Cannabis Effects on Electroencephalography

Overview

Background: Tetrahydrocannabinol (THC) is a partial CB1/CB2 agonist and causes its pharmacological effects by binding to cannabinoid receptors. CB1 receptors are predominantly located in the brain (highest densities at hippocampus, cerebellum and the striatum) and at low levels in the brainstem. CB2 receptors are predominantly in the spleen and in hematopoietic cells. THC is highly lipophilic and is readily absorbed and distributed to the brain and other organs. Most of the neuropsychological studies carried out so far show that the mainly affected neurocognitive functions in cannabis users are: memory, attention, psychomotor capacity, speed of information processing and alterations of executive functions (resistance to interference, planning capacity, decision-making, verbal fluency and working memory). These effects are dose-dependent. Hypothesis: Functional CB1 receptor activation by the THC contained in the cannabis flos will induce dose-dependent effects on EEG, physiological functions and behavior: 1. EEG alterations. 2. Increase in cannabis subjective effects. 3. Increase in heart rate. 4. Increase in psychopathology scale Psychotomimetic State Inventory (PSI) score. 5. Increase in plasma cortisol concentrations. Objectives: Main pharmacodynamic objective: To assess the effects of Cannabis flos on electroencephalography (EEG) in healthy recreational cannabis users. Secondary pharmacodynamic objectives: (i) To assess the effects of Cannabis flos on: cannabis subjective effects, heart rate and psychopathology scale; (ii) To establish the pharmacokinetic/pharmacodynamic relationships between THC plasma concentrations and pharmacodynamic endpoints. Safety and tolerability objectives: To assess the safety and tolerability of THC in these subjects. Methods: Phase I, prospective, monocentric, double-blind, randomized, placebo-controlled, parallel group study to assess the THC effects on EEG neural oscillations in 16 healthy subjects with recreational cannabis use.

Subjects will be randomly assigned in a 2:1 ratio to either Arm A (Cannabis) or Arm B (Cannabis placebo). The subjects, Investigators and designees involved in the conduct of the study will be blinded to the identity of the treatment administered during the study. In the active group (Arm A) subjects will be administered four single doses of 20 mg THC over 3 days, equivalent to 285.7 μg/kg. This dose is considered to be sufficient for eliciting the psychoactive effects of THC (\> 5 ng/mL in plasma) and modify EEG, avoiding subjects to be too much behaviorally impaired. THC will be administered in the form of medical cannabis (Bedrocan®) inhaled by intrapulmonary route. It is featured in flos form (Cannabis sativa dried female flower) containing THC 22% and cannabidiol (CBD) \<1%. A vaporization system (Mighty® Medic device) will be used for cannabis administration. Through this system, the final inhalation of THC is comparable to that of smoking cannabis while reducing the inhalation of toxic and irritating substances generated in the combustion of herbs.