Serum cannabidiol, tetrahydrocannabinol (THC), and their native acid derivatives after transdermal application of a low-THC Cannabis sativa extract in beagles.

Cannabinoids hold promise for treating health problems related to inflammation and chronic pain in dogs, in particular cannabidiol (CBD), and its native acid derivative cannabidiolic acid (CBDA). Information regarding systemic delivery of cannabinoids through transdermal routes is sparse. The purpose of this study was to determine pharmacokinetics of transdermal administration of a low-THC Cannabis sativa extract in healthy dogs. Six purpose-bred research beagles were treated with a transdermal CBD-CBDA-rich extract, and serum concentrations of CBD, CBDA, tetrahydrocannabinol (THC), and its acid derivative tetrahydrocannabinolic acid (THCA) were examined prior to and at the end of weeks 1 and 2. A 4 mg/kg dose of total cannabinoids twice daily resulted in appx 10 ng/ml of CBD, 21-32 ng/ml of CBDA, trace amounts of THCA, and unquantifiable amounts of THC in serum at the end of weeks 1 and 2 of treatment. Results showed that CBDA and THCA were absorbed better systemically than CBD or THC.

Association of Naturalistic Administration of Cannabis Flower and Concentrates With Intoxication and Impairment.

Importance: The rapidly growing legal cannabis market includes new and highly potent products, the effects of which, to our knowledge, have not previously been examined in biobehavioral research studies because of federal restrictions on cannabis research. Objective: To use federally compatible, observational methods to study high-∆9-tetrahydrocannabinol (THC) legal market forms of cannabis. Design, Setting, and Participants: In this cohort study with a between-groups design that was conducted in a community and university setting, cannabis flower users and concentrate users were randomly assigned to higher- vs lower-THC products within user groups. Participants completed a baseline and an experimental mobile laboratory assessment that included 3 points: before, immediately after, and 1 hour after ad libitum legal market flower and concentrate use. Of the 133 individuals enrolled and assessed, 55 regular flower cannabis users (41.4%) and 66 regular concentrate cannabis users (49.6%) complied with the study's cannabis use instructions and had complete data across primary outcomes. Exposures: Flower users were randomly assigned to use either 16% or 24% THC flower and concentrate users were randomly assigned to use either 70% or 90% THC concentrate that they purchased from a dispensary. Main Outcomes and Measures: Primary outcome measures included plasma cannabinoids, subjective drug intoxication, and neurobehavioral tasks testing attention, memory, inhibitory control, and balance. Results: A total of 121 participants completed the study for analysis: 55 flower users (mean [SD] age, 28.8 [8.1] years; 25 women [46%]) and 66 concentrate users (mean [SD] age, 28.3 [10.4] years; 30 women [45%]). Concentrate users compared with flower users exhibited higher plasma THC levels and 11-hydroxyΔ9-THC (THC's active metabolite) across all points. After ad libitum cannabis administration, mean plasma THC levels were 0.32 (SE = 0.43) µg/mL in concentrate users (to convert to millimoles per liter, multiply by 3.18) and 0.14 (SE = 0.16) µg/mL in flower users. Most neurobehavioral measures were not altered by short-term cannabis consumption. However, delayed verbal memory (F1,203 = 32.31; P < .001) and balance function (F1,203 = 18.88; P < .001) were impaired after use. Differing outcomes for the type of product (flower vs concentrate) or potency within products were not observed. Conclusions and Relevance: This study provides information about the association of pharmacological and neurobehavioral outcomes with legal market cannabis. Short-term use of concentrates was associated with higher levels of THC exposure. Across forms of cannabis and potencies, users' domains of verbal memory and proprioception-focused postural stability were primarily associated with THC administration.

Pharmacokinetics of Sativex® in Dogs: Towards a Potential Cannabinoid-Based Therapy for Canine Disorders.

