A phase 1, randomized, pharmacokinetic trial of the effect of different meal compositions, whole milk, and alcohol on cannabidiol exposure and safety in healthy subjects

Infant formula as a solid lipid dose form for enhancement of the oral bioavailability of cannabidiol for paediatric patients

Cannabinoids can save paediatric patients from harmful psychological conditions caused by epilepsy. However, the limited aqueous solubility of the drug presents a limitation to oral absorption and bioavailability. Previous studies have shown the enhancement of oral bioavailability for poorly water-soluble drugs using milk or milk-based products like infant formula as a novel lipid-based formulation, due to digestion of the lipids to enhance drug solubility. that is particularly well suited to infants and in low economy settings. Therefore, this study has investigated the in vitro solubilization enhancement of cannabidiol (CBD) in milk-based products during digestion using synchrotron small angle X-ray scattering, followed by pharmacokinetic studies to determine the relative oral bioavailability. The in vitro results, coupled with in vivo data, demonstrate a two-fold increase in the oral bioavailability of CBD in bovine milk as well as infant formula. The results of this study indicate the potential for infant formula to be considered as a novel formulation approach for CBD. Further study is encouraged for more drugs with infant formula to strengthen the correlation between the solubilization of drug and their oral bioavailability.

Cannabidiol and its Potential Evidence-Based Psychiatric Benefits - A Critical Review

The endocannabinoid system shows promise as a novel target for treating psychiatric conditions. Cannabidiol (CBD), a naturally occurring cannabinoid, has been investigated in several psychiatric conditions, with diverse effects and an excellent safety profile compared to standard treatments. Even though the body of evidence from randomised clinical trials is growing, it remains relatively limited in most indications. This review comprises a comprehensive literature search to identify clinical studies on the effects of CBD in psychiatric conditions. The literature search included case studies, case reports, observational studies, and RCTs published in English before July 27, 2023, excluding studies involving nabiximols or cannabis extracts containing CBD and ∆9-tetrahydrocannabinol. Completed studies were considered, and all authors independently assessed relevant publications.Of the 150 articles identified, 54 publications were included, covering the effects of CBD on healthy subjects and various psychiatric conditions, such as schizophrenia, substance use disorders (SUDs), anxiety, post-traumatic stress disorder (PTSD), and autism spectrum disorders. No clinical studies have been published for other potential indications, such as alcohol use disorder, borderline personality disorder, depression, dementia, and attention-deficit/hyperactivity disorder. This critical review highlights that CBD can potentially ameliorate certain psychiatric conditions, including schizophrenia, SUDs, and PTSD. However, more controlled studies and clinical trials, particularly investigating the mid- to long-term use of CBD, are required to conclusively establish its efficacy and safety in treating these conditions. The complex effects of CBD on neural activity patterns, likely by impacting the endocannabinoid system, warrant further research to reveal its therapeutic potential in psychiatry.

Cannabidiol Bioavailability Is Nonmonotonic with a Long Terminal Elimination Half-Life: A Pharmacokinetic Modeling-Based Analysis

Background: Oral and inhalation-based cannabidiol (CBD) administration has been clinically evaluated for various therapeutic indications, alongside widespread off-label use. However, the long-term exposure kinetics and varied bioavailability have not been fully characterized. Methods: Human CBD plasma concentration-time profiles from six studies evaluating the oral administration of Epidiolex® and three studies evaluating inhalation-based delivery were obtained. A four-compartment pharmacokinetic (PK) model with Weibull-based oral absorption kinetics was employed to describe the long-term PKs of CBD. Furthermore, a Cedergreen-Ritz-Streibig model was applied to evaluate nonmonotonic oral bioavailability. Results: CBD was extensively distributed into tissue compartments with varied kinetics resulting in a long plasma terminal elimination half-life of >134 h in humans. For once-a-day oral dosing, the plasma trough concentrations require >70 days to reach a steady state. The oral bioavailability of CBD for different doses administered in fasted state follows a nonmonotonic pattern with an inverted U-shaped profile. Oral administration of CBD under fed state or subjects with hepatic impairment yields higher oral bioavailability with varied exposure. In contrast, inhalation-based delivery of CBD, while delivering a similar systemic delivered dose compared with oral dosing due to high device losses, bypasses first-pass metabolism and can be efficient. Conclusion: CBD PKs vary across different doses due to nonmonotonic oral bioavailability, and inhalation-based delivery could minimize such variability in humans. The delayed attainment of steady state and prolonged terminal half-life, resulting from differential but extensive tissue distribution, needs to be considered when dosing CBD in the long term. These fundamental findings are critical for establishing dose-exposure relationship for further clinical evaluation of novel CBD-based therapies.

Pharmacokinetics and tolerability of single-dose enteral cannabidiol and cannabidiolic acid rich hemp in horses (Equus caballus)

The pharmacokinetics and tolerability of cannabinoids and their metabolites were determined in eight horses after enteral administration of a commercial CBD/CBDA-rich hemp oil product. Each horse was administered 2 mg/kg or 8 mg/kg CBD/CBDA or no treatment in a randomized cross-over design. Serial serum samples collected over 48 h were analyzed by high performance liquid chromatography with tandem mass spectrometry. Plasma chemistry analysis was performed at 0 h and 24 h. Vital parameters, pedometry, and blinded mentation and gait evaluations were recorded at intervals up to 24 h. Manure production and gastrointestinal transit time were tracked for 48 h after oil administration. The median maximal concentration of CBD and CBDA were 5.2 and 36.95 ng/mL in the 2 mg/kg group, respectively; and 40.35 and 353.56 ng/mL in the 8 mg/kg group. The median half-life of elimination was not calculated for the 2 mg/kg CBD treatment due to lack of time points above the lower quantifiable limit beyond the Cmax while it was 7.75 h in the 8 mg/kg group. CBDA absorption was biphasic. Pharmacokinetic parameters for tetrahydrocannabinol, tetrahydrocannabinolic acid, cannabigerolic acid, and 7-carboxy cannabidiol are also reported. No significant differences in any of the measured tolerability parameters were demonstrated between treatment groups. Single-dose enteral administration of CBD/CBDA-rich hemp extract up to 8 mg/kg does not appear to produce neurologic, behavioral, or gastrointestinal effects in horses.

Interactions between antiseizure medications and foods and drinks: A systematic review

Antiseizure medications (ASMs) constitute the principal of treatment for patients with epilepsy, where long-term treatment is usually necessary. The purpose of this systematic review is to provide practical and useful information regarding various aspects of the interactions between ASMs and foods and drinks. MEDLINE and ScienceDirect, from the inception to July 15, 2023, were searched for related publications. In both electronic databases, the following search strategy was applied, and the following keywords were used (in title/abstract): "food OR drink" AND "antiepileptic OR antiseizure." The primary search yielded 738 studies. After implementing our inclusion and exclusion criteria, we could identify 19 studies on the issue of interest for our endeavor. Four studies were identified in the recheck process and not by the primary search. All studies provided low level of evidence. Interactions between foods and ASMs are a common phenomenon. Many factors may play a role for such an interaction to come to play; these include drug properties, administration route, and administration schedule, among others. Drugs-foods (-drinks) interactions may change the drug exposure or plasma levels of drugs (e.g., grapefruit juice increases carbamazepine concentrations and the bioavailability of cannabidiol is increased 4-5 folds with concomitant intake of fat-rich food); this may require dosage adjustments. Interactions between ASMs and foods and drinks may be important. This should be taken seriously into consideration when consulting patients and their caregivers about ASMs. Future well-designed investigations should explore the specific interactions between foods (and drinks) and ASMs to clarify whether they are clinically important. PLAIN LANGUAGE SUMMARY: Interactions between antiseizure medications and foods and drinks may be important. This should be taken into consideration in patients with epilepsy.

CBD and THC in Special Populations: Pharmacokinetics and Drug-Drug Interactions

Cannabinoid use has surged in the past decade, with a growing interest in expanding cannabidiol (CBD) and delta-9-tetrahydrocannabinol (THC) applications into special populations. Consequently, the increased use of CBD and THC raises the risk of drug-drug interactions (DDIs). Nevertheless, DDIs for cannabinoids, especially in special populations, remain inadequately investigated. While some clinical trials have explored DDIs between therapeutic drugs like antiepileptic drugs and CBD/THC, more potential interactions remain to be examined. This review summarizes the published studies on CBD and THC-drug interactions, outlines the mechanisms involved, discusses the physiological considerations in pharmacokinetics (PK) and DDI studies in special populations (including pregnant and lactating women, pediatrics, older adults, patients with hepatic or renal impairments, and others), and presents modeling approaches that can describe the DDIs associated with CBD and THC in special populations. The PK of CBD and THC in special populations remain poorly characterized, with limited studies investigating DDIs involving CBD/THC in these populations. Therefore, it is critical to evaluate potential DDIs between CBD/THC and medications that are commonly used in special populations. Modeling approaches can aid in understanding these interactions.

