Background Opioids continue to be widely prescribed for chronic noncancer pain, despite the awareness that opioids provide only short-time pain relief, lead to dose accumulation, have numerous... Show moreBackground Opioids continue to be widely prescribed for chronic noncancer pain, despite the awareness that opioids provide only short-time pain relief, lead to dose accumulation, have numerous adverse effects, and are difficult to wean. As an alternative, we previously showed advantages of using pharmaceutical-grade cannabis in a population of chronic pain patients with fibromyalgia. It remains unknown whether combining an opioid with pharmaceutical-grade cannabis has advantages, such as fewer side effects from lesser opioid consumption in chronic pain.Methods Trial design: a single-center, randomized, three-arm, open-label, exploratory trial.Trial population: 60 patients with fibromyalgia according to the 2010 definition of the American College of Rheumatologists.Intervention: Patients will be randomized to receive up to 4 daily 5 mg oral oxycodone sustained release (SR) tablet, up to 5 times 150 mg inhaled cannabis (Bediol (R), containing 6.3% delta(9)-tetrahydrocannabinol and 8% cannabidiol), or the combination of both treatments. Treatment is aimed at self-titration with the daily maximum doses given. Treatment will continue for 6 weeks, after which there is a 6-week follow-up period.Main trial endpoint: The number of side effects observed during the course of treatment using a composite adverse effect score that includes the following 10 symptoms: dizziness (when getting up), sleepiness, insomnia, headache, nausea, vomiting, constipation, drug high, hallucinations, and paranoia.Secondary and tertiary endpoints include pain relief and number of oxycodone doses and cannabis inhalations.Discussion The trial is designed to determine whether self-titration of oxycodone and cannabis will reduce side effects in chronic pain patients with fibromyalgia. Show less
Cannabis produces a broad range of acute, dose-dependent psychotropic effects. Only a limited number of neuroimaging studies have mapped these effects by examining the impact of cannabis on resting... Show moreCannabis produces a broad range of acute, dose-dependent psychotropic effects. Only a limited number of neuroimaging studies have mapped these effects by examining the impact of cannabis on resting state brain neurophysiology. Moreover, how genetic variation influences the acute effects of cannabis on resting state brain function is unknown. Here we investigated the acute effects of Delta 9-tetrahydrocannabinol (THC), the main psychoactive constituent of cannabis, on resting state brain neurophysiology, and their modulation by catechol-methyl-transferase (COMT) Val158Met genotype. Thirty-nine healthy volunteers participated in a pharmacological MRI study, where we applied Arterial Spin Labelling (ASL) to measure perfusion and functional MRI to assess resting state connectivity. THC increased perfusion in bilateral insula, medial superior frontal cortex, and left middle orbital frontal gyrus. This latter brain area showed significantly decreased connectivity with the precuneus after THC administration. THC effects on perfusion in the left insula were significantly related to subjective changes in perception and relaxation. These findings indicate that THC enhances metabolism and thus neural activity in the salience network. Furthermore, results suggest that recruitment of brain areas within this network is involved in the acute effects of THC. Resting state perfusion was modulated by COMT genotype, indicated by a significant interaction effect between drug and genotype on perfusion in the executive network, with increased perfusion after THC in Val/Met heterozygotes only. This finding suggests that prefrontal dopamine levels are involved in the susceptibility to acute effects of cannabis. (C) 2019 Elsevier B.V. and ECNP. All rights reserved. Show less
Donk, T. van de; Niesters, M.; Kowal, M.A.; Olofsen, E.; Dahan, A.; Velzen, M. van 2019
AbstractBackgroundNeuroimaging studies have demonstrated gray matter (GM) volume abnormalities in substance users. While the majority of substance users are polysubstance users, very little is... Show moreAbstractBackgroundNeuroimaging studies have demonstrated gray matter (GM) volume abnormalities in substance users. While the majority of substance users are polysubstance users, very little is known about the relation between GM volume abnormalities and polysubstance use.MethodsIn this study we assessed the relation between GM volume, and the use of alcohol, tobacco, cocaine and cannabis as well as the total number of substances used, in a sample of 169 males: 15 non-substance users, 89 moderate drinkers, 27 moderate drinkers who also smoke tobacco, 13 moderate drinkers who also smoke tobacco and use cocaine, 10 heavy drinkers who smoke tobacco and use cocaine and 15 heavy drinkers who smoke tobacco, cannabis and use cocaine.ResultsRegression analyses showed that there was a negative relation between the number of substances used and volume of the dorsal medial prefrontal cortex (mPFC) and the ventral mPFC. Without controlling for the use of other substances, the volume of the dorsal mPFC was negatively associated with the use of alcohol, tobacco, and cocaine. After controlling for the use of other substances, a negative relation was found between tobacco and cocaine and volume of the thalami and ventrolateral PFC, respectively.ConclusionThese findings indicate that mPFC alterations may not be substance-specific, but rather related to the number of substances used, whereas, thalamic and ventrolateral PFC pathology is specifically associated with tobacco and cocaine use, respectively. These findings are important, as the differential alterations in GM volume may underlie different cognitive deficits associated with substance use disorders. Show less