The phytocannabinoid-based medicine Sativex® is currently marketed for the treatment of spasticity and pain in multiple sclerosis patients and is being investigated for other central and peripheral pathological conditions. It may also serve in Veterinary Medicine for the treatment of domestic animals, in particular for dogs affected by different pathologies, including human-like pathological conditions. With the purpose of assessing different dosing paradigms for using Sativex in Veterinary Medicine, we investigated its pharmacokinetics when administered to naïve dogs via sublingual delivery. In the single dose arm of the study, adult Beagle dogs were treated with 3 consecutive sprays of Sativex, and blood samples were collected at 12 intervals up to 24 h later. In the multiple dose arm of the study, Beagle dogs received 3 sprays daily for 14 days, and blood samples were collected for 24 h post final dose. Blood was used to obtain plasma samples and to determine the levels of cannabidiol (CBD), Δ9-tetrahydrocannabinol (Δ9-THC) and its metabolite 11-hydroxy-Δ9-THC. Maximal plasma concentrations of both Δ9-THC (Cmax = 18.5 ng/mL) and CBD (Cmax = 10.5 ng/mL) were achieved 2 h after administration in the single dose condition and at 1 h in the multiple dose treatment (Δ9-THC: Cmax = 24.5 ng/mL; CBD: Cmax = 15.2 ng/mL). 11hydroxy-Δ9-THC, which is mainly formed in the liver from Δ9-THC, was almost undetected, which is consistent with the use of sublingual delivery. A potential progressive accumulation of both CBD and Δ9-THC was detected following repeated exposure, with maximum plasma concentrations for both cannabinoids being achieved following multiple dose. Neurological status, body temperature, respiratory rate and some hemodynamic parameters were also recorded in both conditions, but in general, no changes were observed. In conclusion, this study demonstrates that single or multiple dose sublingual administration of Sativex to naïve dogs results in the expected pharmacokinetic profile, with maximal levels of phytocannabinoids detected at 1-2 h and suggested progressive accumulation after the multiple dose treatment.

Heavy Cannabis Use Associated With Reduction in Activated and Inflammatory Immune Cell Frequencies in Antiretroviral Therapy-Treated Human Immunodeficiency Virus-Infected Individuals.

Background: Cannabis is a widely used drug in the United States, and the frequency of cannabis use in the human immunodeficiency virus (HIV)-infected population is disproportionately high. Previous human and macaque studies suggest that cannabis may have an impact on plasma viral load; however, the relationship between cannabis use and HIV-associated systemic inflammation and immune activation has not been well defined. Methods: The impact of cannabis use on peripheral immune cell frequency, activation, and function was assessed in 198 HIV-infected, antiretroviral-treated individuals by flow cytometry. Individuals were categorized into heavy, medium, or occasional cannabis users or noncannabis users based on the amount of the cannabis metabolite 11-nor-carboxy-tetrahydrocannabinol (THC-COOH) detected in plasma by mass spectrometry. Results: Heavy cannabis users had decreased frequencies of human leukocyte antigen (HLA)-DR+CD38+CD4+ and CD8+ T-cell frequencies, compared to frequencies of these cells in non-cannabis-using individuals. Heavy cannabis users had decreased frequencies of intermediate and nonclassical monocyte subsets, as well as decreased frequencies of interleukin 23- and tumor necrosis factor-α-producing antigen-presenting cells. Conclusions: While the clinical implications are unclear, our findings suggest that cannabis use is associated with a potentially beneficial reduction in systemic inflammation and immune activation in the context of antiretroviral-treated HIV infection.

Cannabinoid Disposition After Human Intraperitoneal Use: AnInsight Into Intraperitoneal Pharmacokinetic Properties in Metastatic Cancer.

BACKGROUND: Medicinal cannabis is prescribed under the provision of a controlled drug in the Australian Poisons Standard. However, multiple laws must be navigated in order for patients to obtain access and imported products can be expensive. Dose-response information for both efficacy and toxicity pertaining to medicinal cannabis is lacking. The pharmacokinetic properties of cannabis administered by traditional routes has been described but to date, there is no literature on the pharmacokinetic properties of an intraperitoneal cannabinoid emulsion. CASE DESCRIPTION: A cachectic 56-year-old female with stage IV ovarian cancer and peritoneal metastases presented to hospital with fevers, abdominal distension and severe pain, vomiting, anorexia, dehydration and confusion. The patient reported receiving an intraperitoneal injection, purported to contain 12g of mixed cannabinoid (administered by a deregistered medical practitioner) two days prior to presentation. Additionally, cannabis oil oral capsules were administered in the hours prior to hospital admission. RESULTS: THC concentrations were consistent with the clinical state but not with the known pharmacokinetic properties of cannabis nor of intraperitoneal absorption. THC concentrations at the time of presentation were predicted to be ~60ng/mL. Evidence suggests that blood THC concentrations >5ng/mL are associated with substantial cognitive and psychomotor impairment. The predicted time for concentrations to drop <5ng/mL was 49days after administration. DISCUSSION: The unusual pharmacokinetic properties of the case suggest that there is a large amount unknown about cannabis pharmacokinetic properties. The pharmacokinetic properties of a large amount of a lipid soluble compound given intraperitoneally gave insights into the absorption and distribution of cannabinoids, particularly in the setting of metastatic malignancy.