A randomized, double-blind, placebo-controlled, repeated-dose pilot study of the safety, tolerability, and preliminary effects of a cannabidiol (CBD)- and cannabigerol (CBG)-based beverage powder to support recovery from delayed onset muscle soreness (DOMS)

BACKGROUND

Cannabinoid-containing products are marketed to athletes as promoting recovery, in spite of a lack of data on their safety and effects. This randomized, double-blind, placebo-controlled, repeated-dose pilot study tested the safety, tolerability, and preliminary effects on recovery of a formulation containing cannabidiol (CBD; 35 mg), cannabigerol (CBG; 50 mg), beta caryophyllene (BCP; 25 mg), branched-chain amino acids (BCAAs; 3.8 g), and magnesium citrate (420 mg).

METHODS

Exercise-trained individuals (N = 40) underwent an experimental induction of delayed onset muscle soreness (DOMS) and completed follow-up visits 24-, 48-, and 72-hours post-DOMS. Participants were randomized to active or placebo formulation, and consumed the formulation twice per day for 3.5 days.

RESULTS

There was one adverse event (AE) in the active group (diarrhea) and two AEs in placebo (dry mouth; eye rash/swollen eye). There was 100% self-reported compliance with formulation consumption across the two groups. For the primary outcome of interest, the estimate of effect for ratings of average soreness/discomfort 72 hours post-DOMS between active and placebo groups was -1.33 (85% confidence interval = -2.55, -0.10), suggesting moderate evidence of a treatment difference. The estimate of effect for the outcome of ratings of interference of soreness, discomfort, or stiffness on daily activities at work or home 48 hours post-DOMS was -1.82 (95% confidence interval = -3.64, -0.01), indicating a treatment difference of potential clinical importance. There was no significant effect between active and placebo groups on objective measures of recovery, sleep quality, or mood disturbance.

CONCLUSIONS

The tested formulation reduced interference of DOMS on daily activities, demonstrating its improvement on a functional aspect of recovery.

Subtype-specific modulation of human KV 7 channels by the anticonvulsant cannabidiol through a lipid-exposed pore-domain site

BACKGROUND AND PURPOSE

Cannabidiol (CBD) is used clinically as an anticonvulsant. Its precise mechanism of action has remained unclear. CBD was recently demonstrated to enhance the activity of the neuronal KV 7.2/7.3 channel, which may be one important contributor to CBD anticonvulsant effect. Curiously, CBD inhibits the closely related cardiac KV 7.1/KCNE1 channel. Whether and how CBD affects other KV 7 subtypes remains uninvestigated and the CBD interaction sites mediating these diverse effects remain unknown.

EXPERIMENTAL APPROACH

Here, we used electrophysiology, molecular dynamics simulations, molecular docking and site-directed mutagenesis to address these questions.

KEY RESULTS

We found that CBD modulates the activity of all human KV 7 subtypes and that the effects are subtype dependent. CBD enhanced the activity of KV 7.2-7.5 subtypes, seen as a V50 shift towards more negative voltages or increased maximum conductance. In contrast, CBD inhibited the KV 7.1 and KV 7.1/KCNE1 channels, seen as a V50 shift towards more positive voltages and reduced conductance. In KV 7.2 and KV 7.4, we propose a CBD interaction site at the subunit interface in the pore domain that overlaps with the interaction site of other compounds, notably the anticonvulsant retigabine. However, CBD relies on other residues for its effects than the conserved tryptophan that is critical for retigabine effects. We propose a similar, though not identical CBD site in KV 7.1, with a non-conserved phenylalanine being important.

CONCLUSIONS AND IMPLICATIONS

We identify novel targets of CBD, contributing to a better understanding of CBD clinical effects and provide mechanistic insights into how CBD modulates different KV 7 subtypes.

Assessing Liver Effects of Cannabidiol and Valproate Alone and in Combination Using Quantitative Systems Toxicology

In clinical trials of cannabidiol (CBD) for the treatment of seizures in patients with Dravet syndrome, Lennox-Gastaut syndrome, and tuberous sclerosis complex, elevations in serum alanine aminotransferase (ALT) > 3× the upper limit of normal were observed in some patents, but the incidence was much greater in patients who were receiving treatment with valproate (VPA) before starting CBD. To explore potential mechanisms underlying this interaction, we used DILIsym, a quantitative systems toxicology model, to predict ALT elevations in a simulated human population treated with CBD alone, VPA alone, and when CBD dosing was starting during treatment with VPA. We gathered in vitro data assessing the potential for CBD, the two major CBD metabolites, and VPA to cause hepatotoxicity via inhibition of bile acid transporters, mitochondrial dysfunction, and production of reactive oxygen species (ROS). Physiologically-based pharmacokinetic models for CBD and VPA were used to predict liver exposure. DILIsym simulations predicted dose-dependent ALT elevations from CBD treatment and this was predominantly driven by ROS production from the parent molecule. DILIsym also predicted VPA treatment to cause ALT elevations which were transient when mitochondrial biogenesis was incorporated into the model. Contrary to the clinical experience, simulation of 2 weeks treatment with VPA prior to introduction of CBD treatment did not predict an increase of the incidence of ALT elevations relative to CBD treatment alone. We conclude that the marked increased incidence of CBD-associated ALT elevations in patients already receiving VPA is unlikely to involve the three major mechanisms of direct hepatotoxicity.

Cannabidiol Exposure Through Maternal Marijuana Use: Predictions in Breastfed Infants

BACKGROUND AND OBJECTIVE

Knowledge about exposure to cannabidiol (CBD) in breastfed infants can provide an improved understanding of potential risk. The aim was to predict CBD exposure in breastfed infants from mothers taking CBD and CBD-containing products.

METHODS

Cannabidiol concentrations in milk previously attained from data collected through an existing human milk research biorepository were used to simulate infant doses and identify subgroups. A developed pediatric physiologically based pharmacokinetic model produced virtual breastfed infants administered the simulated CBD doses. Predicted breastfed infant exposures and upper area under the curve ratios were compared to the lowest therapeutic dose for approved indications in children.

RESULTS

The existing human milk research biorepository contained 200 samples from 181 unique breastfeeding mothers for whom self-reported administration data and CBD concentrations had previously been measured. Samples that were above the lower limit of quantification with only one maternal administration type revealed that administration type, i.e., joint/blunt or edible versus oil or pipe, resulted in significantly different subgroups in terms of milk concentrations. Resulting simulated infant doses (ng/kg) were described by lognormal distributions with geometric means and geometric standard deviations: 0.61 ± 2.41 all concentrations, 0.10 ± 0.37 joint/blunt or edible, and 2.23 ± 8.15 oil or pipe. Doses administered to breastfed infants had exposures magnitudes lower than exposures in children aged 4-11 years administered the lowest therapeutic dose for approved indications, and low upper area under the curve ratios.

CONCLUSIONS

Based on real-world use, breastfeeding infants are predicted to receive very small exposures of CBD through milk. Studies examining adverse reactions will provide further insight into potential risk.

Cannabidiol and Intestinal Motility: a Systematic Review

Cannabidiol (CBD) is a non-intoxicating cannabinoid extracted from the cannabis plant that is used for medicinal purposes. Ingestion of CBD is claimed to address several pathologies, including gastrointestinal disorders, although limited evidence has been generated thus far to substantiate many of its health claims. Nevertheless, CBD usage as an over-the-counter treatment for gastrointestinal disorders is likely to expand in response to increasing commercial availability, permissive legal status, and acceptance by consumers. This systematic review critically evaluates the knowledge boundaries of the published research on CBD, intestinal motility, and intestinal motility disorders. Research on CBD and intestinal motility is currently limited but does support the safety and efficacy of CBD for several therapeutic applications, including seizure disorders, inflammatory responses, and upper gastrointestinal dysfunction (i.e., nausea and vomiting). CBD, therefore, may have therapeutic potential for addressing functional gastrointestinal disorders. The results of this review show promising in vitro and preclinical data supporting a role of CBD in intestinal motility. This includes improved gastrointestinal-related outcomes in murine models of colitis. These studies, however, vary by dose, delivery method, and CBD-extract composition. Clinical trials have yet to find a conclusive benefit of CBD on intestinal motility disorders, but these trials have been limited in scope. In addition, critical factors such as CBD dosing parameters have not yet been established. Further research will establish the efficacy of CBD in applications to address intestinal motility.

