Tetrahydrocannabinol in Behavioral Disturbances in Dementia: A Crossover Randomized Controlled Trial

OBJECTIVES

Neuropsychiatric symptoms (NPS) are highly prevalent in dementia, but effective pharmacotherapy without important side effects is lacking. This study aims to assess the efficacy and safety of oral tetrahydrocannabinol (THC) in the treatment of NPS in dementia.

DESIGN

Randomized, double-blind, placebo-controlled, repeated crossover trial, consisting of six treatment blocks of 2 weeks each.

SETTING

Two hospital sites in The Netherlands, September 2011 to December 2013.

PARTICIPANTS

Patients with dementia and clinically relevant NPS.

INTERVENTION

Within each block THC (0.75 mg twice daily in blocks 1-3 and 1.5 mg twice daily in blocks 4-6) and placebo were administered in random order for 3 consecutive days, followed by a 4-day washout.

MEASUREMENTS

Primary outcome was change in Neuropsychiatric Inventory (NPI) score. Analyses were performed intention-to-treat. Data from all subjects were used without imputation. Sample size required for a power of 80% was 20 patients, because of repeated crossover.

RESULTS

22 patients (15 men, mean age 76.4 [5.3] years) were included, of whom 20 (91%) completed the trial. THC did not reduce NPI compared to placebo (blocks 1-3: 1.8, 97.5% CI: -2.1 to 5.8; blocks 4-6: -2.8, 97.5% CI: -7.4 to 1.8). THC was well tolerated, as assessed by adverse event monitoring, vital signs, and mobility. The incidence of adverse events was similar between treatment groups. Four non-related serious adverse events occurred.

CONCLUSIONS

This is the largest randomized controlled trial studying the efficacy of THC for NPS, to date. Oral THC did not reduce NPS in dementia, but was well tolerated by these vulnerable patients, supporting future higher dosing studies.

Inhibiting Heat Shock Proteins Can Potentiate the Cytotoxic Effect of Cannabidiol in Human Glioma Cells

Cannabinoids possess a number of characteristics that make them putative anticancer drugs, and their value as such is currently being explored in a number of clinical studies. To further understand the roles that cannabinoids may have, we performed gene expression profiling in glioma cell lines cultured with cannabidiol (CBD) and/or Δ9-tetrahydrocannabinol (THC), and pursued targets identified by this screening. Results showed that a large number of genes belonging to the heat shock protein (HSP) super-family were up-regulated following treatment, specifically with CBD. Increases were observed both at the gene and protein levels and arose as a consequence of increased generation of ROS by CBD, and correlated with an increase in a number of HSP client proteins. Furthermore, increases impeded the cytotoxic effect of CBD; an effect that was improved by co-culture with pharmacalogical inhibitors of HSPs. Similarly, culturing glioma cells with CBD and HSP inhibitors increased radiosensitivity when compared to CBD-alone. Taken together, these data indicate that the cytotoxic effects of CBD can be diminished by HSPs that indirectly rise as a result of CBD use, and that the inclusion of HSP inhibitors in CBD treatment regimens can enhance the overall effect.

Hair analysis for Δ(9) -tetrahydrocannabinolic acid A (THCA-A) and Δ(9) -tetrahydrocannabinol (THC) after handling cannabis plant material

A previous study has shown that Δ(9) -tetrahydrocannabinolic acid A (THCA-A), the non-psychoactive precursor of Δ(9) -tetrahydrocannabinol (THC) in the cannabis plant does not get incorporated in relevant amounts into the hair through the bloodstream after repeated oral intake. However, THCA-A can be measured in forensic hair samples in concentrations often exceeding the detected THC concentrations. To investigate whether the handling of cannabis plant material prior to consumption is a contributing factor for THC-positive hair results and also the source for THCA-A findings in hair, a study comprising ten participants was conducted. In this study, the participants rolled a marijuana joint on five consecutive days and hair samples of each participant were obtained. Urine samples were taken to exclude cannabis consumption prior to and during the study. THCA-A and THC could be detected in the hair samples from all participants taken at the end of the exposure period (concentration range: 15-1800 pg/mg for THCA-A and < 10-93 pg/mg for THC). Four weeks after the first exposure, THCA-A could still be detected in the hair samples of nine participants (concentration range: 4-57 pg/mg). Furthermore, THC could be detected in the hair samples of five participants (concentration range: < 10-17 pg/mg). Based on these results, it can be concluded that at least parts of the THC as well as the major part of THCA-A found in routine hair analysis derives from external contamination caused by direct transfer through contaminated fingers. This finding is of particular interest in interpreting THC-positive hair results of children or partners of cannabis users, where such a transfer can occur due to close body contact. Analytical findings may be wrongly interpreted as a proof of consumption or at least passive exposure to cannabis smoke. Such misinterpretation could lead to severe consequences for the people concerned.