Δ9-THC Disrupts Gamma (γ)-Band Neural Oscillations in Humans.

Gamma (γ)-band oscillations play a key role in perception, associative learning, and conscious awareness and have been shown to be disrupted by cannabinoids in animal studies. The goal of this study was to determine whether cannabinoids disrupt γ-oscillations in humans and whether these effects relate to their psychosis-relevant behavioral effects. The acute, dose-related effects of Δ-9-tetrahydrocannabinol (Δ(9)-THC) on the auditory steady-state response (ASSR) were studied in humans (n=20) who completed 3 test days during which they received intravenous Δ(9)-THC (placebo, 0.015, and 0.03 mg/kg) in a double-blind, randomized, crossover, and counterbalanced design. Electroencephalography (EEG) was recorded while subjects listened to auditory click trains presented at 20, 30, and 40 Hz. Psychosis-relevant effects were measured with the Positive and Negative Syndrome scale (PANSS). Δ(9)-THC (0.03 mg/kg) reduced intertrial coherence (ITC) in the 40 Hz condition compared with 0.015 mg/kg and placebo. No significant effects were detected for 30 and 20 Hz stimulation. Furthermore, there was a negative correlation between 40 Hz ITC and PANSS subscales and total scores under the influence of Δ(9)-THC. Δ(9)-THC (0.03 mg/kg) reduced evoked power during 40 Hz stimulation at a trend level. Recent users of cannabis showed blunted Δ(9)-THC effects on ITC and evoked power. We show for the first time in humans that cannabinoids disrupt γ-band neural oscillations. Furthermore, there is a relationship between disruption of γ-band neural oscillations and psychosis-relevant phenomena induced by cannabinoids. These findings add to a growing literature suggesting some overlap between the acute effects of cannabinoids and the behavioral and psychophysiological alterations observed in psychotic disorders.

The pharmacokinetics, efficacy, safety, and ease of use of a novel portable metered-dose cannabis inhaler in patients with chronic neuropathic pain: a phase 1a study.

Chronic neuropathic pain is often refractory to standard pharmacological treatments. Although growing evidence supports the use of inhaled cannabis for neuropathic pain, the lack of standard inhaled dosing plays a major obstacle in cannabis becoming a "main stream" pharmacological treatment for neuropathic pain. The objective of this study was to explore the pharmacokinetics, safety, tolerability, efficacy, and ease of use of a novel portable thermal-metered-dose inhaler (tMDI) for cannabis in a cohort of eight patients suffering from chronic neuropathic pain and on a stable analgesic regimen including medicinal cannabis. In a single-dose, open-label study, patients inhaled a single 15.1 ± 0.1 mg dose of cannabis using the Syqe Inhaler device. Blood samples for Δ(9)-tetrahydrocannabinol (THC) and 11-hydroxy-Δ(9)-THC were taken at baseline and up to 120 minutes. Pain intensity (0-10 VAS), adverse events, and satisfaction score were monitored following the inhalation. A uniform pharmacokinetic profile was exhibited across all participants (Δ(9)-THC plasma Cmax ± SD was 38 ± 10 ng/mL, Tmax ± SD was 3 ± 1 minutes, AUC0→infinity ± SD was 607 ± 200 ng·min/mL). Higher plasma Cmax increase per mg Δ(9)-THC administered (12.3 ng/mL/mg THC) and lower interindividual variability of Cmax (25.3%), compared with reported alternative modes of THC delivery, were measured. A significant 45% reduction in pain intensity was noted 20 minutes post inhalation (P = .001), turning back to baseline within 90 minutes. Tolerable, lightheadedness, lasting 15-30 minutes and requiring no intervention, was the only reported adverse event. This trial suggests the potential use of the Syqe Inhaler device as a smokeless delivery system of medicinal cannabis, producing a Δ(9)-THC pharmacokinetic profile with low interindividual variation of Cmax, achieving pharmaceutical standards for inhaled drugs.