Cannabidiol Oil Ingested as Sublingual Drops or Within Gelatin Capsules Shows Similar Pharmacokinetic Profiles in Healthy Males

Introduction: Cannabidiol (CBD) is a nonintoxicating phytocannabinoid used in clinical treatments and sold widely in consumer products. CBD products may be designed for sublingual or oral delivery, but it is unclear whether either is advantageous for CBD absorption. This study compared CBD pharmacokinetics after providing CBD oil as sublingual drops and within orally ingested gelatin capsules, at a dose relevant to consumer products. Materials and Methods: Eight males completed three conditions in a participant-blinded, randomized crossover design. Participants received the following combinations of placebo and CBD-containing (69 mg/mL) hemp oil in capsules and as sublingual drops: placebo capsules/placebo drops (Placebo), CBD capsules/placebo drops (CBD-Caps), and placebo capsules/CBD drops (CBD-Drops). Blood samples, blood pressure, and subjective scales were obtained/completed hourly for 6 h and at 24 h. Discussion: Plasma CBD concentrations were not different between CBD-Caps and CBD-Drops (interaction effect p=0.76). Peak CBD concentration (28.0±15.6 vs. 24.0±22.2 ng/mL), time of peak CBD concentration (4±1 vs. 4±2 h), and area under the concentration curve (45.3±20.3 vs. 41.8±23.3 ng/mL·6 h) were not different between conditions (p≥0.25). Cardiometabolic outcomes (plasma glucose/triacylglycerol, heart rate, blood pressure), liver function (plasma alanine aminotransferase/aspartate aminotransferase), kidney function (plasma creatinine), and subjective feelings/symptoms were not different between conditions (p≥0.07). Conclusions: Plasma CBD profiles were comparable between CBD-Caps and CBD-Drops, suggesting that there were not meaningful differences in routes of CBD absorption between conditions. This implies that CBD oil delivered sublingually is swallowed before oral mucosal CBD absorption occurs, which may have implications for research design, CBD product design, and consumer product choice.

A Two-Phase, Dose-Ranging, Placebo-Controlled Study of the Safety and Preliminary Test of Acute Effects of Oral Δ8-Tetrahydrocannabivarin in Healthy Participants

Introduction: Tetrahydrocannabivarin (THCV) is an understudied cannabinoid that appears to have effects that vary as a function of dose. No human study has evaluated the safety and nature of effects in a wide range of THCV doses. Methods: This was a two-phase, dose-ranging, placebo-controlled trial of the Δ8 isomer of oral THCV in healthy adults. Phase 1 utilized an unblinded, single-ascending dose design (n=3). Phase 2 used a double-blind, randomized, within-participant crossover design (n=18). Participants received single acute doses of placebo and 12.5, 25, 50, 100, and 200 mg of THCV. Safety measures and subjective and cognitive effects were assessed predose and up to 8 h postdose. Results: Most adverse events (AEs; 55/60) were mild. Euphoric mood was the most common AE. The 12.5, 25, and 200 mg doses produced significantly lower minimum times to complete the digit vigilance test (ps=0.01). The 25 mg dose showed elevations on mean ratings of "energetic" at 1-, 2-, and 4-h postdose, but the maximum postdose rating for this dose did not achieve statistical significance relative to placebo ([95% confidence interval]=3.2 [-0.5 to 6.9], p=0.116). The 100 and 200 mg doses showed elevations on ratings of "feel a drug effect" and "like the drug effect." Almost all urine drug screens (78/79) at 8 h postdose in the active THCV conditions tested positive for tetrahydrocannabinol (THC). Conclusion: All THCV doses displayed a favorable safety profile. Several THCV doses showed a preliminary signal for improved sustained attention, but the effect was not dose dependent. Though mild and not associated with impairment, THC-like effects were observed at higher THCV doses. Oral THCV-containing products could lead to positive urine drug screens for THC. ClinicalTrials.gov ID: NCT05210634.

Pharmacokinetics of Cannabidiol: A Systematic Review and Meta-Regression Analysis

Background: In this review, we provide an updated assessment of available evidence on the pharmacokinetics (PK) of CBD and explore the impact of different factors on PK outcomes. Materials and Methods: This systematic review and meta-regression analysis was preregistered (PROSPERO: CRD42021269857). We systematically searched Medline, Embase, PsycInfo, and Web of Science Core Collection up to November 19, 2022. Trials of CBD in healthy adults were included if they reported at least one of the PK parameters of interest, including Tmax, Cmax, AUC0-t, AUC0-inf, and T1/2, in serum or plasma. Studies of patient populations or CBD co-administration with other medications were excluded. The National Heart, Lung, and Blood Institute's Quality Assessment Tool for Before-After Studies with no Control Group was used. Random-effects multivariable meta-regression analysis was conducted. Results: A total of 112 trial arms from 39 studies were included; 26 trial arms had a "Good" quality, 70 "Fair," and 16 "Poor." Eight arms used inhalation CBD, 29 oromucosal, 73 oral, and 2 intravenous. CBD formulations could be categorized to nanotech (n=14), oil-based (n=21), alcohol-based (n=10), water-based (n=12), Sativex (n=17), and Epidiolex® (n=22). For single-dose studies, CBD doses ranged between 2 and 100 mg in inhalation, 5-50 mg in oromucosal, and 0.42-6000 mg in oral administration. Sixty-six trial arms had only male participants or a higher number of male than female participants. The duration of the PK session was between 4 and 164 h. A higher CBD dose was associated with higher Cmax, AUC0-t, and AUC0-inf. Compared with oral administration, oromucosal administration was associated with lower Cmax, AUC0-t, and AUC0-inf. Fed status was associated with higher Cmax and AUC0-t when compared with the fasting status. A higher ratio of female participants was associated with lower Tmax in oral administration and higher Cmax. Conclusion: As expected, CBD dose, route of administration, and diet were major determinants of CBD PK with oral routes providing higher bioavailability and nanotechnology formulations a faster onset. Although CBD appeared to have a faster onset and longer duration in women, more studies are required to delineate the role of biological sex. Factors that influence CBD PK have implications for medication development and appropriate dosing in clinical practice.

Real-World Evidence of Factors Affecting Cannabidiol Exposure in Children with Drug-Resistant Developmental and Epileptic Encephalopathies

The identification of factors that affect cannabidiol (CBD) systemic exposure may aid in optimizing treatment efficacy and safety in clinical practice. In this study, we aimed to correlate CBD plasma concentrations at a steady state to demographic, clinical, and pharmacological characteristics as well as seizure frequency after the administration of a purified CBD oil solution in a real-world setting of children with drug-resistant developmental and epileptic encephalopathies (DEEs). Patients receiving oral CBD pharmaceutical products at maintenance were enrolled. Venous blood samples were drawn before the CBD morning dose, 12 h apart from the last evening dose (C0 or CBD trough concentration). A linear mixed-effect analysis was implemented to assess the correlation between C0 and clinical, laboratory, pharmacological, and lifestyle factors. Fifteen females and seven males with a median age of 12.8 years (ranging between 4.7 and 17.2) were included. The median CBD dose was 8.8 mg/kg/day (ranging between 2.6 and 22.5), and the CBD C0 median (range) was 48.2 ng/mL (3.5-366.3). The multivariate model showed a 109.6% increase in CBD C0 in patients with concomitant levothyroxine (β = 0.74 ± 0.1649, p < 0.001), 56.8% with food (β = 0.45 ± 0.1550, p < 0.01), and 116.0% after intake of a ketogenic diet (β = 0.77 ± 0.3141, p < 0.05). All patients included were responders without evidence of an association between C0 and response status. In children with DEEs, systemic concentrations of CBD may be significantly increased when co-administered with levothyroxine, food, or a ketogenic diet.

Measuring the diversity gap of cannabis clinical trial participants compared to people who report using cannabis

Little is known about the demographics of people who use cannabis, including how use trends within population subgroups have evolved over time. It is therefore challenging to know if the demographics of participants enrolled in cannabis clinical trials are representative of those who use cannabis. To fill this knowledge gap, data from the National Survey on Drug Use and Health (NSDUH) on "past-month" cannabis use across various population subgroups in the United States was examined from 2002 to 2021. The most notable increases in "past-month" cannabis use prevalence occurred in those aged 65 and older (2,066.1%) and 50-64-year-olds (472.4%). In 2021, people reporting "past-month" cannabis use were 56.6% male and 43.4% female. Distribution across self-reported race and ethnicity was 64.1% White, 14.3% Black, 14.1% Hispanic, and 3.1% more than one race. And many ages were represented as 24.4% were 26-34, 24.1% were 35-49, 22.4% were 18-25, and 17.6% were 50-64 years old. To understand if these population subgroups are represented in cannabis clinical trials, participant demographics were extracted from peer-reviewed clinical trials reporting on pharmacokinetic and/or pharmacodynamic models of cannabis or cannabinoids. Literature was grouped by publication year (2000-2014 and 2015-2022) and participant prior exposure to cannabis. Results identified that cannabis clinical trial participants are skewed toward overrepresentation by White males in their 20s and 30s. This represents structural discrimination in the research landscape that perpetuates social and health inequities.

