex differences in the acute subjective, psychotomimetic, cognitive, and physiological effects of intravenous (IV) delta-9 tetrahydrocannabinol (THC), the main psychoactive constituent of cannabis.

METHODS

Healthy male and female individuals, with limited exposure to cannabis, participated in a double blind, placebo-controlled study of intravenous (IV) placebo or THC at two doses (0.015 mg/kg and 0.03 mg/kg). Visual analog scale (VAS) was used to measure subjective effects, Psychotomimetic States Inventory (PSI) and the Clinician-Administered Dissociative Symptoms Scale (CADSS) were used to assess the psychotomimetic effects and perceptual alterations, respectively, and Rey Auditory Verbal Learning Task (RAVLT) was used to evaluate cognitive effects. Outcome variables were represented as the peak change from baseline for each variable, except RAVLT which was used only once per the test day after the subjective effects.

RESULTS

A total of 42 individuals participated in this study. There were no significant differences between male and female participants in background characteristics. There was a significant main effect of sex on the VAS scores for THC-induced "High" (F1,38 = 4.27, p < 0.05) and a significant dose × sex interaction (F2,77 = 3.38, p < 0.05) with female participants having greater "High" scores than male participants at the lower THC dose (0.015 mg/kg). No other sex differences were observed in acute subjective, psychotomimetic, cognitive, or physiological effects of THC.

CONCLUSION

There were significant sex differences in subjective effects of feeling "High" at a lower dose of THC. However, there were no other sex-related differences in the subjective, physiological, or cognitive effects of THC.

Cannabinoid tetrad effects of oral Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD) in male and female rats: sex, dose-effects and time course evaluations

RATIONALE

The legalization of medicinal use of Cannabis sativa in most US states and the removal of hemp from the Drug Enforcement Agency (DEA) controlled substances act has resulted in a proliferation of products containing Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD) for oral consumption (e.g., edibles, oils, and tinctures) that are being used for recreational and medicinal purposes.

OBJECTIVE

This study examined the effects of cannabinoids THC and CBD when administered orally on measures of pain sensitivity, body temperature, locomotor activity, and catalepsy (i.e., cannabinoid tetrad) in male and female Sprague Dawley rats.

METHODS

Rats (N = 24, 6 per sex/drug group) were administered THC (1-20 mg/kg), CBD (3-30 mg/kg), or sesame oil via oral gavage. Thermal and mechanical pain sensitivity (tail flick assay, von Frey test), rectal measurements for body temperature, locomotor activity, and the bar-test of catalepsy were completed. A separate group of rats (N = 8/4 per sex) was administered morphine (5-20 mg/kg; intraperitoneal, IP) and evaluated for pain sensitivity as a positive control.

RESULTS

We observed classic tetrad effects of antinociception, hypothermia, hyper- and hypolocomotion, and catalepsy after oral administration of THC that were long lasting (> 7 h). CBD modestly increased mechanical pain sensitivity and produced sex-dependent effects on body temperature and locomotor activity.

CONCLUSIONS

Oral THC and CBD produced long lasting effects that differed in magnitude and time course when compared with other routes of administration. Examination of cannabinoid effects administered via different routes of administration, species, and in both males and females is critical to enhance translation.

Translational models of cannabinoid vapor exposure in laboratory animals

Cannabis is one of the most frequently used psychoactive substances in the world. The most common route of administration for cannabis and cannabinoid constituents such as Δ-9-tetrahydrocannabinol (THC) and cannabidiol (CBD) is via smoking or vapor inhalation. Preclinical vapor models have been developed, although the vaporization devices and delivery methods vary widely across laboratories. This review examines the emerging field of preclinical vapor models with a focus on cannabinoid exposure in order to (1) summarize vapor exposure parameters and other methodological details across studies; (2) discuss the pharmacological and behavioral effects produced by exposure to vaporized cannabinoids; and (3) compare behavioral effects of cannabinoid vapor administration with those of other routes of administration. This review will serve as a guide for past and current vapor delivery methods in animals, synergize findings across studies, and propose future directions for this area of research.