Plasma cannabinoid concentrations during dronabinol pharmacotherapy for cannabis dependence.

BACKGROUND: Recently, high-dose oral synthetic delta-9-tetrahydrocannabinol (THC) was shown to alleviate cannabis withdrawal symptoms. The present data describe cannabinoid pharmacokinetics in chronic, daily cannabis smokers who received high-dose oral THC pharmacotherapy and later a smoked cannabis challenge. METHODS: Eleven daily cannabis smokers received 0, 30, 60, or 120 mg/d THC for four 5-day medication sessions, each separated by 9 days of ad libitum cannabis smoking. On the fifth day, participants were challenged with smoking one 5.9% THC cigarette. Plasma collected on the first and fifth days was quantified by two-dimensional gas chromatography mass spectrometer for THC, 11-hydroxy-THC (11-OH-THC), and 11-nor-9-carboxy-THC (THCCOOH). Linear ranges (ng/mL) were 0.5-100 for THC, 1-50 for 11-OH-THC, and 0.5-200 for THCCOOH. RESULTS: During placebo dosing, THC, 11-OH-THC, and THCCOOH concentrations consistently decreased, whereas all cannabinoids increased dose dependently during active dronabinol administration. THC increase over time was not significant after any dose, 11-OH-THC increased significantly during the 60- and 120-mg/d doses, and THCCOOH increased significantly only during the 120-mg/d dose. THC, 11-OH-THC, and THCCOOH concentrations peaked within 0.25 hours after cannabis smoking, except after 120 mg/d THC when THCCOOH peaked 0.5 hours before smoking. CONCLUSIONS: The significant withdrawal effects noted during placebo dronabinol administration were supported by significant plasma THC and 11-OH-THC concentration decreases. During active dronabinol dosing, significant dose-dependent increases in THC and 11-OH-THC concentrations support withdrawal symptom suppression. THC concentrations after cannabis smoking were only distinguishable from oral THC doses for 1 hour, too short a period to feasibly identify cannabis relapse. THCCOOH/THC ratios were higher 14 hours after overnight oral dronabinol abstinence but cannot distinguish oral THC dosing from the smoked cannabis intake.

[Does a positive finding of tetrahydrocannabinol in the blood result from ingestion of Indian frankincense (Boswellia serrata)?]. / Führt die Einnahme von indischem Weihrauch zu einem positiven Tetrahydrocannabinolbefund im Blut?

The exculpatory statement that a positive THC finding in the blood is due to the consumption of hemp products or passive exposure to cannabis smoke has been disproved by the monitoring of hemp products and recent passive inhalation studies conducted in social settings, which showed that these conditions are unlikely to produce a positive result in the blood. The defense that the ingestion of Indian olibanum may result in a positive THC concentration in the blood is unusual; it is based on older publications where authors had speculated on a possible association of the synthetic pathways of THC from terpenoid precursors also being present in olibanum and the biogenesis of THC in hemp. It had further been speculated whether chemical or plant-derived pathways may also occur in humans. A thorough understanding of the different pathways and recently published results have outdated these speculations.

Does olanzapine inhibit the psychomimetic effects of Δ9-tetrahydrocannabinol?

Δ9-Tetrahydrocannabinol (THC) produces transient psychomimetic effects in healthy volunteers, constituting a pharmacological model for psychosis. The dopaminergic antagonist haloperidol has previously been shown to reduce these effects. This placebo-controlled, cross-over study in 49 healthy, male, mild cannabis users aimed to further explore this model by examining the effect of a single oral dose of olanzapine (with dopaminergic, serotonergic, adrenergic, muscarinergic and histaminergic properties) or two oral doses of diphenhydramine (histamine antagonist) on the effects of intrapulmonarily administered THC. Transient psychomimetic symptoms were seen after THC administration, as measured on the positive and negative syndrome scale (20.6% increase on positive subscale, p<0.001) and the visual analogue scale for psychedelic effects (increase of 10.7 mm on feeling high). Following the combination of THC and olanzapine, the positive subscale increased by only 13.7% and feeling high by only 8.7 mm. This reduction of THC effects on the positive subscale failed to reach statistical significance (p=0.066). However, one-third of the subjects did not show an increase in psychomimetic symptoms after THC alone. Within responders, olanzapine reduced the effects of THC on the positive subscale (p=0.005). Other outcome measures included pharmacokinetics, eye movements, postural stability, pupil/iris ratio, and serum concentrations of cortisol and prolactin.