Cannabidiol as a candidate pharmacotherapy for sleep disturbance in alcohol use disorder

Among individuals with alcohol use disorder (AUD), it is estimated that the majority suffer from persistent sleep disturbances for which few candidate medications are available. Our aim wass to critically review the potential for cannabidiol (CBD) as a treatment for AUD-induced sleep disturbance. As context, notable side effects and abuse liability for existing medications for AUD-induced sleep disturbance reduce their clinical utility. CBD modulation of the endocannabinoid system and favorable safety profile have generated substantial interest in its potential therapeutic use for various medical conditions. A number of preclinical and clinical studies suggest promise for CBD in restoring the normal sleep-wake cycle and in enhancing sleep quality in patients diagnosed with AUD. Based on its pharmacology and the existing literature, albeit primarily preclinical and indirect, CBD is a credible candidate to address alcohol-induced sleep disturbance. Well-designed RCTs will be necessary to test its potential in managing this challenging feature of AUD.

A cross-sectional survey on cannabis: Characterizing motives, opinions, and subjective experiences associated with the use of various oral cannabis products

BACKGROUND

Cannabis-infused products available for oral consumption include food and drink items (i.e., edibles) (e.g., baked goods, gummy-, chocolate-, and hard-candies, beverages/drinks) as well as non-food formulations (e.g., oils/tinctures, pills/capsules). This study characterized the motives, opinions, and subjective experiences associated with the use of these seven subtypes of oral cannabis products.

METHODS

This web-based survey collected cross-sectional, self-report data from a convenience sample of 370 adults regarding various use-motives, self-reported cannabinoid content, subjective experiences, and opinions related to ingesting oral cannabis products with alcohol and/or food. Advice participants had received about modifying oral cannabis product effects, in general, was also collected.

RESULTS

Participants reported consuming cannabis baked goods and gummy candies most frequently over the past year (68% and 63%, respectively). Participants were less likely to use oils/tinctures for enjoyment/desire relative to other product types and more likely to use oils/tinctures for therapeutic purposes (e.g., medication-replacement). Self-reported cannabinoid content was highly variable across participants and within product subtype. Participants reported feeling stronger and longer-lasting effects when consuming oral cannabis products on an empty stomach and 43% received advice to "eat a snack or meal" to mitigate effects that are too strong, which contrasts with controlled studies. Finally, 43% of participants reported modifying their experiences with alcohol at least some of time.

CONCLUSIONS

These findings underscore the need to further evaluate use-motives as well as the interaction between dietary factors, cannabinoid pharmacokinetics, and subjective drug effects and the interactive effects of oral cannabis products and alcohol in a controlled laboratory setting.

An Individuality of Response to Cannabinoids: Challenges in Safety and Efficacy of Cannabis Products

Since legalization, cannabis/marijuana has been gaining considerable attention as a functional ingredient in food. ∆-9 tetrahydrocannabinol (THC), cannabidiol (CBD), and other cannabinoids are key bioactive compounds with health benefits. The oral consumption of cannabis transports much less hazardous chemicals than smoking. Nevertheless, the response to cannabis is biphasically dose-dependent (hormesis; a low-dose stimulation and a high-dose inhibition) with wide individuality in responses. Thus, the exact same dose and preparation of cannabis may be beneficial for some but toxic to others. The purpose of this review is to highlight the concept of individual variations in response to cannabinoids, which leads to the challenge of establishing standard safe doses of cannabis products for the general population. The mechanisms of actions, acute and chronic toxicities, and factors affecting responses to cannabis products are updated. Based on the literature review, we found that the response to cannabis products depends on exposure factors (delivery route, duration, frequency, and interactions with food and drugs), individual factors (age, sex), and susceptibility factors (genetic polymorphisms of cannabinoid receptor gene, N-acylethanolamine-hydrolyzing enzymes, THC-metabolizing enzymes, and epigenetic regulations). Owing to the individuality of responses, the safest way to use cannabis-containing food products is to start low, go slow, and stay low.

Verifying in vitro-determined enzyme contributions to cannabidiol clearance for exposure predictions in human through physiologically-based pharmacokinetic modeling

Cannabidiol (CBD) is approved for treatment of seizures associated with two forms of epilepsy that become apparent in infancy or early childhood. To consider an adult physiologically-based pharmacokinetic (PBPK) model for pediatric scaling, we assessed in vitro-derived cytochrome P450 (CYP) and uridine 5'-diphospho-glucuronosyltransferase (UGT) enzyme contributions to CBD clearance in human. An i.v. PBPK model was constructed using CBD physicochemical properties and knowledge of disposition. The i.v. datasets were used for model building and evaluation. Oral PBPK models for CBD administered in fasted and fed states were developed using single dose oral datasets and parameters optimized from the i.v. model and evaluated with multiple dose datasets. Relative contributions of CBD metabolizing enzymes were partitioned according to in vitro studies. Clinical drug-drug interaction (DDI) studies were simulated using CBD fed state, itraconazole, fluconazole, and rifampicin PBPK models. Linear mixed effect modeling was used to estimate area under the concentration-time curve from zero to infinity (AUC0-∞ ) perpetrator + CBD versus CBD alone. The i.v. and oral datasets used in model evaluation produced acceptable average fold error (AFE) of 1.28 and absolute AFE of 1.65. Relative contributions of drug-metabolizing enzymes to CBD clearance were proposed from in vitro data: UGT1A7 4%, UGT1A9 16%, UGT2B7 10%, CYP3A4 38%, CYP2C19 21%, and CYP2C9 11%. The simulated DDI studies using the in vitro-derived values produced AUC0-∞ treatment ratios comparable to observed: itraconazole 1.24 versus 1.07, fluconazole 1.45 versus 1.22, and rifampicin 0.49 versus 0.69. The constructed CBD PBPK models can predict adult exposures and have potential for use in pediatrics where exposure estimates are limited.

Pharmacokinetics of Cannabidiol: A systematic review and meta-regression analysis

Background

In this review, we provide an updated assessment of available evidence on the pharmacokinetics (PK) of cannabidiol (CBD) and explore the impact of different factors on PK outcomes.

Materials and Methods

This systematic review and meta-regression analysis was pre-registered (PROSPERO: CRD42021269857). We systematically searched Medline, Embase, PsychInfo, and Web of Science Core Collection up to November 19, 2022. Trials of CBD in healthy adults were included if they reported at least one of the PK parameters of interest, including Tmax, Cmax, AUC0-t, AUC0-inf, and T 1/2 , in serum or plasma. Studies of patient populations or CBD co-administration with other medications were excluded. The National Heart, Lung, and Blood Institute's Quality Assessment Tool for Before-After Studies with no Control Group was used. Random-effects multivariable meta-regression analysis was conducted.

Results

A total of 112 trial arms from 39 studies were included; 26 trial arms had a "Good" quality, 70 "Fair," and 16 "Poor." Eight arms used inhalation CBD, 29 oromucosal, 73 oral, and 2 intravenous. CBD formulations could be categorized to nanotech (n=14), oil-based (n=21), alcohol-based (n=10), water-based (n=12), Sativex (n=17), and Epidiolex (n=22). For single-dose studies, CBD doses ranged between 2-100mg in inhalation, 5-50mg in oromucosal, and 0.42-6000mg in oral administration. Sixty-six trial arms had only male participants or a higher number of males than females. The duration of the PK session was between 4h-164h. A higher CBD dose was associated with higher Cmax, AUC0-t, and AUC0-inf. Compared to oral administration, oromucosal administration was associated with lower Cmax, AUC0-t, and AUC0-inf. Fed status was associated with higher Cmax and AUC0-t when compared to the fasting status. A higher ratio of female participants was associated with lower Tmax in oral administration and higher Cmax.

Conclusion

As expected, CBD dose, route of administration, and diet were major determinants of CBD pharmacokinetics with oral routes providing higher bioavailability and nanotechnology formulations a faster onset. Though CBD appeared to have a faster onset and longer duration in females, more studies are required to delineate the role of biological sex. Factors that influence CBD PK have implications for medication development and appropriate dosing in clinical practice.

Update on Cannabidiol Clinical Toxicity and Adverse Effects: A Systematic Review

BACKGROUND

Compelling evidence from preclinical and clinical studies supports the therapeutic role of cannabidiol (CBD) in several medical disorders. We reviewed the scientific evidence on CBD-related toxicity and adverse events (AEs) in 2019, at the beginning of the spike in clinical studies involving CBD. However, CBD safety remained uncertain.

OBJECTIVE

With the benefit of hindsight, we aimed to provide an update on CBD-related toxicity and AEs in humans.

METHODS

A systematic literature search was conducted following PRISMA guidelines. PubMed, Cochrane, and Embase were accessed in October 2022 to identify clinical studies mentioning CBDrelated toxicity/AEs from February 2019 to September 2022. Study design, population characteristics, CBD doses, treatment duration, co-medications, and AEs were compiled.

RESULTS

A total of 51 reports were included. Most studies investigated CBD efficacy and safety in neurological conditions, such as treatment-resistant epilepsies, although a growing number of studies are focusing on specific psychopathological conditions, such as substance use disorders, chronic psychosis, and anxiety. Most studies report mild or moderate severity of AEs. The most common AEs are diarrhea, somnolence, sedation, and upper respiratory disturbances. Few serious AEs have been reported, especially when CBD is co-administered with other classes of drugs, such as clobazam and valproate.

