Abstract Purpose: Aqueous deficiency dry eye (ADDE) is a chronic condition affecting millions, with symptoms ranging from a dry itchiness to blurred vision and accompanied by an increased risk of eye infections. ADDE typically arises from disorders of the lacrimal gland that produces tears necessary for eye lubrication. Cannabis users frequently report dry eye, but the basis for this is unknown. If the effects occur via the endogenous cannabinoid signaling system, then this may represent a novel mechanism for the regulation of tearing. Methods: We examined expression of cannabinoid CB1 receptors in the lacrimal gland using immunohistochemistry, Western blotting, and PCR and tested tetrahydrocannabinol (THC) regulation...

Abstract Objective To determine the benefit of a tetrahydrocannabinol (THC)-rich cannabis oil on symptoms and quality of life of fibromyalgia patients. Methods A double-blind, randomized, placebo-controlled clinical trial was conducted for eight weeks to determine the benefit of a THC-rich cannabis oil (24.44 mg/mL of THC and 0.51 mg/mL of cannabidiol [CBD]) on symptoms and quality of life of 17 women with fibromyalgia, residents of a neighborhood with a low socioeconomic profile and a high incidence of violence in the city of Florianopolis, Brazil. The initial dose was one drop (∼1.22 mg of THC and 0.02 mg of CBD) a day with subsequent increases according to symptoms. The...

Abstract The endocannabinoid system serves a critical role in homeostatic regulation through its influence on processes underlying appetite, pain, reward, and stress, and cannabis has long been used for the related modulatory effects it provides through tetrahydrocannabinol (THC). We investigated how THC exposure relates to tissue microstructure of the cerebral cortex and subcortical nuclei using computational modeling of diffusion magnetic resonance imaging data in a large cohort of young adults from the Human Connectome Project. We report strong associations between biospecimen-defined THC exposure and microstructure parameters in discrete gray matter brain areas, including frontoinsular cortex, ventromedial prefrontal cortex, and the lateral amygdala subfields, with...

Abstract The neurobiological mechanisms underlying the association between cannabis use and acute or long-lasting psychosis are not completely understood. While some evidence suggests altered striatal dopamine may underlie the association, direct evidence that cannabis use affects either acute or chronic striatal dopamine is inconclusive. In contrast, pre-clinical research suggests that cannabis may affect dopamine via modulation of glutamate signaling. A double-blind, randomized, placebo-controlled, crossover design was used to investigate whether altered striatal glutamate, as measured using proton magnetic resonance spectroscopy, underlies the acute psychotomimetic effects of intravenously administered delta-9-tetrahydrocannabinol (Δ9-THC; 1.19 mg/2 ml), the key psychoactive ingredient in cannabis, in a set of 16 healthy participants...

Highlights Control of chemotherapy-induced nausea and vomiting is inadequate. This phase II crossover randomised controlled trial compared oral cannabis extract or placebo together with guideline-recommended antiemetics. There was a significant improvement in the control of chemotherapy-induced nausea and vomiting. Although there were additional side-effects, most participants preferred cannabis extract to placebo. Based on these positive results, the definitive parallel phase III trial component continues to recruit. Background This multicentre, randomised, double-blinded, placebo-controlled, phase II/III trial aimed to evaluate an oral THC:CBD (tetrahydrocannabinol:cannabidiol) cannabis extract for prevention of refractory chemotherapy-induced nausea and vomiting (CINV). Here we report the phase II component results. Patients and methods...

Abstract With the increasing prevalence of legal cannabis use and availability, there is an urgent need to identify cognitive impairments related to its use. It is widely believed that cannabis, or its main psychoactive component Δ9-tetrahydrocannabinol (THC), impairs working memory, i.e., the ability to temporarily hold information in mind. However, our review of the literature yielded surprisingly little empirical support for an effect of THC or cannabis on working memory. We thus conducted a study with three main goals: (1) quantify the effect of THC on visual working memory in a well-powered sample, (2) test the potential role of cognitive effects (mind wandering and...

Please use this link to access this publication. Key Points Question  What is the magnitude and duration of driving impairment following vaporization of cannabis containing varying concentrations of Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD)? Findings  In this crossover clinical trial that included 26 healthy participants who underwent on-road driving tests, the standard deviation of lateral position (SDLP, a measure of lane weaving, swerving, and overcorrecting) at 40 to 100 minutes following vaporized consumption was 18.21 cm for CBD-dominant cannabis, 20.59 cm for THC-dominant cannabis, 21.09 cm for THC/CBD-equivalent cannabis, and was 18.26 cm for placebo. At 240 to 300 minutes, the SDLP was 19.03 cm for CBD-dominant...

Abstract Tetrahydrocannabinol (THC) is the primary psychoactive ingredient in cannabis. While the safety of THC and cannabis has been extrapolated from millennia of recreational use, medical marijuana programs have increased exposure among medically complex individuals with comorbid conditions and many co-prescribed medications. Thus, THC should be recognized as a pharmacologically complex compound with potential for drug–drug interactions and adverse drug events. This review summarizes potential adverse drug events related to THC when combined with other medications. Metabolic drug–drug interactions are primarily due to THC conversion by CYP3A4 and CYP2C9, which can be impacted by several common medications. Further, CYP2C9 polymorphisms are highly prevalent in...

Abstract   Background: This study is based on the premise that while consumption of cannabis has increased for medicinal and recreational purposes there has also been an increase in adverse events seemingly associated with cannabis usage.   Objective: This study was designed to investigate the effect of different concentrations of Delta-9-Tetrahydrocannabinol (THC) and Cannabidiol (CBD) separately and in combination on blood flow.   Method: Forty male Sprague-Dawley rats were randomly divided into eight groups consisting of five rats each. Six of the test groups received different concentrations of THC and CBD (1 and 2 mg/kg body weight) respectively, while the seventh group received an extract with a...

Abstract Multiple sclerosis (MS) is the most common cause of non-traumatic neurological disability in young adults. It has effects at different levels: physical, emotional, psychological, cognitive and social, with a great variety of signs and symptoms. In particular, spasticity contributes to reducing the motor performance of patients with MS, causing pain, reduction in distance walked and limitations in social life. We present the case of a 39-year-old woman with MS. She was treated with delta-9-tetrahydrocannabinol/cannabidiol and the outcome was assessed with the International Classification of Functioning Disability and Health core set framework. LEARNING POINTS The clinical presentation of multiple sclerosis (MS) is heterogeneous but...