Heat exposure of Cannabis sativa extracts affects the pharmacokinetic and metabolic profile in healthy male subjects.

The most important psychoactive constituent of CANNABIS SATIVA L. is Δ (9)-tetrahydrocannabinol (THC). Cannabidiol (CBD), another important constituent, is able to modulate the distinct unwanted psychotropic effect of THC. In natural plant extracts of C. SATIVA, large amounts of THC and CBD appear in the form of THCA-A (THC-acid-A) and CBDA (cannabidiolic acid), which can be transformed to THC and CBD by heating. Previous reports of medicinal use of cannabis or cannabis preparations with higher CBD/THC ratios and use in its natural, unheated form have demonstrated that pharmacological effects were often accompanied with a lower rate of adverse effects. Therefore, in the present study, the pharmacokinetics and metabolic profiles of two different C. SATIVA extracts (heated and unheated) with a CBD/THC ratio > 1 were compared to synthetic THC (dronabinol) in a double-blind, randomized, single center, three-period cross-over study involving 9 healthy male volunteers. The pharmacokinetics of the cannabinoids was highly variable. The metabolic pattern was significantly different after administration of the different forms: the heated extract showed a lower median THC plasma AUC (24 h) than the unheated extract of 2.84 vs. 6.59 pmol h/mL, respectively. The later was slightly higher than that of dronabinol (4.58 pmol h/mL). On the other hand, the median sum of the metabolites (THC, 11-OH-THC, THC-COOH, CBN) plasma AUC (24 h) was higher for the heated than for the unheated extract. The median CBD plasma AUC (24 h) was almost 2-fold higher for the unheated than for the heated extract. These results indicate that use of unheated extracts may lead to a beneficial change in metabolic pattern and possibly better tolerability.

A randomized, double-blind, placebo-controlled, crossover study to evaluate the subjective abuse potential and cognitive effects of nabiximols oromucosal spray in subjects with a history of recreational cannabis use.

OBJECTIVE: This study aimed to evaluate the abuse potential and cognitive effects of nabiximols (Sativex, GW Pharma Ltd. Salisbury, UK), an oromucosal spray primarily containing delta­9­tetrahydrocannabinol (THC) and cannabidiol (CBD). METHODS: This was a single­dose, randomized, double­blind, crossover study comparing nabiximols (4, 8, and 16 consecutive sprays: 10.8, 21.6, and 43.2 mg THC, respectively) with dronabinol 20 and 40 mg (synthetic THC: Marinol, Solvay Pharmaceuticals, Brussels, Belgium) and matching placebos in 23 recreational cannabis users. Subjective and cognitive/psychomotor measures were administered over 24 h post­dose. RESULTS: Dronabinol was significantly different from placebo on abuse potential measures, thereby confirming study validity. Nabiximols 10.8 mg was not significantly different from placebo on primary measures but was different on some secondary measures. Nabiximols 21.6 mg was significantly greater than placebo on some primary/secondary measures, whereas nabiximols 43.2 mg showed significant effects on most measures. Nabiximols 10.8 mg was significantly lower than dronabinol doses on most measures ( p < 0.05). Dronabinol 20 mg effects were numerically higher than nabiximols 21.6 mg but were statistically significant only for some measures. Dronabinol 40 mg and nabiximols 43.2 mg were generally not statistically different. CONCLUSIONS: Both dronabinol and nabiximols had significant abuse potential compared with placebo at higher doses. Nabiximols showed similar or slightly less abuse potential compared with dronabinol. Therefore, the abuse potential of nabiximols should be no higher than that of dronabinol.

Plasma cannabinoid pharmacokinetics following controlled oral delta9-tetrahydrocannabinol and oromucosal cannabis extract administration.