CB1 cannabinoid receptors mediate endochondral skeletal growth attenuation by Δ9-tetrahydrocannabinol

The endocannabinoid (EC) system regulates bone mass. Because cannabis use during pregnancy results in stature shorter than normal, we examined the role of the EC system in skeletal elongation. We show that CB1 and CB2 cannabinoid receptors are expressed specifically in hypertrophic chondrocytes of the epiphyseal growth cartilage (EGC), which drives vertebrate growth. These cells also express diacylglycerol lipases, critical biosynthetic enzymes of the main EC, and 2-arachidonoylglycerol (2-AG), which is present at significant levels in the EGC. Femora of CB1- and/or CB2-deficient mice at the end of the rapid growth phase are longer compared to wild-type (WT) animals. We find that Δ(9) -tetrahydrocannabinol (THC) slows skeletal elongation of female WT and CB2-, but not CB1-, deficient mice, which is reflected in femoral and lumbar vertebral body length. This in turn results in lower body weight, but unaltered fat content. THC inhibits EGC chondrocyte hypertrophy in ex vivo cultures and reduces the hypertrophic cell zone thickness of CB1-, but not CB2-, deficient mice. These results demonstrate a local growth-restraining EC system in the EGC. The relevance of the present findings to humans remains to be studied.

Medical marijuana for cancer

Answer questions and earn CME/CNE Marijuana has been used for centuries, and interest in its medicinal properties has been increasing in recent years. Investigations into these medicinal properties has led to the development of cannabinoid pharmaceuticals such as dronabinol, nabilone, and nabiximols. Dronabinol is best studied in the treatment of nausea secondary to cancer chemotherapy and anorexia associated with weight loss in patients with acquired immune deficiency syndrome, and is approved by the US Food and Drug Administration for those indications. Nabilone has been best studied for the treatment of nausea secondary to cancer chemotherapy. There are also limited studies of these drugs for other conditions. Nabiximols is only available in the United States through clinical trials, but is used in Canada and the United Kingdom for the treatment of spasticity secondary to multiple sclerosis and pain. Studies of marijuana have concentrated on nausea, appetite, and pain. This article will review the literature regarding the medical use of marijuana and these cannabinoid pharmaceuticals (with emphasis on indications relevant to oncology), as well as available information regarding adverse effects of marijuana use.

Urine toxicology screen in multiple sleep latency test: the correlation of positive tetrahydrocannabinol, drug negative patients, and narcolepsy

OBJECTIVE

Drugs can influence results of multiple sleep latency tests (MSLT). We sought to identify the effect of marijuana on MSLT results in pediatric patients evaluated for excessive daytime sleepiness (EDS).

METHODS

This is a retrospective study of urine drug screens performed the morning before MSLT in 383 patients <21 years old referred for EDS. MSLT results were divided into those with (1) (-) urine drug screens, (2) urine drug screens (+) for tetrahydrocannabinol (THC) alone or THC plus other drugs, and (3) urine drug screens (+) for drugs other than THC. Groups were compared with Fisher exact tests or one-way ANOVA.

RESULTS

38 (10%) urine drug tests were (+): 14 for THC and 24 for other drugs. Forty-three percent of patients with drug screen (+) for THC had MSLT findings consistent with narcolepsy, 0% consistent with idiopathic hypersomnia, 29% other, and 29% normal. This was statistically different from those with (-) screens (24% narcolepsy, 20% idiopathic hypersomnia, 6% other, 50% normal), and those (+) for drugs other than THC (17% narcolepsy, 33% idiopathic hypersomnia, 4% other, 46% normal (p = 0.01). Six percent (6/93) of patients with MSLT findings consistent with narcolepsy were drug screen (+) for THC; 71% of patients with drug screen (+) for THC had multiple sleep onset REM periods (SOREMS). There were no (+) urine drug screens in patients <13 years old.

CONCLUSION

Many pediatric patients with (+) urine drug screens for THC met MSLT criteria for narcolepsy or had multiple SOREMs. Drug screening is important in interpreting MSLT findings for children ≥13 years.