Cannabis and alcohol are believed to have widespread effects on the brain. Although adolescents are at increased risk for substance use, the adolescent brain may also be particularly vulnerable to... Show moreCannabis and alcohol are believed to have widespread effects on the brain. Although adolescents are at increased risk for substance use, the adolescent brain may also be particularly vulnerable to the effects of drug exposure due to its rapid maturation. Here, we examined the association between cannabis and alcohol use duration and resting-state functional connectivity in a large sample of male juvenile delinquents.The present sample was drawn from the Southwest Advanced Neuroimaging Cohort, Youth sample, and from a youth detention facility in Wisconsin. All participants were scanned at the maximum-security facilities using The Mind Research Network’s 1.5T Avanto SQ Mobile MRI scanner. Information on cannabis and alcohol regular use duration was collected using self-report. Resting-state networks were computed using group independent component analysis in 201 participants. Associations with cannabis and alcohol use were assessed using Mancova analyses controlling for age, IQ, smoking and psychopathy scores in the complete case sample of 180 male juvenile delinquents.No associations between alcohol or cannabis use and network spatial maps were found. Longer cannabis use was associated with decreased low frequency power of the default mode network, the executive control networks (ECNs), and several sensory networks, and with decreased functional network connectivity. Duration of alcohol use was associated with decreased low frequency power of the right frontoparietal network, salience network, dorsal attention network, and several sensory networks.Our findings suggest that adolescent cannabis and alcohol use are associated with widespread differences in resting-state time course power spectra, which may persist even after abstinence. Show less
Kowal, M.A.; Hazekamp, A.; Colzato, L.S.; Steenbergen, H. van; Wee, N.J.A. van der; Durieux, J.; ... ; Hommel, B. 2015
Although cannabis is especially known for its recreational use as a __soft drug__, its potential therapeutic properties have been recognized for hundreds of years. Since the isolation of THC from... Show moreAlthough cannabis is especially known for its recreational use as a __soft drug__, its potential therapeutic properties have been recognized for hundreds of years. Since the isolation of THC from Cannabis sativa L, the discovery of cannabinoid receptors and their natural ligands (endocannabinoids) the interest in the development of novel cannabinoids as medicine is accelerating. This thesis describes useful cannabis-biomarkers and the clinical pharmacology of some cannabinoid agonists and antagonists in early phase drug development. This includes a novel mode of pure intrapulmonary THC administration that can be used as a benchmark for novel CB1/CB2-agonists, or to demonstrate inhibitory activity of CB1-antagonists. In addition, the pharmacodynamics and pharmacokinetics of two novel CB1/CB2 agonists are evaluated and compared with the pharmacodynamic effect profile of THC. The clinical trials carried out for this research were performed at the Centre for Human Drug Research, Leiden, The Netherlands. Show less
The cannabis plant (Cannabis sativa L.) has a long history as a recreational drug, but also as part of traditional medicine in many cultures. Nowadays, it is used by a large number of patients... Show moreThe cannabis plant (Cannabis sativa L.) has a long history as a recreational drug, but also as part of traditional medicine in many cultures. Nowadays, it is used by a large number of patients worldwide, to ameliorate the symptoms of diseases varying from cancer and AIDS to multiple sclerosis and migraine. The discovery of cannabinoid-receptors and the endocannabinoid system have opened up a new and exciting field of research. But despite the pharmaceutical potential of cannabis, its classification as a narcotic drug has prevented the successful development of cannabis into modern medicine. Although a huge number of scientific papers has been published on cannabis, there is currently no scientific consensus on the usefulness of medicinal cannabis. In 2004, The Netherlands became the first country to make herbal cannabis available as a prescription drug. The phytochemical research presented in this thesis has been possible because of the availability of these high-grade cannabis plants. This thesis has a specific focus on the cannabinoids and on analytical problems that currently obstruct advanced study of the cannabis plant. Furthermore, it deals with much needed methods for quality control and with administration forms of medicinal cannabis. In general, it may be considered a general guidebook, covering all the basic phytochemical aspects of medicinal cannabis. Show less