BACKGROUND: Sativex(®), a cannabis extract oromucosal spray containing Δ(9)-tetrahydrocannabinol (THC) and cannabidiol (CBD), is currently in phase III trials as an adjunct to opioids for cancer pain treatment, and recently received United Kingdom approval for treatment of spasticity. There are indications that CBD modulates THC's effects, but it is unclear if this is due to a pharmacokinetic and/or pharmacodynamic interaction. METHODS: Cannabis smokers provided written informed consent to participate in this randomized, controlled, double-blind, double-dummy institutional review board-approved study. Participants received 5 and 15 mg synthetic oral THC, low-dose (5.4 mg THC and 5.0 mg CBD) and high-dose (16.2 mg THC and 15.0 mg CBD) Sativex, and placebo over 5 sessions. CBD, THC, 11-hydroxy-THC, and 11-nor- 9-carboxy-THC were quantified in plasma by 2-dimensional GC-MS. Lower limits of quantification were ≤0.25 µg/L. RESULTS: Nine cannabis smokers completed all 5 dosing sessions. Significant differences (P < 0.05) in maximum plasma concentrations (C(max)) and areas under the curve from 0-10.5 h postdose (AUC(0→10.5)) for all analytes were found between low and high doses of synthetic THC and Sativex. There were no statistically significant differences in C(max), time to maximum concentration or in the AUC(0→10.5) between similar oral THC and Sativex doses. Relative bioavailability was calculated to determine the relative rate and extent of THC absorption; 5 and 15 mg oral THC bioavailability was 92.6% (13.1%) and 98.8% (11.0%) of low- and high-dose Sativex, respectively. CONCLUSION: These data suggest that CBD modulation of THC's effects is not due to a pharmacokinetic interaction at these therapeutic doses.

Psychomotor performance in relation to acute oral administration of Delta9-tetrahydrocannabinol and standardized cannabis extract in healthy human subjects.

Abnormalities in psychomotor performance are a consistent finding in schizophrenic patients as well as in chronic cannabis users. The high levels of central cannabinoid (CB(1)) receptors in the basal ganglia, the cerebral cortex and the cerebellum indicate their implication in the regulation of motor activity. Based on the close relationship between cannabis use, the endogenous cannabinoid system and motor disturbances found in schizophrenia, we expected that administration of cannabinoids may change pattern of psychomotor activity like in schizophrenic patients. This prospective, double-blind, placebo-controlled cross-over study investigated the acute effects of cannabinoids on psychomotor performance in 24 healthy right-handed volunteers (age 27.9 +/- 2.9 years, 12 male) by comparing Delta(9)-tetrahydrocannabinol (Delta(9)-THC) and standardized cannabis extract containing Delta(9)-THC and cannabidiol. Psychomotor performance was assessed by using a finger tapping test series. Cannabis extract, but not Delta(9)-THC, revealed a significant reduction of right-hand tapping frequencies that was also found in schizophrenia. As to the pure Delta(9)-THC condition, left-hand tapping frequencies were correlated with the plasma concentrations of the Delta(9)-THC metabolite 11-OH-THC. These effects are thought to be related to cannabinoid actions on CB(1) receptors in the basal ganglia, the cerebral cortex and the cerebellum. Our data further demonstrate that acute CB(1) receptor activation under the cannabis extract condition may also affect intermanual coordination (IMC) as an index of interhemispheric transfer. AIR-Scale scores as a measure of subjective perception of intoxication were dose-dependently related to IMC which was shown by an inverted U-curve. This result may be due to functional changes involving GABAergic and glutamatergic neurotransmission within the corpus callosum.

Psychopathological and cognitive effects of therapeutic cannabinoids in multiple sclerosis: a double-blind, placebo controlled, crossover study.

OBJECTIVES: To study possible psychopathological symptoms and cognitive deficits, abuse induction, as well as general tolerability and effects on quality of life, fatigue and motor function in cannabis-naïve patients with multiple sclerosis (MS) treated with a free-dose cannabis plant extract (Sativex). METHODS: In an 8-week, randomized, double-blind, placebo-controlled, parallel group crossover trial, 17 cannabis-naïve patients with MS were assessed at baseline and at the end of the cannabis and placebo phases of the trial (each of 3 weeks) by means of Symptom Checklist-90 Revised, Self-rating Anxiety Scale, Multiple Sclerosis Functional Composite (of which 1 dimension is the Paced Auditory Serial Additional Test that was used to evaluate cognition), Visual Analogue Scale on health-related quality of life, Multiple Sclerosis Impact Scale-29, and Fatigue Severity Scale. RESULTS: Postplacebo versus postcannabinoid scores showed that no significant differences could be detected on all the variables under study. A significant positive correlation was found between Delta-9-tetrahydrocannabinol blood levels and scores at the General Symptomatic Index and at the "interpersonal sensitivity," "aggressive behaviour," and "paranoiac tendencies" subscales of the Symptom Checklist-90 Revised. No serious adverse events, abuse tendencies, or direct withdrawal symptoms were reported. Increased desire for Sativex with secondary depression was reported in 1 subject. CONCLUSIONS: Cannabinoid treatment did not induce psychopathology and did not impair cognition in cannabis-naïve patients with MS. However, the positive correlation between blood levels of Delta-9-tetrahydrocannabinol and psychopathological scores suggests that at dosages higher than those used in therapeutic settings, interpersonal sensitivity, aggressiveness, and paranoiac features might arise, although greater statistical power would be necessary to confirm this finding.