Evaluation of Phytocannabinoids from High Potency Cannabis sativa using In Vitro Bioassays to Determine Structure-Activity Relationships for Cannabinoid Receptor 1 and Cannabinoid Receptor 2

Cannabis has been around for thousands of years and has been used recreationally, medicinally, and for fiber. Over 500 compounds have been isolated from Cannabis sativa with approximately 105 being cannabinoids. Of those 105 compounds, Δ9-tetrahydrocannabinol has been determined as the primary constituent, which is also responsible for the psychoactivity associated with Cannabis. Cannabinoid receptors belong to the large superfamily of G protein-coupled receptors. Targeting the cannabinoid receptors has the potential to treat a variety of conditions such as pain, neurodegeneration, appetite, immune function, anxiety, cancer, and others. Developing in vitro bioassays to determine binding and functional activity of compounds has the ability to lead researchers to develop a safe and effective drug that may target the cannabinoid receptors. Using radioligand binding and functional bioassays, a structure-activity relationship for major and minor cannabinoids was developed.

Marijuana and body weight

Acute marijuana use is classically associated with snacking behavior (colloquially referred to as "the munchies"). In support of these acute appetite-enhancing effects, several authorities report that marijuana may increase body mass index in patients suffering from human immunodeficiency virus and cancer. However, for these medical conditions, while appetite may be stimulated, some studies indicate that weight gain is not always clinically meaningful. In addition, in a study of cancer patients in which weight gain did occur, it was less than the comparator drug (megestrol). However, data generally suggest that acute marijuana use stimulates appetite, and that marijuana use may stimulate appetite in low-weight individuals. As for large epidemiological studies in the general population, findings consistently indicate that users of marijuana tend to have lower body mass indices than nonusers. While paradoxical and somewhat perplexing, these findings may be explained by various study confounds, such as potential differences between acute versus chronic marijuana use; the tendency for marijuana use to be associated with other types of drug use; and/or the possible competition between food and drugs for the same reward sites in the brain. Likewise, perhaps the effects of marijuana are a function of initial weight status-i.e., maybe marijuana is a metabolic regulatory substance that increases body weight in low-weight individuals but not in normal-weight or overweight individuals. Only further research will clarify the complex relationships between marijuana and body weight.

Dronabinol and chronic pain: importance of mechanistic considerations

INTRODUCTION

Although medicinal cannabis has been used for many centuries, the therapeutic potential of delta-9-tetrahydrocannabinol (Δ9-THC; international non-proprietary name = dronabinol) in current pain management remains unclear. Several pharmaceutical products with defined natural or synthesized Δ9-THC content have been developed, resulting in increasing numbers of clinical trials investigating the analgesic efficacy of dronabinol in various pain conditions. Different underlying pain mechanisms, including sensitization of nociceptive sensory pathways and alterations in cognitive and autonomic processing, might explain the varying analgesic effects of dronabinol in chronic pain states.

AREAS COVERED

The pharmacokinetics, pharmacodynamics and mechanisms of action of products with a defined dronabinol content are summarized. Additionally, randomized clinical trials investigating the analgesic efficacy of pharmaceutical cannabis based products are reviewed for the treatment of chronic nonmalignant pain.

EXPERT OPINION

We suggest a mechanism-based approach beyond measurement of subjective pain relief to evaluate the therapeutic potential of dronabinol in chronic pain management. Development of objective mechanistic diagnostic biomarkers reflecting altered sensory and cognitive processing in the brain is essential to evaluate dronabinol induced analgesia, and to permit identification of responders and/or non-responders to dronabinol treatment.

A survey of synthetic cannabinoid consumption by current cannabis users

BACKGROUND

Despite growing concern about the increased rates of synthetic cannabinoid (SC) use and their effects, only limited data are available that addresses these issues. This study assessed the extent of SC product use and reported effects among a cohort of adult marijuana and tobacco users.

METHODS

A brief telephone interview was conducted with individuals who had given permission to be contacted for future research while screening for a cannabis/nicotine dependence medication development study (NCT01204723).

RESULTS

Respondents (N = 42; 88% participation rate) were primarily young adults, male, racially diverse, and high school graduates. Nearly all currently smoked tobacco and cannabis, with 86% smoking cannabis on 5 or more days per week. Nearly all (91%) were familiar with SC products, half (50%) reported smoking SC products previously, and a substantial minority (24%) reported current use (i.e., past month). Despite a federal ban on 5 common SCs, which went into effect on March 1, 2011, a number of respondents reported continued SC product use. Common reasons reported for use included, but were not limited to, seeking a new "high" similar to that produced by marijuana and avoiding drug use detection via a positive urine screen. The primary side effects were trouble thinking clearly, headache, dry mouth, and anxiety. No significant differences were found between synthetic cannabinoid product users (ever or current) and nonusers by demographics or other characteristics.

