The fundamentals of the science of medicinal cannabis can be tough to comprehend. Complex is an apt adjective to describe the process by which plant-based cannabinoids make their way into the human body to compete for receptor space with the endogenous system. For that reason, the informational component to understanding bedro-oils has been broken down into four parts, with inhalation – perhaps the most obvious theme – concluding the series.
As a preface to this final instalment on the anatomy of absorption, it should be noted the effects of use are the same whether cannabis is vaporized or smoked, though vaping, as it is commonly known, is recommended. The one major difference between the two is that carbon monoxide is produced by combustion, which causes a light-headed feeling historically misinterpreted as rapid onset when smoking.
The core of any inhaled medication is the movement of compounds through the porous membrane tissue in two areas of the lungs known as the alveolar region and terminal bronchioles. This process is contingent on three factors: conditions prior to reaching the lung tissue; competing factors within the lung tissue; and conditions once compounds have passed through the lung tissue. The factors affecting absorption of cannabinoids are no different than any inhaled substance, however the degree to which those factors influence the absorption will vary for any substance.
Before reaching the lung tissue, cannabinoids are first subject to variability in how they are deposited, how they dissolve and how much mucous clearance occurs. When a compound is inhaled, the makeup of the substance will influence the variability of the impact. If the substance being inhaled is in a soluble form, it will rapidly deposit and dissolve into the fluid on the surface of the lung tissue. Conversely, less soluble particulate will maintain its composition longer and may be subject to mucous clearance precipitated by coughing.
Once the cannabinoids have made way into the lung tissue, the metabolism of the lung’s cells will begin to impact how much, say THC or CBD, enters into the system. It’s here one of the body’s detoxification mechanisms plays a significant role. In the lungs, enzymes categorized as cytochrome P450 (CYP) are used to clear and, in some cases, activate compounds.
The last stage of the inhalation process is systemic absorption, which means the entry of cannabinoids into the bloodstream. It may be helpful to liken this final step to merging onto a highway, as there are three different paths, or transport mechanisms, that can be taken to get there.
Passive diffusion is a simple merger from a packed on-ramp (area of high concentration) onto an empty highway (area of low concentration). Think of drug transporters as bus lanes on a busy highway, capable of connecting compounds that otherwise wouldn’t be able to enter the bloodstream. Lastly, vesicle-mediated transport is an express route that carries compounds into the bloodstream when passive diffusion cannot, or the standard highway is closed.
As evidenced, absorption of cannabinoids through the lungs – similar to the general science behind this new area of research – is a complex process. Through absorption and inhalation, and by way of the endocannabinoid system, do cannabinoids take a complex course in the body. By examining the three in thorough detail, it is hoped the tenets of medicinal cannabis have also been explored.