Dose-dependent effects of smoked cannabis on capsaicin-induced pain and hyperalgesia in healthy volunteers.

BACKGROUND: Although the preclinical literature suggests that cannabinoids produce antinociception and antihyperalgesic effects, efficacy in the human pain state remains unclear. Using a human experimental pain model, the authors hypothesized that inhaled cannabis would reduce the pain and hyperalgesia induced by intradermal capsaicin. METHODS: In a randomized, double-blinded, placebo-controlled, crossover trial in 15 healthy volunteers, the authors evaluated concentration-response effects of low-, medium-, and high-dose smoked cannabis (respectively 2%, 4%, and 8% 9-delta-tetrahydrocannabinol by weight) on pain and cutaneous hyperalgesia induced by intradermal capsaicin. Capsaicin was injected into opposite forearms 5 and 45 min after drug exposure, and pain, hyperalgesia, tetrahydrocannabinol plasma levels, and side effects were assessed. RESULTS: Five minutes after cannabis exposure, there was no effect on capsaicin-induced pain at any dose. By 45 min after cannabis exposure, however, there was a significant decrease in capsaicin-induced pain with the medium dose and a significant increase in capsaicin-induced pain with the high dose. There was no effect seen with the low dose, nor was there an effect on the area of hyperalgesia at any dose. Significant negative correlations between pain perception and plasma delta-9-tetrahydrocannabinol levels were found after adjusting for the overall dose effects. There was no significant difference in performance on the neuropsychological tests. CONCLUSIONS: This study suggests that there is a window of modest analgesia for smoked cannabis, with lower doses decreasing pain and higher doses increasing pain.

Single and multiple doses of rimonabant antagonize acute effects of smoked cannabis in male cannabis users.

RATIONALE: A single 90-mg dose of the cannabinoid CB1 receptor antagonist rimonabant attenuates effects of smoked cannabis in humans. OBJECTIVES: The objective of this study is to evaluate whether repeated daily 40-mg doses of rimonabant can attenuate effects of smoked cannabis to the same extent as a single higher (90 mg) dose. MATERIALS AND METHODS: Forty-two male volunteers received one of three oral drug regimens in a randomized, double blind, parallel group design: (1) 40 mg rimonabant daily for 15 days, (2) placebo for 14 days, then 90 mg rimonabant on day 15, or (3) placebo for 15 days. All participants smoked an active or placebo cannabis cigarette 2 h after medication on days 8 and 15. Subjective effects were measured with visual analog scales and the marijuana-scale of the Addiction Research Center Inventory. RESULTS: Cannabis-induced tachycardia was significantly lower for the 40-mg group on day 8 and for the 40 and 90 mg rimonabant groups on day 15 as compared to placebo. The 40-mg dose significantly decreased peak subjective effects on day 8. Neither the 90-mg nor 40-mg doses significantly decreased peak subjective effects on day 15. Rimonabant treatment did not significantly affect Delta(9)-tetrahydrocannabinnol pharmacokinetics. CONCLUSIONS: Repeated lower daily rimonabant doses (40 mg) attenuated the acute physiological effects of smoked cannabis to a similar degree as a single 90-mg dose; repeated 40-mg doses attenuated subjective effects after 8 but not 15 days.

Delta(9)-tetrahydrocannabinol, 11-hydroxy-delta(9)-tetrahydrocannabinol and 11-nor-9-carboxy-delta(9)-tetrahydrocannabinol in human plasma after controlled oral administration of cannabinoids.