CONCLUSIONS

Among current marijuana and tobacco users, SC product consumption was common and persisted despite a federal ban. The primary reasons for the use of SC-containing products seem to be to evade drug detection and to experience a marijuana-like high.

Endocannabinoid signaling in the etiology and treatment of major depressive illness

The purpose of this review is to examine human and preclinical data that are relevant to the following hypotheses. The first hypothesis is that deficient CB1R-mediated signaling results in symptoms that mimic those seen in depression. The second hypothesis is that activation of CB1R-mediated signaling results in behavioral, endocrine and other effects that are similar to those produced by currently used antidepressants. The third hypothesis is that conventional antidepressant therapies act through enhanced CB1R mediated signaling. Together the available data indicate that activators of CB1R signaling, particularly inhibitors of fatty acid amide hydrolase, should be considered for clinical trials for the treatment of depression.

Influence of aripiprazole pretreatment on the reinforcing effects of methamphetamine in humans

Methamphetamine use disorders remain a significant public health concern. Methamphetamine produces its behavioral effects by facilitating release of monoamines like dopamine (DA) and serotonin (5-HT). Results from animal studies show that acute pretreatment with DA and 5-HT antagonists attenuates the effects of methamphetamine, but this area remains largely unexplored in humans. This study sought to assess whether aripiprazole, a partial agonist at D2/5-HT1A receptors and an antagonist at 5-HT2A receptors, would attenuate the reinforcing and subject-rated effects of oral methamphetamine. Seven subjects with histories of recreational stimulant use completed a placebo-controlled, crossover, double-blind protocol in which they first sampled doses of oral methamphetamine (0, 4, 8 or 16 mg) following acute pretreatment with aripiprazole (0 and 15 mg). During each Sampling Session, subjects also completed a battery of subject-rated, cardiovascular, and other performance measures. In subsequent Self-Administration Sessions, subjects were provided the opportunity to earn the previously sampled methamphetamine dose on a progressive-ratio procedure. Methamphetamine functioned as a reinforcer, and produced prototypical stimulant-like subject-rated and cardiovascular effects (e.g., increased ratings of Stimulated; elevated blood pressure). Aripiprazole reduced methamphetamine self-administration and attenuated some of the positive subject-rated effects of methamphetamine (e.g., ratings of Like Drug). These results indicate that acute aripiprazole pretreatment attenuates the abuse-related effects of methamphetamine.

Δ-Tetrahydrocannabinol induces cytotoxicity in macrophage J774-1 cells: involvement of cannabinoid receptor 2 and p38 MAPK

Tetrahydrocannabinol (THC), a psychoactive component of marijuana, is known to exert cytotoxicity in immune cells. In the present study, we examined the cytotoxicity of Δ⁸-THC in mouse macrophage J774-1 cells and a possible involvement of cannabinoid receptors and stress-responsive mitogen-activated protein kinases (MAPKs) in the cytotoxic process. J774-1 cells were treated with Δ⁸-THC (0-20 μM) for up to 6 h. As measured by the MTT and LDH assays, Δ⁸-THC induced cell death of J774-1 cells in a concentration- and/or exposure time-dependent manner. Δ⁸-THC-induced cell damage was associated with vacuole formation, cell swelling, chromatin condensation, and nuclear fragmentation. The cytotoxic effect of Δ⁸-THC was significantly prevented by a caspase-1 inhibitor Ac-YVAD-cmk but not a caspase-3 inhibitor z-DEVD-fmk. The pretreatment with SR144528, a CB₂ receptor-selective antagonist, effectively suppressed Δ⁸-THC-induced cytotoxicity in J774-1 cells, which exclusively expressed CB₂ receptors as indicated by real-time polymerase chain reaction analysis. In contrast, AM251, a CB₁ receptor-selective antagonist, did not affect the cytotoxicity. Pertussis toxin and α-tocopherol significantly attenuated Δ⁸-THC-induced cytotoxicity suggesting that G(i/o) protein coupling signal transduction and oxidative stress are responsible for the cytotoxicity. Δ⁸-THC stimulated the phosphorylation of p38 MAPK and c-Jun N-terminal kinase (JNK) in J774-1 cells, which were effectively antagonized by the pretreatment with SR144528. In addition, SB203580, a p38 MARK inhibitor, significantly attenuated the cytotoxic effect of Δ⁸-THC, whereas SP600125, a JNK inhibitor, significantly enhanced the cytotoxicity. These results suggest that the cytotoxicity of Δ⁸-THC to J774-1 cells is exerted mediated through the CB₂ receptor followed by the activation of p38 MAPK.