A critical review of cannabis in medicine and dentistry: A look back and the path forward

Introduction

In the last two decades, our understanding of the therapeutic utility and medicinal properties of cannabis has greatly changed. This change has been accompanied by widespread cannabis use in various communities and different age groups, especially within the United States. With this increase, we should consider the potential effects of cannabis–hemp on general public health and how they could alter therapeutic outcomes.

Material and Methods

The present investigation examined cannabis use for recreational and therapeutic use and a review of pertinent indexed literature was performed. The focused question evaluates “how cannabis or hemp products impact health parameters and do they provide potential therapeutic value in dentistry, and how do they interact with conventional medicines (drugs).” Indexed databases (PubMed/Medline, EMBASE) were searched without any time restrictions but language was restricted to English.

Results

The review highlights dental concerns of cannabis usage, the need to understand the endocannabinoid system (ECS), cannabinoid receptor system, its endogenous ligands, pharmacology, metabolism, current oral health, and medical dilemma to ascertain the detrimental or beneficial effects of using cannabis–hemp products. The pharmacological effects of pure cannabidiol (CBD) have been studied extensively while cannabis extracts can vary significantly and lack empirical studies. Several metabolic pathways are affected by cannabis use and could pose a potential drug interaction. The chronic use of cannabis is associated with health issues, but the therapeutic potential is multifold since there is a regulatory role of ECS in many pathologies.

Conclusion

Current shortcomings in understanding the benefits of cannabis or hemp products are limited due to pharmacological and clinical effects not being predictable, while marketed products vary greatly in phytocompounds warrant further empirical investigation. Given the healthcare challenges to manage acute and chronic pain, this review highlights both cannabis and CBD‐hemp extracts to help identify the therapeutic application for patient populations suffering from anxiety, inflammation, and dental pain.

Automation System for the Flexible Sample Preparation for Quantification of Δ9-THC-D3, THC-OH and THC-COOH from Serum, Saliva and Urine

In the life sciences, automation solutions are primarily established in the field of drug discovery. However, there is also an increasing need for automated solutions in the field of medical diagnostics, e.g., for the determination of vitamins, medication or drug abuse. While the actual metrological determination is highly automated today, the necessary sample preparation processes are still mainly carried out manually. In the laboratory, flexible solutions are required that can be used to determine different target substances in different matrices. A suitable system based on an automated liquid handler was implemented. It has been tested and validated for the determination of three cannabinoid metabolites in blood, urine and saliva. To extract Δ9-tetrahydrocannabinol-D3 (Δ9-THC-D3), 11-hydroxy-Δ9-tetrahydrocannabinol (THC-OH) and 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (THC-COOH) from serum, urine and saliva both rapidly and cost-effectively, three sample preparation methods automated with a liquid handling robot are presented in this article, the basic framework of which is an identical SPE method so that they can be quickly exchanged against each other when the matrix is changed. If necessary, the three matrices could also be prepared in parallel. For the sensitive detection of analytes, protein precipitation is used when preparing serum before SPE and basic hydrolysis is used for urine to cleave the glucuronide conjugate. Recoveries of developed methods are >77%. Coefficients of variation are <4%. LODs are below 1 ng/mL and a comparison with the manual process shows a significant cost reduction.

The Transdermal Delivery of Therapeutic Cannabinoids

Recently, several studies have indicated an increased interest in the scientific community regarding the application of Cannabis sativa plants, and their extracts, for medicinal purposes. This plant of enormous medicinal potential has been legalised in an increasing number of countries globally. Due to the recent changes in therapeutic and recreational legislation, cannabis and cannabinoids are now frequently permitted for use in clinical settings. However, with their highly lipophilic features and very low aqueous solubility, cannabinoids are prone to degradation, specifically in solution, as they are light-, temperature-, and auto-oxidation-sensitive. Thus, plant-derived cannabinoids have been developed for oral, nasal-inhalation, intranasal, mucosal (sublingual and buccal), transcutaneous (transdermal), local (topical), and parenteral deliveries. Among these administrations routes, topical and transdermal products usually have a higher bioavailability rate with a prolonged steady-state plasma concentration. Additionally, these administrations have the potential to eliminate the psychotropic impacts of the drug by its diffusion into a nonreactive, dead stratum corneum. This modality avoids oral administration and, thus, the first-pass metabolism, leading to constant cannabinoid plasma levels. This review article investigates the practicality of delivering therapeutic cannabinoids via skin in accordance with existing literature.

