The Effect of Route of Administration and Vehicle on the Pharmacokinetics of THC and CBD in Adult, Neonate, and Breastfed Sprague-Dawley Rats

Introduction: Basic pharmacokinetic (PK) and pharmacodynamic models of the phytocannabinoids Δ-9-tetrahydrocannabinol (THC) and cannabidiol (CBD) are critical for developing translational models of exposure and toxicity. The neonatal period is a particularly important time to study the effects of cannabinoids, yet there are few studies of cannabinoid PKs by different routes such as direct injection or breast milk ingestion. To study this question, we have developed a translationally relevant rodent model of perinatal cannabinoid administration by measuring plasma levels of THC and CBD after different routes and preparations of these drugs. Materials and Methods: Adult animals and pups were injected with THC or CBD either intraperitoneally or subcutaneously, and plasma was analyzed by liquid chromatography-tandem mass spectrometry to measure cannabinoid levels collected at specified intervals. We also tested the effect of preparation of the drug using an oil-based vehicle (sesame oil) and an aqueous vehicle (Tween). Finally, we measured the plasma levels of cannabinoids in neonatal pups that were transmitted through breast milk after intraperitoneal injection to nursing dams. Results: We observed differences in the PK profiles of cannabinoids in adults and neonatal pups that were dependent on the route of administration and type of vehicle. Cannabinoids prepared in aqueous vehicle, injected intraperitoneally, resulted in a high peak in plasma concentration, which rapidly decreased. In contrast, subcutaneous injections using sesame oil as a vehicle resulted in a slow rise and low plateau in plasma concentration. Intraperitoneal injections with sesame oil as a vehicle resulted in a slower rise compared with aqueous vehicle, but an earlier and higher peak compared with subcutaneous injection. Finally, the levels of THC and CBD that were similar to direct subcutaneous injections were measured in the plasma of pups nursing from intraperitoneally injected dams. Conclusions: The route of administration and the preparation of the drug have important and significant effects on the PK profiles of THC and CBD in rats. These results can be used to create different clinically relevant exposure paradigms in pups and adults, such as short high-dose exposure or a low-chronic exposure, each of which might have significant and varying effects on development.

E-cigarette vaping associated acute lung injury (EVALI): state of science and future research needs

"E-Cigarette (e-cig) Vaping-Associated Acute Lung Injury" (EVALI) has been linked to vitamin-E-acetate (VEA) and Δ-9-tetrahydrocannabinol (THC), due to their presence in patients' e-cigs and biological samples. Lacking standardized methodologies for patients' data collection and comprehensive physicochemical/toxicological studies using real-world-vapor exposures, very little data are available, thus the underlying pathophysiological mechanism of EVALI is still unknown. This review aims to provide a comprehensive and critical appraisal of existing literature on clinical/epidemiological features and physicochemical-toxicological characterization of vaping emissions associated with EVALI. The literature review of 161 medical case reports revealed that the predominant demographic pattern was healthy white male, adolescent, or young adult, vaping illicit/informal THC-containing e-cigs. The main histopathologic pattern consisted of diffuse alveolar damage with bilateral ground-glass-opacities at chest radiograph/CT, and increased number of macrophages or neutrophils and foamy-macrophages in the bronchoalveolar lavage. The chemical analysis of THC/VEA e-cig vapors showed a chemical difference between THC/VEA and the single THC or VEA. The chemical characterization of vapors from counterfeit THC-based e-cigs or in-house-prepared e-liquids using either cannabidiol (CBD), VEA, or medium-chain triglycerides (MCT), identified many toxicants, such as carbonyls, volatile organic compounds, terpenes, silicon compounds, hydrocarbons, heavy metals, pesticides and various industrial/manufacturing/automotive-related chemicals. There is very scarce published toxicological data on emissions from THC/VEA e-liquids. However, CBD, MCT, and VEA emissions exert varying degrees of cytotoxicity, inflammation, and lung damage, depending on puffing topography and cell line. Major knowledge gaps were identified, including the need for more systematic-standardized epidemiological surveys, comprehensive physicochemical characterization of real-world e-cig emissions, and mechanistic studies linking emission properties to specific toxicological outcomes.

Cannabis: A Toxin-Producing Plant with Potential Therapeutic Uses

For thousands of years, Cannabis sativa has been utilized as a medicine and for recreational and spiritual purposes. Phytocannabinoids are a family of compounds that are found in the cannabis plant, which is known for its psychotogenic and euphoric effects; the main psychotropic constituent of cannabis is Δ9-tetrahydrocannabinol (Δ9-THC). The pharmacological effects of cannabinoids are a result of interactions between those compounds and cannabinoid receptors, CB1 and CB2, located in many parts of the human body. Cannabis is used as a therapeutic agent for treating pain and emesis. Some cannabinoids are clinically applied for treating chronic pain, particularly cancer and multiple sclerosis-associated pain, for appetite stimulation and anti-emesis in HIV/AIDS and cancer patients, and for spasticity treatment in multiple sclerosis and epilepsy patients. Medical cannabis varies from recreational cannabis in the chemical content of THC and cannabidiol (CBD), modes of administration, and safety. Despite the therapeutic effects of cannabis, exposure to high concentrations of THC, the main compound that is responsible for most of the intoxicating effects experienced by users, could lead to psychological events and adverse effects that affect almost all body systems, such as neurological (dizziness, drowsiness, seizures, coma, and others), ophthalmological (mydriasis and conjunctival hyperemia), cardiovascular (tachycardia and arterial hypertension), and gastrointestinal (nausea, vomiting, and thirst), mainly associated with recreational use. Cannabis toxicity in children is more concerning and can cause serious adverse effects such as acute neurological symptoms (stupor), lethargy, seizures, and even coma. More countries are legalizing the commercial production and sale of cannabis for medicinal use, and some for recreational use as well. Liberalization of cannabis laws has led to increased incidence of toxicity, hyperemesis syndrome, lung disease cardiovascular disease, reduced fertility, tolerance, and dependence with chronic prolonged use. This review focuses on the potential therapeutic effects of cannabis and cannabinoids, as well as the acute and chronic toxic effects of cannabis use on various body systems.