Does Cannabidiol Protect Against Adverse Psychological Effects of THC?

The recreational use of cannabis can have persistent adverse effects on mental health. Delta-9-tetrahydrocannabinol (THC) is the main psychoactive constituent of cannabis, and most, if not all, of the effects associated with the use of cannabis are caused by THC. Recent studies have suggested a possible protective effect of another cannabinoid, cannabidiol (CBD). A literature search was performed in the bibliographic databases PubMed, PsycINFO, and Web of Science using the keyword "cannabidiol." After removing duplicate entries, 1295 unique titles remained. Based on the titles and abstracts, an initial selection was made. The reference lists of the publications identified in this manner were examined for additional references. Cannabis is not a safe drug. Depending on how often someone uses, the age of onset, the potency of the cannabis that is used and someone's individual sensitivity, the recreational use of cannabis may cause permanent psychological disorders. Most recreational users will never be faced with such persistent mental illness, but in some individuals cannabis use leads to undesirable effects: cognitive impairment, anxiety, paranoia, and increased risks of developing chronic psychosis or drug addiction. Studies examining the protective effects of CBD have shown that CBD can counteract the negative effects of THC. However, the question remains of how the laboratory results translate to the types of cannabis that are encountered by real-world recreational users.

Oral fluid cannabinoid concentrations following controlled smoked cannabis in chronic frequent and occasional smokers

Oral fluid (OF) is an alternative biological matrix for monitoring cannabis intake in drug testing, and drugged driving (DUID) programs, but OF cannabinoid test interpretation is challenging. Controlled cannabinoid administration studies provide a scientific database for interpreting cannabinoid OF tests. We compared differences in OF cannabinoid concentrations from 19 h before to 30 h after smoking a 6.8% THC cigarette in chronic frequent and occasional cannabis smokers. OF was collected with the Statsure Saliva Sampler™ OF device. 2D-GC-MS was used to quantify cannabinoids in 357 OF specimens; 65 had inadequate OF volume within 3 h after smoking. All OF specimens were THC-positive for up to 13.5 h after smoking, without significant differences between frequent and occasional smokers over 30 h. Cannabidiol (CBD) and cannabinol (CBN) had short median last detection times (2.5-4 h for CBD and 6-8 h for CBN) in both groups. THCCOOH was detected in 25 and 212 occasional and frequent smokers' OF samples, respectively. THCCOOH provided longer detection windows than THC in all frequent smokers. As THCCOOH is not present in cannabis smoke, its presence in OF minimizes the potential for false positive results from passive environmental smoke exposure, and can identify oral THC ingestion, while OF THC cannot. THC ≥ 1 μg/L, in addition to CBD ≥ 1 μg/L or CBN ≥ 1 μg/L suggested recent cannabis intake (≤13.5 h), important for DUID cases, whereas THC ≥ 1 μg/L or THC ≥ 2 μg/L cutoffs had longer detection windows (≥30 h), important for workplace testing. THCCOOH windows of detection for chronic, frequent cannabis smokers extended beyond 30 h, while they were shorter (0-24 h) for occasional cannabis smokers.

Critical appraisal of the potential use of cannabinoids in cancer management

Cannabinoids have been attracting a great deal of interest as potential anticancer agents. Originally derived from the plant Cannabis sativa, there are now a number of endo-, phyto- and synthetic cannabinoids available. This review summarizes the key literature to date around the actions, antitumor activity, and mechanisms of action for this broad range of compounds. Cannabinoids are largely defined by an ability to activate the cannabinoid receptors – CB₁ or CB₂. The action of the cannabinoids is very dependent on the exact ligand tested, the dose, and the duration of exposure. Some cannabinoids, synthetic or plant-derived, show potential as therapeutic agents, and evidence across a range of cancers and evidence in vitro and in vivo is starting to be accumulated. Studies have now been conducted in a wide range of cell lines, including glioma, breast, prostate, endothelial, liver, and lung. This work is complemented by an increasing body of evidence from in vivo models. However, many of these results remain contradictory, an issue that is not currently able to be resolved through current knowledge of mechanisms of action. While there is a developing understanding of potential mechanisms of action, with the extracellular signal-regulated kinase pathway emerging as a critical signaling juncture in combination with an important role for ceramide and lipid signaling, the relative importance of each pathway is yet to be determined. The interplay between the intracellular pathways of autophagy versus apoptosis is a recent development that is discussed. Overall, there is still a great deal of conflicting evidence around the future utility of the cannabinoids, natural or synthetic, as therapeutic agents.