A clinical study to investigate the pharmacokinetics and pharmacodynamics of oral tetrahydrocannabinol was performed. This randomized, double-blind, placebo-controlled, within-subject, inpatient study compared the effects of THC-containing hemp oils in liquid and capsule form to dronabinol (synthetic THC) in doses used for appetite stimulation. The National Institute on Drug Abuse Institutional Review Board approved the protocol and each participant provided informed consent. Detection times and concentrations of THC, 11-hydroxy-Delta-tetrahydrocannabinol (11-OH-THC), and 11-nor-9-carboxy-Delta-tetrahydrocannabinol (THCCOOH) in plasma were determined by gas chromatography-mass spectrometry [limits of quantification (LOQ)=0.5, 0.5, and 1.0 ng/mL, respectively] after oral THC administration. Six volunteers ingested liquid hemp oil (0.39 and 14.8 mg THC/d), hemp oil in capsules (0.47 mg THC/d), dronabinol capsules (7.5 mg THC/d), and placebo. Plasma specimens were collected during and after each dosing condition. THC and 11-OH-THC concentrations were low and never exceeded 6.1 ng/mL. Analytes were detectable 1.5 hour after initiating dosing with the 7.5 mg THC/d regimen and 4.5 hour after starting the 14.8 mg THC/d sessions. THCCOOH was detected 1.5 hour after the first dose, except for the 0.47 mg THC/d session, which required 4.5 hour for concentrations to reach the LOQ. THCCOOH concentrations peaked at 3.1 ng/mL during dosing with the low-dose hemp oils. Plasma THC and 11-OH-THC concentrations were negative for all participants at all doses within 15.5 hours after the last THC dose. Plasma THCCOOH persisted for at least 39.5 hours after the end of dosing and at much higher concentrations (up to 43.0 ng/mL). This study demonstrated that subjects who used high THC content hemp oil (347 mug/mL) as a dietary supplement had THC and metabolites in plasma in quantities comparable to those of patients using dronabinol for appetite stimulation. There was a significant correlation between body mass index and Cmax and body mass index and number of specimens positive for THC and 11-OH-THC.

Simultaneous and sensitive analysis of THC, 11-OH-THC, THC-COOH, CBD, and CBN by GC-MS in plasma after oral application of small doses of THC and cannabis extract.

Besides the psychoactive Delta(9)-tetrahydrocannabinol (THC), hashish and marijuana as well as cannabis-based medicine extracts contain varying amounts of cannabidiol (CBD) and of the degradation product cannabinol (CBN). The additional determination of these compounds is interesting from forensic and medical points of view because it can be used for further proof of cannabis exposure and because CBD is known to modify the effects of THC. Therefore, a method for the simultaneous quantitative determination of THC, its metabolites 11-hydroxy-Delta(9)-tetrahydrocannabinol (11-OH-THC) and 11-nor-9-carboxy-Delta(9)-tetrahydrocannabinol (THC-COOH), CBD and CBN from plasma was developed. The method was based on automatic solid-phase extraction with C(18) ec columns, derivatization with N,O-bistrimethylsilyltrifluoroacetamide (BSTFA), and gas chromatography-electron impact ionization-mass spectrometry (GC-EI-MS) with deuterated standards. The limits of detection were between 0.15 and 0.29 ng/mL for THC, 11-OH-THC, THC-COOH, and CBD and 1.1 ng/mL for CBN. The method was applied in a prospective pharmacokinetic study after single oral administration of 10 mg THC alone or together with 5.4 mg CBD in cannabis extract. The maximum plasma concentrations after cannabis extract administration ranged between 1.2 and 10.3 ng/mL (mean 4.05 ng/mL) for THC, 1.8 and 12.3 ng/mL (mean 4.9 ng/mL) for 11-OH-THC, 19 and 71 ng/mL (mean 35 ng/mL) for THC-COOH, and 0.2 and 2.6 ng/mL (mean 0.95 ng/mg) for CBD. The peak concentrations (mean values) of THC, 11-OH-THC, THC-COOH, and CBD were observed at 56, 82, 115, and 60 min, respectively, after intake. CBN was not detected. Caused by the strong first-pass metabolism, the concentrations of the metabolites were increased during the first hours after drug administration when compared to literature data for smoking. Therefore, the concentration ratio 11-OH-THC/THC was discussed as a criterion for distinguishing oral from inhalative cannabis consumption.