An Approach to Biomarker Discovery of Cannabis Use Utilizing Proteomic, Metabolomic, and Lipidomic Analyses

Introduction: Relatively little is known about the molecular pathways influenced by cannabis use in humans. We used a multi-omics approach to examine protein, metabolomic, and lipid markers in plasma differentiating between cannabis users and nonusers to understand markers associated with cannabis use. Methods: Eight discordant twin pairs and four concordant twin pairs for cannabis use completed a blood draw, urine and plasma toxicology testing, and provided information about their past 30-day cannabis use and other substance use patterns. The 24 twins were all non-Hispanic whites. Sixty-six percent were female. Median age was 30 years. Fifteen participants reported that they had used cannabis in the last 30 days, including eight participants that used every day or almost every day (29-30 of 30 days). Of these 15 participants, plasma 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (THC-COOH) and total tetrahydrocannabinol (THC) concentrations were detectable in 12 participants. Among the eight "heavy users" the amount of total THC (sum of THC and its metabolites) and plasma THC-COOH concentrations varied widely, with ranges of 13.1-1713 ng/mL and 2.7-284 ng/mL, respectively. A validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay measured plasma THC-COOH, THC, and other cannabinoids and metabolites. Plasma THC-COOH was used as the primary measure. Expression levels of 1305 proteins were measured using SOMAScan assay, and 34 lipid mediators and 314 metabolites were measured with LC-MS/MS. Analyses examined associations between markers and THC-COOH levels with and without taking genetic relatedness into account. Results: Thirteen proteins, three metabolites, and two lipids were identified as associated with THC-COOH levels. Myc proto-oncogene was identified as associated with THC-COOH levels in both molecular insight and potential marker analyses. Five pathways (interleukin-6 production, T lymphocyte regulation, apoptosis, kinase signaling pathways, and nuclear factor kappa-light-chain-enhancer of activated B cells) were linked with molecules identified in these analyses. Conclusions: THC-COOH levels are associated with immune system-related pathways. This study presents a feasible approach to identify additional molecular markers associated with THC-COOH levels.

Partitioning of phytocannabinoids between faeces and water - Implications for wastewater-based epidemiology

Evaluating consumption estimates for lipophilic drugs in wastewater has proven to be a challenge. A common feature for these compounds is that they are excreted in faeces and in conjugated form in urine. Limited research with no obvious experimental evidence has been conducted to investigate the degree to which faecal-bound chemical markers contribute towards mass loads in wastewater. Cannabis chemical markers, known as phytocannabinoids, have been suggested in literature to fall into this category. In this study, cannabis users (n = 9) and non-cannabis users (n = 5) were recruited and provided faecal and urine samples after using the substance. The common chemical markers of cannabis consumption, 11-nor-9-carboxy-Δ⁹-tetrahydrocannabinol (THC-COOH), 11-hydroxy-Δ⁹-tetrahydrocannabinol (THC-OH), Δ⁹-tetrahydrocannabinol (THC) and cannabidiol (CBD), were investigated. An extraction method was developed for the cannabis chemical markers in faecal matter and urine and analysis was performed by liquid chromatography-mass spectrometry. Participant samples were used to establish adsorption and desorption dissolution kinetics models and to assess the equilibrium between faeces and water for these compounds. Equilibration between phases were found to be fast (<5 min). THC-COOH, which is the primary metabolite used in wastewater studies, partitioned ~40% in water while the less polar metabolite and CBD remained largely associated with the particulate fraction. Faecal loads of both cannabis users and non-users affected the total measured amounts of cannabinoids in the aqueous phase. The implications for wastewater monitoring of lipophilic substances are discussed.

A Phase I Trial to Determine the Pharmacokinetics, Psychotropic Effects, and Safety Profile of a Novel Nanoparticle-Based Cannabinoid Spray for Oromucosal Delivery

INTRODUCTION

A phase I, open-label clinical trial in healthy male subjects was conducted to assess the pharmacokinetic and safety profile of an oromucosal cannabinoid spray (AP701) containing a lipid-based nanoparticular drug formulation standardized to ∆-9-tetrahydrocannabinol (THC).