Differential expression of intracellular and extracellular CB(2) cannabinoid receptor protein by human peripheral blood leukocytes

mRNA encoding for the CB(2) cannabinoid receptor is expressed by many subsets of human peripheral blood leukocytes (PBL), but little is known about the resulting protein expression and function. Employing clones from the A549 and 293T cell lines that were constructed to express both full-length human CB(2) and GFP, we developed a flow cytometry assay for characterizing CB(2) protein expression. A monoclonal antibody directed against human CB(2) selectively stained the surface of transduced but not parental cell lines. When cells were fixed and permeabilized, imaging flow cytometry identified large stores of intracellular protein. Total cellular staining for CB(2) corresponded closely with the level of GFP expression. When exposed to Δ(9)-tetrahydrocannabinol, CB(2)-expressing cells internalized cell surface CB(2) receptors in a time- and dose-dependent manner. Applying these approaches to human PBL, CB(2) protein was identified on the surface of human B cells but not on T cells or monocytes. In contrast, when PBL were fixed and permeabilized, intracellular CB(2) expression was readily detected in all three subsets by both conventional and imaging flow cytometry. Similar to the protein expression pattern observed in fixed and permeabilized PBL, purified B cells, T cells, and monocytes expressed relatively equal levels of CB(2) mRNA by quantitative real-time RT-PCR. Our findings confirm that human PBL express CB(2) protein but that its distribution is predominantly intracellular with only B cells expressing CB(2) protein at the extracellular membrane. The differential role of intracellular and extracellular CB(2) receptors in mediating ligand signaling and immune function remains to be determined.

Effects of delta-9-tetrahydrocannabinol on evaluation of emotional images

There is growing evidence that drugs of abuse alter processing of emotional information in ways that could be attractive to users. Our recent report that Δ⁹-tetrahydrocannabinol (THC) diminishes amygdalar activation in response to threat-related faces suggests that THC may modify evaluation of emotionally-salient, particularly negative or threatening, stimuli. In this study, we examined the effects of acute THC on evaluation of emotional images. Healthy volunteers received two doses of THC (7.5 and 15 mg; p.o.) and placebo across separate sessions before performing tasks assessing facial emotion recognition and emotional responses to pictures of emotional scenes. THC significantly impaired recognition of facial fear and anger, but it only marginally impaired recognition of sadness and happiness. The drug did not consistently affect ratings of emotional scenes. THC's effects on emotional evaluation were not clearly related to its mood-altering effects. These results support our previous work, and show that THC reduces perception of facial threat. Nevertheless, THC does not appear to positively bias evaluation of emotional stimuli in general.

Heterogeneity in the composition of marijuana seized in California

BACKGROUND

Marijuana contains multiple cannabinoids. Most attention is given to delta-9-tetrahydrocannabinol (THC) which produces euphoria and in some cases anxiety and panic reactions. Research suggests that another cannabinoid, cannabidiol (CBD), may offset some of these effects. Thus, there is growing interest in the health consequences of the THC to CBD ratio for marijuana.

METHODS

Using data from over 5000 marijuana samples in California from 1996 to 2008, we examine changes in the median THC-level, median CBD-level, and median THC:CBD-ratio.

RESULTS

The median THC-level and median THC:CBD-ratio have dramatically increased for seizures in California, particularly north of the Mexican border.

CONCLUSION

Research on the consequences of the THC:CBD ratio should continue, especially as more attention is devoted to thinking about how to regulate marijuana for medical and recreational use. Researchers should also consider the lack of uniformity in the chemical composition of marijuana when evaluating its health effects.

Role of the cannabinoid system in pain control and therapeutic implications for the management of acute and chronic pain episodes

Cannabis extracts and synthetic cannabinoids are still widely considered illegal substances. Preclinical and clinical studies have suggested that they may result useful to treat diverse diseases, including those related with acute or chronic pain. The discovery of cannabinoid receptors, their endogenous ligands, and the machinery for the synthesis, transport, and degradation of these retrograde messengers, has equipped us with neurochemical tools for novel drug design. Agonist-activated cannabinoid receptors, modulate nociceptive thresholds, inhibit release of pro-inflammatory molecules, and display synergistic effects with other systems that influence analgesia, especially the endogenous opioid system. Cannabinoid receptor agonists have shown therapeutic value against inflammatory and neuropathic pains, conditions that are often refractory to therapy. Although the psychoactive effects of these substances have limited clinical progress to study cannabinoid actions in pain mechanisms, preclinical research is progressing rapidly. For example, CB(1)mediated suppression of mast cell activation responses, CB(2)-mediated indirect stimulation of opioid receptors located in primary afferent pathways, and the discovery of inhibitors for either the transporters or the enzymes degrading endocannabinoids, are recent findings that suggest new therapeutic approaches to avoid central nervous system side effects. In this review, we will examine promising indications of cannabinoid receptor agonists to alleviate acute and chronic pain episodes. Recently, Cannabis sativa extracts, containing known doses of tetrahydrocannabinol and cannabidiol, have granted approval in Canada for the relief of neuropathic pain in multiple sclerosis. Further double-blind placebo-controlled clinical trials are needed to evaluate the potential therapeutic effectiveness of various cannabinoid agonists-based medications for controlling different types of pain.