CONCLUSION

Clinical data suggest that CBD is well tolerated and associated with few serious AEs at therapeutic doses both in children and adults. However, interactions with other medications should be monitored carefully. Additional data are needed to investigate CBD's long-term efficacy and safety, and CBD use in medical conditions other than epilepsy syndromes.

Cannabidiol in clinical and preclinical anxiety research. A systematic review into concentration-effect relations using the IB-de-risk tool

BACKGROUND

Preclinical research suggests that cannabidiol (CBD) may have therapeutic potential in pathological anxiety. Dosing guidelines to inform future human studies are however lacking.

AIM

We aimed to predict the therapeutic window for anxiety-reducing effects of CBD in humans based on preclinical models.

METHODS

We conducted two systematic searches in PubMed and Embase up to August 2021, into pharmacokinetic (PK) and pharmacodynamic (PD) data of systemic CBD exposure in humans and animals, which includes anxiety-reducing and potential side effects. Risk of bias was assessed with SYRCLE's RoB tool and Cochrane RoB 2.0. A control group was an inclusion criterion in outcome studies. In human outcome studies, randomisation was required. We excluded studies that co-administered other substances. We used the IB-de-risk tool for a translational integration of outcomes.

RESULTS

We synthesised data from 87 studies. For most observations (70.3%), CBD had no effect on anxiety outcomes. There was no identifiable relation between anxiety outcomes and drug levels across species. In all species (humans, mice, rats), anxiety-reducing effects seemed to be clustered in certain concentration ranges, which differed between species.

DISCUSSION

A straightforward dosing recommendation was not possible, given variable concentration-effect relations across species, and no consistent linear effect of CBD on anxiety reduction. Currently, these results raise questions about the broad use as a drug for anxiety. Meta-analytic studies are needed to quantitatively investigate drug efficacy, including aspects of anxiety symptomatology. Acute and (sub)chronic dosing studies with integrated PK and PD outcomes are required for substantiated dose recommendations.

Pain response to cannabidiol in opioid-induced hyperalgesia, acute nociceptive pain, and allodynia using a model mimicking acute pain in healthy adults in a randomized trial (CANAB II)

ABSTRACT

Opioids in general and remifentanil in particular can induce hyperalgesia. Preclinical data suggest that cannabidiol might have the capacity to reduce opioid-induced hyperalgesia (OIH). Thus, we investigated the effect of oral cannabidiol on OIH in healthy volunteers using an established pain model. Twenty-four healthy participants were included in this randomized, double-blinded, crossover study and received either a 1600-mg single-dose oral cannabidiol or placebo. Hyperalgesia, allodynia, and pain were induced by intracutaneous electrical stimulation. To provoke OIH, participants recieved an infusion of 0.1 µg/kg/min remifentanil over a time frame of 30 minutes, starting 100 minutes after oral cannabidiol ingestion. The primary outcome was the area of hyperalgesia (in square centimetres) up to 60 minutes after remifentanil administration. The area of allodynia (in square centimetres) and pain (numeric rating scale) were also assessed.Cannabidiol had no significant effect on hyperalgesia, allodynia, or pain at any time point of measurement compared with placebo. The area of hyperalgesia after remifentanil administration significantly increased compared with baseline (17.0 cm 2 [8.1-28.7] vs 25.3 cm 2 [15.1-39.6]; P = 0.013). Mean cannabidiol blood levels were 4.1 ± 3.0 µg/L (mean ± SD) at 130 minutes after ingestion and were 8.2 μg/L ± 6.9 µg/L (mean ± SD) at 200 minutes. Cannabidiol was well tolerated. We conclude that a high single-oral dose of 1600-mg cannabidiol is not effective in reducing OIH. Before excluding an effect of cannabidiol on OIH, research should focus on drug formulations enabling higher cannabidiol concentrations.

Regulating for Safety: Cannabidiol Dose in Food: A Review

ABSTRACT

Cannabidiol (CBD) is a nonpsychoactive phytocannabinoid and hemp derivative increasingly used in food. Illegal in food at the U.S. federal level, but legal in some states, the CBD-infused food product market has grown substantially, prompting government concerns regarding potential safety risks. CBD foods are a growing market that is driven by increasing demand from producers and consumers and that is governed by an inconsistent and evolving legal framework. This systematic review of research and regulations identified how legality relates to safety. The research also included an emphasis on dose, a key factor for determining safety in foods. Statutes and guidance documents were reviewed from a selection of jurisdictions with existing or proposed legalized CBD in food to determine what restrictions are used relative to safety, including dose and related standards for food. A search of scientific literature was conducted to evaluate what is known about safe dose in food applications and determine what information is still needed to inform a standard or regulated limit. Findings were analyzed to determine risks and what research and regulations are needed to address them. Legal jurisdictions do little to safeguard consumers against potential risks associated with CBD in food because they focus primarily on warnings and prohibiting health claims. Warning and labeling requirements lack consistency. More concerning is the absence of standards for dose in food or for the composition of the CBD used. Further, there is limited and incomplete information to inform such standards.

HIGHLIGHTS

Pharmacokinetics of Cannabis and Its Derivatives in Animals and Humans During Pregnancy and Breastfeeding

Cannabis is one of the most widely used illicit drugs during pregnancy and lactation. With the recent legalization of cannabis in many countries, health professionals are increasingly exposed to pregnant and breastfeeding women who are consuming cannabis on a regular basis as a solution for depression, anxiety, nausea, and pain. Cannabis consumption during pregnancy can induce negative birth outcomes such as reduced birth weight and increased risk of prematurity and admission to the neonatal intensive care unit. Yet, limited information is available regarding the pharmacokinetics of cannabis in the fetus and newborn exposed during pregnancy and lactation. Indeed, the official recommendations regarding the use of cannabis during these two critical development periods lack robust pharmacokinetics data and make it difficult for health professionals to guide their patients. Many clinical studies are currently evaluating the effects of cannabis on the brain development and base their groups mostly on questionnaires. These studies should be associated with pharmacokinetics studies to assess correlations between the infant brain development and the exposure to cannabis during pregnancy and breastfeeding. Our project aims to review the available data on the pharmacokinetics of cannabinoids in adults, neonates, and animals. If the available literature is abundant in adult humans and animals, there is still a lack of published data on the exposure of pregnant and lactating women and neonates. However, some of the published information causes concerns on the exposure and the potential effects of cannabis on fetuses and neonates. The safety of cannabis use for non-medical purpose during pregnancy and breastfeeding needs to be further characterized with proper pharmacokinetic studies in humans feasible in regions where cannabis has been legalized. Given the available data, significant transfer occurs to the fetus and the breastfed newborn with a theoretical risk of accumulation of products known to be biologically active.

Prediction of Carboxylesterase 1-mediated In Vivo Drug Interaction between Methylphenidate and Cannabinoids using Static and Physiologically Based Pharmacokinetic Models

The use of cannabis products has increased substantially. Cannabis products have been perceived and investigated as potential treatments for attention-deficit/hyperactivity disorder (ADHD). Accordingly, co-administration of cannabis products and methylphenidate (MPH), a first-line medication for ADHD, is possible. Oral MPH undergoes extensive presystemic metabolism by carboxylesterase 1 (CES1), a hepatic enzyme which can be inhibited by two prominent cannabinoids, Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD). This prompts further investigation into the likelihood of clinical interactions between MPH and these two cannabinoids through CES1 inhibition. In the present study, inhibition parameters were obtained from a human liver S9 system and then incorporated into static and physiologically-based pharmacokinetic (PBPK) models for prediction of potential clinical significance. The inhibition of MPH hydrolysis by THC and CBD was reversible, with estimated unbound inhibition constants (Ki,u) of 0.031 and 0.091 µM, respectively. The static model predicted a mild increase in MPH exposure by concurrent THC (34%) and CBD (94%) from smoking a cannabis cigarette and ingestion of prescriptive CBD, respectively. PBPK models suggested no significant interactions between single doses of MPH and CBD (2.5 - 10 mg/kg) when administered simultaneously, while a mild interaction (area under drug concentration-time curve increased by up to 55% and maximum concentration by up to 45%) is likely if multiple doses of CBD (10 mg/kg twice daily) are administered. In conclusion, the pharmacokinetic disposition of MPH can be potentially influenced by THC and CBD under certain clinical scenarios. Whether the magnitude of predicted interactions translates into clinically relevant outcomes requires verification in an appropriately designed clinical study. SIGNIFICANCE STATEMENT: This work demonstrated a potential mechanism of drug-drug interactions between methylphenidate (MPH) and two major cannabinoids (Δ9-tetrahydrocannabinol [THC] and cannabidiol [CBD]) not previously reported. We predicted a mild interaction between MPH and THC when the cannabinoid exposure occurred via cannabis smoking. Mild interactions between MPH and CBD were predicted with multiple oral administrations of CBD.