METHODS

Twelve healthy male subjects received a single dose of AP701 (12 sprays) containing 3.96 mg THC. Plasma samples were drawn 10 min-30 h post dose for analysis of THC and the active metabolite 11-hydroxy-∆-9-THC (11-OH-THC).

RESULTS

The single dose of the applied oromucosal cannabinoid spray AP701 (12 sprays, 3.96 mg THC) resulted in a mean maximum plasma concentration (Cmax) of 2.23 ng/mL (90% CI 1.22-3.24) and a mean overall exposure (area under the concentration-time curve from time 0 to last measurable concentration [AUC0-t]) of 7.74 h × ng/mL (90% CI 5.03-10.45) for THC. For the active metabolite 11-OH-THC, a Cmax of 2.09 mg/mL (90% CI 1.50-2.68) and AUC0-t of 10.4 h × ng/mL (90% CI 7.03-13.77) was found. The oromucosal cannabinoid spray AP701 caused only minor psychotropic effects despite the relatively high dosage applied by healthy subjects. No serious adverse effects occurred. Overall, the oromucosal cannabinoid spray AP701 was well tolerated.

CONCLUSION

Compared to currently available drugs on the market, higher AUC values could be detected for the oromucosal cannabinoid spray AP701 despite administration of a lower dose. These comparatively higher blood levels caused only minor psychotropic adverse effects. The oromucosal cannabinoid spray AP701 was well tolerated at a single dose of 3.96 mg THC. The oromucosal administration may provide an easily applicable and titratable drug formulation with a high safety and tolerability profile.

Clinical Approaches to Cannabis: A Narrative Review

Cannabis use in the United States is growing at an unprecedented pace. Most states in the United States have legalized medical cannabis use, and many have legalized nonmedical cannabis use. In this setting, health care professionals will increasingly see more patients who have questions about cannabis use, its utility for medical conditions, and the risks of its use. This narrative review provides an overview of the background, pharmacology, therapeutic use, and potential complications of cannabis.

Cannabinoid Metabolites as Inhibitors of Major Hepatic CYP450 Enzymes, with Implications for Cannabis-Drug Interactions

The legalization of cannabis in many parts of the United States and other countries has led to a need for a more comprehensive understanding of cannabis constituents and their potential for drug-drug interactions. Although (-)-trans-Δ9-tetrahydrocannabinol (THC), cannabidiol (CBD), and cannabinol (CBN) are the most abundant cannabinoids present in cannabis, THC metabolites are found in plasma at higher concentrations and for a longer duration than that of the parent cannabinoids. To understand the potential for drug-drug interactions, the inhibition potential of major cannabinoids and their metabolites on major hepatic cytochrome P450 (P450) enzymes was examined. In vitro assays with P450-overexpressing cell microsomes demonstrated that the major THC metabolites 11-hydroxy-Δ9-tetra-hydrocannabinol and 11-nor-9-carboxy-Δ9-THC-glucuronide competitively inhibited several major P450 enzymes, including CYP2B6, CYP2C9, and CYP2D6 (apparent Ki,u values = 0.086 ± 0.066 µM and 0.90 ± 0.54 µM, 0.057 ± 0.044 µM and 2.1 ± 0.81 µM, 0.15 ± 0.067 µM and 2.3 ± 0.54 µM, respectively). 11-Nor-9-carboxy-Δ9- tetrahydrocannabinol exhibited no inhibitory activity against any CYP450 tested. THC competitively inhibited CYP1A2, CYP2B6, CYP2C9, and CYP2D6; CBD competitively inhibited CYP3A4, CYP2B6, CYP2C9, CYP2D6, and CYP2E1; and CBN competitively inhibited CYP2B6, CYP2C9, and CYP2E1. THC and CBD showed mixed-type inhibition for CYP2C19 and CYP1A2, respectively. These data suggest that cannabinoids and major THC metabolites are able to inhibit the activities of multiple P450 enzymes, and basic static modeling of these data suggest the possibility of pharmacokinetic interactions between these cannabinoids and xenobiotics extensively metabolized by CYP2B6, CYP2C9, and CYP2D6. SIGNIFICANCE STATEMENT: Major cannabinoids and their metabolites found in the plasma of cannabis users inhibit several P450 enzymes, including CYP2B6, CYP2C9, and CYP2D6. This study is the first to show the inhibition potential of the most abundant plasma cannabinoid metabolite, THC-COO-Gluc, and suggests that circulating metabolites of cannabinoids play an essential role in CYP450 enzyme inhibition as well as drug-drug interactions.