Simultaneous quantification of cannabinoids and metabolites in oral fluid by two-dimensional gas chromatography mass spectrometry

Development and validation of a method for simultaneous identification and quantification of Delta9-tetrahydrocannabinol (THC), cannabidiol (CBD), cannabinol (CBN), and metabolites 11-hydroxy-THC (11-OH-THC) and 11-nor-9-carboxy-THC (THCCOOH) in oral fluid. Simultaneous analysis was problematic due to different physicochemical characteristics and concentration ranges. Neutral analytes, such as THC and CBD, are present in ng/mL, rather than pg/mL concentrations, as observed for the acidic THCCOOH biomarker in oral fluid. THCCOOH is not present in cannabis smoke, definitively differentiating cannabis use from passive smoke exposure. THC, 11-OH-THC, THCCOOH, CBD, and CBN quantification was achieved in a single oral fluid specimen collected with the Quantisal device. One mL oral fluid/buffer solution (0.25 mL oral fluid and 0.75 mL buffer) was applied to conditioned CEREX Polycrom THC solid-phase extraction (SPE) columns. After washing, THC, 11-OH-THC, CBD, and CBN were eluted with hexane/acetone/ethyl acetate (60:30:20, v/v/v), derivatized with N,O-bis-(trimethylsilyl)trifluoroacetamide and quantified by two-dimensional gas chromatography electron ionization mass spectrometry (2D-GCMS) with cold trapping. Acidic THCCOOH was separately eluted with hexane/ethyl acetate/acetic acid (75:25:2.5, v/v/v), derivatized with trifluoroacetic anhydride and hexafluoroisopropanol, and quantified by the more sensitive 2D-GCMS-electron capture negative chemical ionization (NCI-MS). Linearity was 0.5-50 ng/mL for THC, 11-OH-THC, CBD and 1-50 ng/mL for CBN. The linear dynamic range for THCCOOH was 7.5-500 pg/mL. Intra- and inter-assay imprecision as percent RSD at three concentrations across the linear dynamic range were 0.3-6.6%. Analytical recovery was within 13.8% of target. This new SPE 2D-GCMS assay achieved efficient quantification of five cannabinoids in oral fluid, including pg/mL concentrations of THCCOOH by combining differential elution, 2D-GCMS with electron ionization and negative chemical ionization. This method will be applied to quantification of cannabinoids in oral fluid specimens from individuals participating in controlled cannabis and Sativex (50% THC and 50% CBD) administration studies, and during cannabis withdrawal.

Extended urinary Delta9-tetrahydrocannabinol excretion in chronic cannabis users precludes use as a biomarker of new drug exposure

BACKGROUND

Generally, urinary 11-nor-9-carboxy-Delta9-tetrahydrocannabinol (THCCOOH) after alkaline hydrolysis is monitored to detect cannabis exposure, although last use may have been weeks prior in chronic cannabis users. Delta9-Tetrahydrocannabinol (THC) and 11-hydroxy-THC (11-OH-THC) concentrations in urine following Escherichia coli beta-glucuronidase hydrolysis were proposed as biomarkers of recent (within 8h) cannabis use.

OBJECTIVE

To test the validity of THC and 11-OH-THC in urine as indicators of recent cannabis use.

METHODS

Monitor urinary cannabinoid excretion in 33 chronic cannabis smokers who resided on a secure research unit under 24h continuous medical surveillance. All urine specimens were collected individually ad libidum for up to 30 days, were hydrolyzed with a tandem E. coli beta-glucuronidase/base procedure, and analyzed for THC, 11-OH-THC and THCCOOH by one- and two-dimensional-cryotrap gas chromatography mass spectrometry (2D-GCMS) with limits of quantification of 2.5 ng/mL.

RESULTS

Extended excretion of THC and 11-OH-THC in chronic cannabis users' urine was observed during monitored abstinence; 14 of 33 participants had measurable THC in specimens collected at least 24h after abstinence initiation. Seven subjects had measurable THC in urine for 3, 3, 4, 7, 7, 12, and 24 days after cannabis cessation. 11-OH-THC and THCCOOH were detectable in urine specimens from one heavy, chronic cannabis user for at least 24 days.