Cannabidiol and Cannabidiol Metabolites: Pharmacokinetics, Interaction with Food, and Influence on Liver Function

Cannabidiol (CBD) is widely available and marketed as having therapeutic properties. Over-the-counter CBD is unregulated, many of the therapeutic claims lack scientific support, and controversy exists as to the safety of CBD-liver interaction. The study aims were to compare the pharmacokinetics of commercial CBD and CBD metabolites following the ingestion of five different CBD formulations, determine the influence of CBD on food induced thermogenesis, determine the influence of food on CBD pharmacokinetics, and determine the influence of CBD on markers of liver function. Fourteen males (body mass index ≥ 25 kg/m²) were studied in a placebo-controlled, randomized, crossover design. On five occasions, different CBD formulations were ingested (one per visit). On two additional occasions, CBD or placebo was ingested following a meal. CBD servings were standardized to 30 mg. Considerable pharmacokinetic variability existed between formulations; this pharmacokinetic variability transferred to several of the metabolites. CBD did not influence food induced thermogenesis but did favorably modify early insulin and triglyceride responses. Food appreciably altered the pharmacokinetics of CBD. Finally, CBD did not evoke physiologically relevant changes in markers of liver function. Collectively, these data suggest that consumers should be aware of the appreciable pharmacokinetic differences between commercial CBD formulations, CBD is unlikely to influence the caloric cost of eating but may prove to be of some benefit to initial metabolic responses, consuming CBD with food alters the dynamics of CBD metabolism and increases systemic availability, and low-dose CBD probably does not represent a risk to normal liver function.

Pharmacokinetic Profile of ∆9-Tetrahydrocannabinol, Cannabidiol and Metabolites in Blood following Vaporization and Oral Ingestion of Cannabidiol Products

There is limited data on the comparative pharmacokinetics of cannabidiol (CBD) across oral and vaporized formulations. This within-subject, double-blind, double-dummy, placebo-controlled laboratory study analyzed the pharmacokinetic profile of CBD, ∆9-tetrahydrocannabinol (∆9-THC) and related metabolites in blood and oral fluid (OF) after participants (n = 18) administered 100 mg of CBD in each of the following formulations: (1) oral CBD, (2) vaporized CBD and (3) vaporized CBD-dominant cannabis containing 10.5% CBD and 0.39% ∆9-THC (3.7 mg); all participants also completed a placebo condition. Oral CBD was administered in three formulations: (1) encapsulated CBD, (2) CBD suspended in pharmacy-grade syrup and (3) Epidiolex, allowing for pharmacokinetic comparisons across oral formulations (n = 6 per condition). An optional fifth experimental condition was completed for six participants in which they fasted from all food for 12 h prior to oral ingestion of 100 mg of CBD. Blood and OF samples were collected immediately before and for 57-58 h after each drug administration. Immunoassay screening and LC-MS-MS confirmatory tests were performed, the limit of quantitation was 0.5 ng/mL for ∆9-THC and 1 ng/mL for CBD. The mean Cmax and range of CBD blood concentrations for each product were as follows: vaporized CBD-dominant cannabis, 171.1 ng/mL, 40.0-665.0 ng/mL, vaporized CBD 104.6 ng/mL, 19.0-312.0 ng/mL and oral CBD, 13.7 ng/mL, 0.0-50.0 ng/mL. Of the three oral formulations, Epidiolex produced the greatest peak concentration of CBD (20.5 ng/mL, 8.0-37.0 ng/mL) relative to the capsule (17.8 ng/mL, 2.0-50.0 ng/mL) and syrup (2.8 ng/mL, 0-7.0 ng/mL). ∆9-THC was detected in the blood of 12/18 participants after vaporized CBD-dominant cannabis use, but neither ∆9-THC nor its metabolite THC-COOH were detected in the blood of any participants after vaporized or oral CBD-only administration. These data demonstrate that different oral and vaporized formulations produce substantial variability in the pharmacokinetics of CBD and that CBD alone is unlikely to convert to ∆9-THC or produce positive drug tests for ∆9-THC or its metabolite.

A Phase 1 Open-Label, Fixed-Sequence Pharmacokinetic Drug Interaction Trial to Investigate the Effect of Cannabidiol on the CYP1A2 Probe Caffeine in Healthy Subjects

This pharmacokinetic (PK) drug‐interaction trial investigated the effects of repeated dosing of a plant‐derived pharmaceutical formulation of highly purified cannabidiol (CBD; Epidiolex in the United States and Epidyolex in Europe; 100 mg/mL oral solution) on caffeine clearance via modulation of cytochrome P450 (CYP) 1A2 activity in healthy adults. In this phase 1 open‐label, fixed‐sequence trial, all subjects received a single 200 mg caffeine dose and placebo on day 1. Subjects then titrated CBD from 250 mg once daily to 750 mg twice daily between days 3 and 11 and took 750 mg CBD twice daily between days 12 and 27. On day 26, subjects received a single 200‐mg caffeine dose with their morning CBD dose. Plasma concentrations of caffeine and its CYP1A2‐mediated metabolite, paraxanthine, were determined on days 1 and 26 and PK parameters derived using noncompartmental analysis. Safety was monitored throughout. Sixteen subjects enrolled, and 9 completed treatment. When caffeine was administered with steady‐state CBD, caffeine exposure increased by 15% for C_max and 95% for AUC_0‐∞, t_max increased from 1.5 to 3.0 hours, and t_1/2 increased from 5.4 to 10.9 hours compared with caffeine administered with placebo. Under the same conditions, paraxanthine exposure decreased by 22% for C_max and increased by 18% for AUC_0‐∞, t_max increased from 8.0 to 14.0 hours, and t_1/2 increased from 7.2 to 13.7 hours. Overall, there were no unexpected adverse events; diarrhea was most common, and 6 subjects discontinued because of elevated liver transaminases. These data suggest that CBD is an inhibitor of CYP1A2.

Time to onset of cannabidiol (CBD) treatment effect in Lennox-Gastaut syndrome: Analysis from two randomized controlled trials

OBJECTIVE

To estimate time to onset of cannabidiol (CBD) treatment effect (seizure reduction and adverse events [AEs]), we conducted post hoc analyses of data from two randomized, placebo-controlled, Phase 3 trials, GWPCARE3 (NCT02224560) and GWPCARE4 (NCT02224690), of patients with Lennox-Gastaut syndrome.

METHODS

Patients received plant-derived pharmaceutical formulation of highly purified CBD (Epidiolex, 100 mg/ml oral solution) at 10 mg/kg/day (CBD10; GWPCARE3) or 20 mg/kg/day (CBD20; both trials) or placebo for 14 weeks. Treatment started at 2.5 mg/kg/day for all groups and reached 10 mg/kg/day on Day 7 and 20 mg/kg/day (CBD20 and matching placebo only) on Day 11. Percentage change from baseline in drop seizure frequency was calculated by cumulative day (i.e., including all previous days). Time to onset and resolution of AEs were evaluated.

RESULTS

Overall, 235 patients received CBD (CBD10 [GWPCARE3 only], n = 67; CBD20 [pooled GWPCARE3&4], n = 168) and 161 received placebo. Mean (range) age was 15.3 years (2.6-48.0). Patients had previously discontinued a median (range) of six (0-28) antiepileptic drugs (AEDs) and were currently taking a median of three (0-5) AEDs. Differences in drop seizure reduction between placebo and CBD emerged during the titration period and became nominally significant by Day 6 (p = .008) for pooled CBD treatment groups. Separation between placebo and CBD in ≥50% responder rate emerged by Day 6. Onset of the first reported AE occurred during the titration period in 45% of patients (CBD10, 46%; CBD20, 52%; placebo, 38%). In patients with AEs, resolution occurred within 4 weeks of onset in 53% of placebo and 39% of CBD patients and by end of study in 63% of placebo and 61% of CBD patients.

SIGNIFICANCE

Treatment effect (efficacy and AEs) of CBD may occur within 1 week of starting treatment. Although AEs lasted longer for CBD than placebo, most resolved within the 14-week period.

Pharmacokinetics and effects on arachidonic acid metabolism of low doses of cannabidiol following oral administration to horses

The increasing availability of cannabidiol (CBD) and anecdotal reports of its anti-inflammatory effects has garnered it much interest in the equine industry. The objectives of the current study were to (1) describe the pharmacokinetics of oral CBD in exercising thoroughbreds, (2) characterize select behavioral and physiologic effects, and (3) evaluate effects on biomarkers of inflammation using an ex vivo model. This study was conducted in a randomized balanced 3-way crossover design with a two-week washout period between doses. Horses received a single oral dose (0.5, 1, and 2 mg/kg) of CBD suspended in sesame oil. Blood and urine samples were collected prior to and for 72 hr post drug administration. Additional blood samples collected at select time points were challenged ex vivo with calcium ionophore or lipopolysaccharide to induce eicosanoid production. Drug, metabolite, and eicosanoid concentrations were determined using LC-MS/MS. Cannabidiol was well tolerated with no significant behavioral, gastrointestinal, or cardiac abnormalities observed. CBD was readily absorbed, with parent drug detected in blood at all time points. The carboxylated and hydroxylated metabolites predominated in serum and urine, respectively. The terminal half-life for CBD was 10.7 ± 3.61, 10.6 ± 3.84 and 9.88 ± 3.53 for 0.5, 1, and 2 mg/kg. Although the effects were mixed, results of eicosanoid analysis suggest CBD affects COX-1, COX-2 and LOX at the doses studied here. Results of this study coupled with previous reports in other species, suggest further study of CBD in horses is warranted before its use as an anti-inflammatory can be recommended.