Cannabinoids and Cancer Chemotherapy-Associated Adverse Effects

The use of cannabis is not unfamiliar to many cancer patients, as there is a long history of its use for cancer pain and/or pain, nausea, and cachexia induced by cancer treatment. To date, the US Food and Drug Administration has approved 2 cannabis-based pharmacotherapies for the treatment of cancer chemotherapy-associated adverse effects: dronabinol and nabilone. Over the proceeding decades, both research investigating and societal attitudes toward the potential utility of cannabinoids for a range of indications have progressed dramatically. The following monograph highlights recent preclinical research focusing on promising cannabinoid-based approaches for the treatment of the 2 most common adverse effects of cancer chemotherapy: chemotherapy-induced peripheral neuropathy and chemotherapy-induced nausea and vomiting. Both plant-derived and synthetic approaches are discussed, as is the potential relative safety and effectiveness of these approaches in relation to current treatment options, including opioid analgesics.

Cannabinoids in the Treatment of Epilepsy: A Review

Cannabinoids have been studied for their role in the treatment of epilepsy for many years. The U.S. Food and Drug Administration (FDA) approved them for the treatment of some refractory syndromes in 2018. Cannabidiol and tetrahydrocannabinol are the most commonly studied cannabinoids and have been studied in great depth vis-à-vis their pharmacokinetics and pharmacodynamics. Studies have shown the efficacy of cannabinoids in the treatment of refractory epilepsy. A substantial amount of research has been performed exploring the interactions between cannabinoids and other conventional antiseizure medications. The exact mechanisms by which cannabinoids exert their effects on seizure control remain unclear and research into these mechanisms continues in great earnest. Cognitive changes from cannabinoids are constantly being studied and add to potential benefits from the use of these compounds. Cultural and social misconceptions and roadblocks about the use of cannabinoids persist and represent an ongoing obstacle to increasing research and therapeutic use of these compounds. This review focuses on all these aspects and of the use of these cannabinoids in the treatment of epilepsy and seeks to offer a fairly comprehensive description of the facets of cannabinoid therapy for refractory epilepsy.

Development and Verification of a Linked Δ 9-THC/11-OH-THC Physiologically Based Pharmacokinetic Model in Healthy, Nonpregnant Population and Extrapolation to Pregnant Women

Conducting clinical trials to understand the exposure risk/benefit relationship of cannabis use is not always feasible. Alternatively, physiologically based pharmacokinetic (PBPK) models can be used to predict exposure of the psychoactive cannabinoid (-)-Δ9-tetrahydrocannabinol (THC) and its active metabolite 11-hydroxy-Δ9-tetrahydrocannabinol (11-OH-THC). Here, we first extrapolated in vitro mechanistic pharmacokinetic information previously quantified to build a linked THC/11-OH-THC PBPK model and verified the model with observed data after intravenous and inhalation administration of THC in a healthy, nonpregnant population. The in vitro to in vivo extrapolation of both THC and 11-OH-THC disposition was successful. The inhalation bioavailability (Finh) of THC after inhalation was higher in chronic versus casual cannabis users (Finh = 0.35 and 0.19, respectively). Sensitivity analysis demonstrated that 11-OH-THC but not THC exposure was sensitive to alterations in hepatic intrinsic clearance of the respective compound. Next, we extrapolated the linked THC/11-OH-THC PBPK model to pregnant women. Simulations showed that THC plasma area under the curve (AUC) does not change during pregnancy, but 11-OH-THC plasma AUC decreases by up to 41%. Using a maternal-fetal PBPK model, maternal and fetal THC serum concentrations were simulated and compared with the observed THC serum concentrations in pregnant women at term. To recapitulate the observed THC fetal serum concentrations, active placental efflux of THC needed to be invoked. In conclusion, we built and verified a linked THC/11-OH-THC PBPK model in healthy nonpregnant population and demonstrated how this mechanistic physiologic and pharmacokinetic platform can be extrapolated to a special population, such as pregnant women. SIGNIFICANCE STATEMENT: Although the pharmacokinetics of cannabinoids have been extensively studied clinically, limited mechanistic pharmacokinetic models exist. Here, we developed and verified a physiologically based pharmacokinetic (PBPK) model for (-)-Δ9-tetrahydrocannabinol (THC) and its active metabolite, 11-hydroxy-Δ9-tetrahydrocannabinol (11-OH-THC). The PBPK model was verified in healthy, nonpregnant population after intravenous and inhalation administration of THC, and then extrapolated to pregnant women. The THC/11-OH-THC PBPK model can be used to predict exposure in special populations, predict drug-drug interactions, or impact of genetic polymorphism.