CONCLUSION

For the first time, extended urinary excretion of THC and 11-OH-THC is documented for at least 24 days, negating their effectiveness as biomarkers of recent cannabis exposure, and substantiating long terminal elimination times for urinary cannabinoids following chronic cannabis smoking.

Gene-environment interplay between cannabis and psychosis

Cannabis use is considered a contributory cause of schizophrenia and psychotic illness. However, only a small proportion of cannabis users develop psychosis. This can partly be explained by the amount and duration of the consumption of cannabis and by its strength but also by the age at which individuals are first exposed to cannabis. Genetic factors, in particular, are likely to play a role in the short- and the long-term effects cannabis may have on psychosis outcome. This review will therefore consider the interplay between genes and exposure to cannabis in the development of psychotic symptoms and schizophrenia. Studies using genetic, epidemiological, experimental, and observational techniques will be discussed to investigate gene-environment correlation gene-environment interaction, and higher order interactions within the cannabis-psychosis association. Evidence suggests that mechanisms of gene-environment interaction are likely to underlie the association between cannabis and psychosis. In this respect, multiple variations within multiple genes--rather than single genetic polymorphisms--together with other environmental factors (eg, stress) may interact with cannabis to increase the risk of psychosis. Further research on these higher order interactions is needed to better understand the biological pathway by which cannabis use, in some individuals, may cause psychosis in the short- and long term.

Cannabinoids in the management of difficult to treat pain

This article reviews recent research on cannabinoid analgesia via the endocannabinoid system and non-receptor mechanisms, as well as randomized clinical trials employing cannabinoids in pain treatment. Tetrahydrocannabinol (THC, Marinol((R))) and nabilone (Cesamet((R))) are currently approved in the United States and other countries, but not for pain indications. Other synthetic cannabinoids, such as ajulemic acid, are in development. Crude herbal cannabis remains illegal in most jurisdictions but is also under investigation. Sativex((R)), a cannabis derived oromucosal spray containing equal proportions of THC (partial CB(1) receptor agonist ) and cannabidiol (CBD, a non-euphoriant, anti-inflammatory analgesic with CB(1) receptor antagonist and endocannabinoid modulating effects) was approved in Canada in 2005 for treatment of central neuropathic pain in multiple sclerosis, and in 2007 for intractable cancer pain. Numerous randomized clinical trials have demonstrated safety and efficacy for Sativex in central and peripheral neuropathic pain, rheumatoid arthritis and cancer pain. An Investigational New Drug application to conduct advanced clinical trials for cancer pain was approved by the US FDA in January 2006. Cannabinoid analgesics have generally been well tolerated in clinical trials with acceptable adverse event profiles. Their adjunctive addition to the pharmacological armamentarium for treatment of pain shows great promise.

Simultaneous quantification of Delta9-tetrahydrocannabinol, 11-hydroxy-Delta9-tetrahydrocannabinol, and 11-nor-Delta9-tetrahydrocannabinol-9-carboxylic acid in human plasma using two-dimensional gas chromatography, cryofocusing, and electron impact-mass spectrometry

A two-dimensional (2D) gas chromatography/electron impact-mass spectrometry (GC/EI-MS) method for simultaneous quantification of Delta(9)-tetrahydrocannabinol (THC), 11-hydroxy-Delta(9)-tetrahydrocannabinol (11-OH-THC), and 11-nor-Delta(9)-tetrahydrocannabinol-9-carboxylic acid (THCCOOH) in human plasma was developed and validated. The method employs 2D capillary GC and cryofocusing for enhanced resolution and sensitivity. THC, 11-OH-THC, and THCCOOH were extracted by precipitation with acetonitrile followed by solid-phase extraction. GC separation of trimethylsilyl derivatives of analytes was accomplished with two capillary columns in series coupled via a pneumatic Deans switch system. Detection and quantification were accomplished with a bench-top single quadrupole mass spectrometer operated in electron impact-selected ion monitoring mode. Limits of quantification (LOQ) were 0.125, 0.25 and 0.125 ng/mL for THC, 11-OH-THC, and THCCOOH, respectively. Accuracy ranged from 86.0 to 113.0% for all analytes. Intra- and inter-assay precision, as percent relative standard deviation, was less than 14.1% for THC, 11-OH-THC, and THCCOOH. The method was successfully applied to quantification of THC and its 11-OH-THC and THCCOOH metabolites in plasma specimens following controlled administration of THC.