Safety, Pharmacokinetics, and Pharmacodynamics of Spectrum Yellow Oil in Healthy Participants

Due to a lack of published pharmacokinetic (PK) and/or pharmacodynamic (PD) data, decision-making surrounding appropriate dosing of cannabis used for medical purposes is limited. This multiple-dose study evaluated the safety, tolerability, PK, and PD of Spectrum Yellow oil [20 mg/mL cannabidiol (CBD)/<1 mg/mL ∆9-tetrahydrocannabinol (THC)]. Participants (N=43) were randomized to one of five groups: 120 mg CBD and 5.4 mg THC daily, 240 mg CBD and 10.8 mg THC daily, 360 mg CBD and 16.2 mg THC daily, 480 mg CBD and 21.6 mg THC daily, or placebo. Study medication was administered every 12 hours for seven consecutive days. Treatment-emergent adverse events (TEAEs); plasma and urine concentrations of THC, CBD, and metabolites; and self-reported subjective effects were collected. Nearly all TEAEs (44/45) were of mild or moderate severity; none was serious. The highest incidence of TEAEs (67%) was in the two higher-dose treatment groups. The highest number of TEAEs (17/45) occurred on the first treatment day. Steady-state plasma CBD concentrations were reached by Day 7. On Day 7, CBD exposure showed dose-proportionality (AUC0-t slope=1.03 [0.70, 1.36], Cmax slope=0.92 [0.53, 1.31]). Most plasma THC concentrations were below the limit of quantification. Across Days 1 and 7, there were no consistent differences in subjective effects between placebo and active study medication. A prudent approach to improve tolerability with Spectrum Yellow oil might involve initial doses no higher than 240 mg total CBD and 10.8 mg total THC daily in divided doses, with titration upwards over time as needed based on tolerability.

Cannabidiol in Pharmacoresistant Epilepsy: Clinical Pharmacokinetic Data From an Expanded Access Program

Background and Aim: Data on the clinical pharmacokinetics of cannabidiol (CBD) are scanty. We explored the effect of demographic and clinical variables on plasma concentrations of purified CBD in patients with Dravet (DS) and Lennox–Gastaut syndrome (LGS).

Methods: The study design was an open, prospective, multicenter expanded access program (EAP). Venous blood samples were drawn from patients between 8 and 9 am, before the CBD morning dose, 12 h apart from the last evening dose, and then 2.5 h after their usual morning dose.

Results: We collected 127 plasma samples (67-morning pre-dosing and 60 post-dosing) from 43 patients (24 females, 19 males), 27 with LGS and 16 with DS. Mean ± standard deviation age was 26 ± 15 years. Duration of CBD treatment averaged 4.2 ± 2.9 months at 13.2 ± 4.6 mg/kg/day. CBD median trough plasma concentration was 91 ng/ml; it doubled to 190 ng/ml 2.5 h post-dosing (p < 0.001). Cannabidiol trough plasma concentrations were linearly related to daily doses (r = 0.564, p < 0.001). Median trough CBD plasma concentration-to-weight-adjusted dose ratio (C/D) was 32% higher (p < 0.02) in plasma samples from subjects aged 18 and over than in those under 18. Sex and concomitant antiseizure medications (ASMs) were not associated with significant variations in CBD C/D, but caution is required due to the potential influence of confounders.

Conclusion: These are the first data on CBD pharmacokinetics in children and adults with LGS or DS in a real-world setting. The most relevant finding was the higher CBD C/D in adults. In practice, reduced weight-normalized doses might be required with aging to achieve the same CBD plasma levels.

Cannabidiol in the treatment of epilepsy: Current evidence and perspectives for further research

The therapeutic potential of cannabidiol (CBD) in seizure disorders has been known for many years, but it is only in the last decade that major progress has been made in characterizing its preclinical and clinical properties as an antiseizure medication. The mechanisms responsible for protection against seizures are not fully understood, but they are likely to be multifactorial and to include, among others, antagonism of G protein-coupled receptor, desensitization of transient receptor potential vanilloid type 1 channels, potentiation of adenosine-mediated signaling, and enhancement of GABAergic transmission. CBD has a low and highly variable oral bioavailability, and can be a victim and perpetrator of many drug-drug interactions. A pharmaceutical-grade formulation of purified CBD derived from Cannabis sativa has been evaluated in several randomized placebo-controlled adjunctive-therapy trials, which resulted in its regulatory approval for the treatment of seizures associated with Dravet syndrome, Lennox-Gastaut syndrome and tuberous sclerosis complex. Interpretation of results of these trials, however, has been complicated by the occurrence of an interaction with clobazam, which leads to a prominent increase in the plasma concentration of the active metabolite N-desmethylclobazam in CBD-treated patients. Despite impressive advances, significant gaps in knowledge still remain. Areas that require further investigation include the mechanisms underlying the antiseizure activity of CBD in different syndromes, its pharmacokinetic profile in infants and children, potential relationships between plasma drug concentration and clinical response, interactions with other co-administered medications, potential efficacy in other epilepsy syndromes, and magnitude of antiseizure effects independent from interactions with clobazam. This article is part of the special issue on 'Cannabinoids'.

Comparison of Five Oral Cannabidiol Preparations in Adult Humans: Pharmacokinetics, Body Composition, and Heart Rate Variability

Data supporting the physiological effects of cannabidiol (CBD) ingestion in humans are conflicting. Differences between CBD preparations and bioavailability may contribute to these discrepancies. Further, an influence of body composition on CBD bioavailability is feasible, but currently undocumented. The aims of this study were to: (1) compare the pharmacokinetics of five oral CBD preparations over 4 h; (2) examine the relationship between body composition and CBD pharmacokinetics; and, (3) explore the influence of CBD on heart rate variability. In total, five preparations of CBD, standardized to 30 mg, were orally administered to 15 healthy men and women (21-62 years) in a randomized, crossover design. Prior to and 60 min following CBD ingestion, heart rate variability was determined. Body composition was assessed using dual energy X-ray absorptiometry. Peak circulating CBD concentration, time to peak concentration, and area under the curve was superior in a preparation comprising 5% CBD concentration liquid. Fat free mass was a significant predictor (R ² = 0.365, p = 0.017) of time to peak concentration for this preparation. Several heart rate variability parameters, including peak frequency of the high frequency band, were favorably, but modestly modified following CBD ingestion. These data confirm an influence of CBD preparation and body composition on CBD bioavailability, and suggest that acute CBD ingestion may have a modest influence on autonomic regulation of heart rate.

Pharmacokinetics of cannabidiol in children with refractory epileptic encephalopathy

Growing interest in the clinical use of cannabidiol (CBD) as adjuvant therapy for pediatric refractory epileptic encephalopathy emphasizes the need for drug treatment optimization. The aim of this study was to characterize the pharmacokinetics of CBD in pediatric patients with refractory epileptic encephalopathy receiving an oil-based oral solution. To evaluate CBD concentrations, six serial blood samples per patient were collected after the morning dose of CBD, at least 21 days after the beginning of treatment. Twelve patients who received a median (range) dose of 12.2 (5.3-19.4) mg/kg/d (twice daily) were included in the analysis. Median (range) CBD time to maximum plasma concentration, maximum plasma concentration, and area under the concentration versus time curve up to 6 hours after dosing were 3.2 hours (1.9-6.2), 49.6 ng/mL (14.4-302.0), and 226.3 ng ⋅ h/mL (70.5-861.3), respectively. CBD systemic exposure parameters were in the lower range of previous reports in pediatric patients receiving doses in a similar range. Most of our patients (83%) showed little CBD plasma level fluctuation during a dosing interval, comparable to that encountered after oral administration of an extended release drug delivery system. CDB administration was generally safe and well tolerated, and a novel levothyroxine-CBD interaction was recorded. Similar to other studies, large interindividual variability in CBD exposure was observed, encouraging the use of CBD therapeutic drug monitoring.

A phase I trial of the safety, tolerability and pharmacokinetics of cannabidiol administered as single-dose oil solution and single and multiple doses of a sublingual wafer in healthy volunteers

AIMS

This study investigated the safety, tolerability and pharmacokinetics after administration of a specific Cannabis sativa cultivar extract, standardised to cannabidiol (CBD) content as sublingual wafer or oil formulation compared to nabiximols oromucosal spray.