Sex differences in the acute effects of oral and vaporized cannabis among healthy adults

Policy changes have increased access to cannabis for individuals with little or no prior exposure. Few studies have examined sex differences in cannabis effects among individuals with sporadic cannabis use or for nonsmoked routes of cannabis administration. Data from four double-blind, placebo-controlled studies were pooled to compare the acute pharmacodynamic effects of vaporized and oral cannabis in male (n = 27) and female (n = 23) participants who used cannabis infrequently (no use ≥30 days prior to randomization). Analyses compared peak change-from-baseline scores between male and female participants for subjective drug effects, cognitive/psychomotor performance, cardiovascular effects, and blood concentrations of Δ9-tetrahydrocannabinol (THC) and its primary metabolites (11-OH-THC, THC-COOH) after exposure to placebo cannabis or cannabis containing low-dose (5 or 10 mg) or high-dose THC (20 or 25 mg). Overall, cannabis elicited dose-orderly increases in subjective effects, impairment of cognitive/psychomotor performance, heart rate, and blood cannabinoid concentrations. Females exhibited greater peak blood 11-OH-THC concentrations and reported greater peak subjective ratings of "drug effect" that remained when controlling for body weight. When controlling for both body weight and peak blood cannabinoid concentrations, ratings of "anxious/nervous," "heart racing," and "restless" were significantly higher for females than males. Although additional research is needed to elucidate sex differences in responses to cannabis at a wider range of THC doses, other routes of administration, and products with diverse chemical composition, the current data indicate that public health messaging and clinical decision making around the use of cannabinoids should recommend lower starting doses for females and warnings about acute anxiogenic reactions.

The embodiment of wastewater data for the estimation of illicit drug consumption in Spain

Data obtained from wastewater analysis can provide rapid and complementary insights in illicit drug consumption at community level. Within Europe, Spain is an important country of transit of both cocaine and cannabis. The quantity of seized drugs and prevalence of their use rank Spain at the top of Europe. Hence, the implementation of a wastewater monitoring program at national level would help to get better understanding of spatial differences and trends in use of illicit drugs. In this study, a national wastewater campaign was performed for the first time to get more insight on the consumption of illicit drugs within Spain. The 13 Spanish cities monitored cover approximately 6 million inhabitants (12.8% of the Spanish population). Untreated wastewater samples were analyzed for urinary biomarkers of amphetamine, methamphetamine, MDMA, cocaine, and cannabis. In addition, weekend samples were monitored for 17 new psychoactive substances. Cannabis and cocaine are the most consumed drugs in Spain, but geographical variations showed, for instance, comparatively higher levels of methamphetamine in Barcelona and amphetamine in Bilbao, with about 1-fold higher consumption of these two substances in such metropolitan areas. For amphetamine, an enantiomeric profiling was performed in order to assure the results were due to consumption and not to illegal dumping of production residues. Furthermore, different correction factors for the excretion of cannabis were used to compare consumption estimations. All wastewater results were compared with previously reported data, national seizure data and general population survey data, were a reasonable agreement was found. Daily and yearly drug consumption were extrapolated to the entire Spanish population with due precautions because of the uncertainty associated. These data was further used to estimate the retail drug market, where for instance cocaine illicit consumption alone was calculated to contribute to 0.2-0.5% of the Spanish gross domestic product (ca. 3000-6000 million Euro/year).