METHODS

For the single-dose study, the design was an open-label, 4-way crossover in 12 healthy volunteers randomised to receive a sequence of 4 different single doses of CBD as a sublingual wafer (25 or 50 mg CBD), oil solution (50 mg CBD), or nabiximols oromucosal spray (20 mg CBD, 21.6 mg tetrahydrocannabinol). For the multiple-dose study, sublingual wafer (50 mg CBD) was administered twice a day for 5 days.

RESULTS

The extract was generally well tolerated by participants when administered in either wafer or oil form, with some adverse events, including mild or moderate somnolence, sedation and altered mood. The relative bioavailability of CBD after administration as a sublingual wafer was comparable with that of oil solution with 90% confidence interval of 83-131%. The median maximum concentrations of CBD after administration of oil solution and wafer was 9.4 and 11.9 ng mL^-1 , respectively. Maximum concentrations of CBD occurred 4 hours after administration, with an estimated terminal elimination half-life of 6 hours. There was no statistically significant difference between the AUC_0-τ of CBD after administration of oil solution or wafer compared with nabiximols oromucosal spray.

CONCLUSION

Oil solution and sublingual wafer formulations of the extract standardised with CBD were well tolerated and achieved equivalent concentrations of CBD when compared to an available commercial nabiximols formulation.

Practical use of pharmaceutically purified oral cannabidiol in Dravet syndrome and Lennox-Gastaut syndrome

INTRODUCTION

Pharmaceutically purified oral cannabidiol (CBD) has been recently approved by the US Food and Drug Administration and European Medicines Agency as treatment of seizures associated with Dravet syndrome (DS) and Lennox-Gastaut syndrome (LGS), which are severe and difficult-to-treat developmental and epileptic encephalopathies with onset in early childhood.

AREAS COVERED

This review will critically review the pharmacokinetic properties of CBD, the interactions with antiseizure and non-antiseizure medications, and the main tolerability and safety issues to provide guidance for its use in everyday practice.

EXPERT OPINION

CBD is metabolized in the liver and can influence the activity of enzymes involved in drug metabolism. The best characterized drug-drug interaction is between CBD and clobazam. The most common adverse events include somnolence, gastrointestinal discomfort, and increase in serum transaminases. High-grade purified CBD oral solution represents an effective therapeutic option in patients with DS and LGS. The findings cannot be extrapolated to other cannabis-based products, synthetic cannabinoids for medicinal use and non-medicinal cannabis and CBD derivatives.

Critical Aspects Affecting Cannabidiol Oral Bioavailability and Metabolic Elimination, and Related Clinical Implications

This article provides a critical appraisal of the available evidence concerning clinical exposure to orally administered cannabidiol (CBD), with special reference to factors affecting gastrointestinal absorption, presystemic elimination, and susceptibility to metabolic drug interactions. Although detailed studies have not been published, the available data suggest that the absolute bioavailability of CBD after oral dosing under fasting conditions is approximately 6%, and increases fourfold when the medication is co-administered with a high-fat meal. Based on measurements of CBD plasma exposure after oral dosing and a 6% absolute oral bioavailability estimate, the actual clearance of CBD in adults can be inferred to be in the order of 67 L/h, which is similar to the value of 74 ± 14 L/h (mean ± standard deviation) determined after intravenous injection of a 20-mg dose of deuterium-labeled CBD in five healthy subjects. Assuming that the CBD blood-to-plasma ratio is about 1, as in the case of tetrahydrocannabinol (THC), and that CBD metabolism takes place virtually entirely in the liver, it can be estimated that about 70 to 75% of an orally absorbed dose of CBD can be removed by hepatic metabolism before reaching the systemic circulation, and additionally CBD gastrointestinal absorption is incomplete. A formulation with improved biopharmaceutical properties could increase the extent of CBD absorption about fourfold (i.e., to the level achieved with the currently available formulations co-administered with a high-fat meal) and minimize the influence of food effects on CBD bioavailability. There is also potential for favoring the absorption of CBD through the enteric lymphatic system, thereby reducing the extent of presystemic hepatic elimination. Evidence that CBD can behave as a high hepatic clearance compound also has implications when predicting the magnitude of drug-drug interactions affecting CBD metabolism. These considerations have important clinical relevance, particularly with respect to the objective of minimizing pharmacokinetic variability and consequent intra- and interindividual differences in therapeutic response and susceptibility to adverse effects.

A phase 1, randomized, pharmacokinetic trial of the effect of different meal compositions, whole milk, and alcohol on cannabidiol exposure and safety in healthy subjects

OBJECTIVE

The pharmacokinetics (PK) and safety of single oral 750-mg doses of a plant-derived pharmaceutical formulation of highly purified cannabidiol (CBD; Epidiolex in the USA and Epidyolex in Europe; 100-mg/mL oral solution) were assessed in healthy adults following a high-fat/calorie meal (n = 15), a low-fat/calorie meal (n = 14), whole milk (n = 15), or alcohol (n = 14), relative to the fasted state (n = 29).

METHODS

Blood samples were collected until 96 hours postdose in each period and evaluated by liquid chromatography and tandem mass spectrometry. PK parameters (maximum observed plasma concentration [C_max ], area under the plasma concentration-time curve from time zero to the last observed quantifiable concentration, area under the concentration-time curve from time zero to infinity [AUC_0-∞ ], and time to maximum plasma concentration [t_max ]) of CBD and its major metabolites were derived using noncompartmental analysis.

RESULTS

CBD exposure increased by 3.8-fold for AUC_0-∞ and 5.2-fold for C_max when CBD was administered with a high-fat/calorie meal versus fasted. To a lesser extent, a low-fat/calorie meal enhanced CBD exposure versus fasted with a 2.7-fold increase in AUC_0-∞ and a 3.8-fold increase in C_max . Similarly, when dosed with whole milk, CBD exposure increased versus fasted by 2.4-fold for AUC_0-∞ and 3.1-fold for C_max . Modest elevations in CBD exposure occurred when it was dosed with alcohol: 1.6-fold for AUC_0-∞ and 1.9-fold for C_max . No clinically relevant effect of any test condition on CBD t_max or t_½ versus the fasted state was apparent. The same trend was seen for the CBD metabolites, except that 7-carboxy-cannabidiol t_max was considerably longer when CBD was administered with alcohol (14 vs 4 hours fasted). Inter- and intrasubject variability in PK parameters was moderate to high during the trial.

SIGNIFICANCE

CBD and metabolite exposures were most affected by a high-fat/calorie meal. CBD exposures also increased with a low-fat/calorie meal, whole milk, or alcohol, but to a lesser extent. CBD was tolerated, and there were no severe or serious adverse events during the trial.

CBD Effects on TRPV1 Signaling Pathways in Cultured DRG Neurons

INTRODUCTION

Cannabidiol (CBD) is reported to produce pain relief, but the clinically relevant cellular and molecular mechanisms remain uncertain. The TRPV1 receptor integrates noxious stimuli and plays a key role in pain signaling. Hence, we conducted in vitro studies, to elucidate the efficacy and mechanisms of CBD for inhibiting neuronal hypersensitivity in cultured rat sensory neurons, following activation of TRPV1.

METHODS

Adult rat dorsal root ganglion (DRG) neurons were cultured and supplemented with the neurotrophic factors NGF and GDNF, in an established model of neuronal hypersensitivity. Neurons were stimulated with CBD (Adven 150, EMMAC Life Sciences) at 1, 10, 100 nMol/L and 1, 10 and 50 µMol/L, 48 h after plating. In separate experiments, DRG neurons were also stimulated with capsaicin with or without CBD (1 nMol/L to10 µMol/L), in a functional calcium imaging assay. The effects of the adenylyl cyclase activator forskolin and the calcineurin inhibitor cyclosporin were determined. We also measured forskolin-stimulated cAMP levels, without and after treatment with CBD, using a homogenous time-resolved fluorescence (HTRF) assay. The results were analysed using Mann-Whitney test.

RESULTS

DRG neurons treated with 10 and 50 µMol/L CBD showed calcium influx, but not at lower doses. Neurons treated with capsaicin demonstrated robust calcium influx, which was dose-dependently reduced in the presence of low dose CBD (IC₅₀ = 100 nMol/L). The inhibition or desensitization by CBD was reversed in the presence of forskolin and cyclosporin. Forskolin-stimulated cAMP levels were significantly reduced in CBD treated neurons.

CONCLUSION

CBD at low doses corresponding to plasma concentrations observed physiologically inhibits or desensitizes neuronal TRPV1 signalling by inhibiting the adenylyl cyclase - cAMP pathway, which is essential for maintaining TRPV1 phosphorylation and sensitization. CBD also facilitated calcineurin-mediated TRPV1 inhibition. These mechanisms may underlie nociceptor desensitization and the therapeutic effect of CBD in animal models and patients with acute and chronic pain.