Cannabidiol

Cannabidiol (CBD)

CBD (cannabidiol)

Breast feeding; Lactation; Milk, Human; Anticonvulsants; Cannabinoids

FDA approved drugs -> Active ingredient

EMA approved medicines: Human medicine (Orphan designations)

FDA approved drugs -> Active ingredient

Pharmaceuticals

Warning

H302 (41.7%): Harmful if swallowed [Warning Acute toxicity, oral]

P203, P261, P264, P270, P271, P280, P301+P317, P304+P340, P317, P318, P330, P405, and P501 (click each P-code to see the statement)

Aggregated GHS information provided per 36 reports by companies from 14 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

In prelicensure studies, serum aminotransferase elevations arose during cannabidiol therapy for epilepsy in 34% to 47% of patients compared to 18% of controls who were receiving other anticonvulsant medications. Elevations above 3 times ULN occurred in 13% of cannabidiol treated compared to 1% on placebo. ALT and AST elevations were more frequent with higher doses and were particularly common (and sometimes delayed) in patients who were receiving valproate and clobazam. The aminotransferase elevations typically arose within the first two months of treatment and were transient, mild-to-moderate in severity, and not associated with symptoms or jaundice. There have been no convincing reports of clinically apparent liver injury with jaundice attributable to prescription forms of cannabidiol, but it has had very limited general use.

Drug Induced Liver Injury Rank (DILIrank 2.0)

Cannabidiol

Ambiguous-DILI-concern

3

Warnings & precautions

DOI:10.1016/j.drudis.2016.02.015

N - Nervous system

QN - Nervous system

Although the exact mechanism and magnitude of effects of THC and CBD are not fully understood, CBD has been shown to have analgesic, anticonvulsant, muscle relaxant, anxiolytic, neuroprotective, anti-oxidant, and anti-psychotic activity. This wide variety of effects is likely due to it's complex pharmacological mechanisms. In addition to binding to CB1 and CB2 receptors of the endocannabinoid system, there is evidence that CBD activates 5-HT1A serotonergic and TRPV1–2 vanilloid receptors, antagonizes alpha-1 adrenergic and µ-opioid receptors, inhibits synaptosomal uptake of noradrenaline, dopamine, serotonin and gaminobutyric acid and cellular uptake of anandamide, acts on mitochondria Ca2 stores, blocks low-voltage-activated (T-type) Ca2 channels, stimulates activity of the inhibitory glycine-receptor, and inhibits activity of fatty amide hydrolase (FAAH).

The exact mechanism of action of CBD and THC is not currently fully understood. However, it is known that CBD acts on cannabinoid (CB) receptors of the endocannabinoid system, which are found in numerous areas of the body, including the peripheral and central nervous systems, including the brain. The endocannabinoid system regulates many physiological responses of the body including pain, memory, appetite, and mood. More specifically, CB1 receptors can be found within the pain pathways of the brain and spinal cord where they may affect CBD-induced analgesia and anxiolysis, and CB2 receptors have an effect on immune cells, where they may affect CBD-induced anti-inflammatory processes. CBD has been shown to act as a negative allosteric modulator of the cannabinoid CB1 receptor, the most abundant G-Protein Coupled Receptor (GPCR) in the body. Allosteric regulation of a receptor is achieved through the modulation of the activity of a receptor on a functionally distinct site from the agonist or antagonist binding site. The negative allosteric modulatory effects of CBD are therapeutically important as direct agonists are limited by their psychomimetic effects while direct antagonists are limited by their depressant effects.

THC and CBD are metabolized in the liver by a number of cytochrome P450 isoenzymes, including CYP2C9, CYP2C19, CYP2D6 and CYP3A4. They may be stored for as long as four weeks in the fatty tissues from which they are slowly released at sub-therapeutic levels back into the blood stream and metabolized via the renal and biliary systems. The main primary metabolite of CBD is 7-hydroxy-cannabidiol.

19GBJ60SN5

CANNABIDIOL

Chemical Structure [CS] - Cannabinoids

Mechanisms of Action [MoA] - Cytochrome P450 2C8 Inhibitors

Mechanisms of Action [MoA] - Cytochrome P450 2C9 Inhibitors

Mechanisms of Action [MoA] - Cytochrome P450 2C19 Inhibitors

Following a single buccal administration, maximum plasma concentrations of both CBD and THC typically occur within two to four hours. When administered buccally, blood levels of THC and other cannabinoids are lower compared with inhalation of smoked cannabis. The resultant concentrations in the blood are lower than those obtained by inhaling the same dose because absorption is slower, redistribution into fatty tissues is rapid and additionally some of the THC undergoes hepatic first pass metabolism to 11-OH-THC, a psycho-active metabolite. The CBD component of sublingual Sativex was found to have a Tmax of 1.63hr and a Cmax of 2.50ng/mL, while buccal Sativex was found to have a Tmax of 2.80hr and a Cmax of 3.02ng/mL.

Elimination from plasma is bi-exponential with an initial half-life of one to two hours. The terminal elimination half-lives are of the order of 24 to 36 hours or longer. Sativex is excreted in the urine and faeces.

Cannabinoids are distributed throughout the body; they are highly lipid soluble and accumulate in fatty tissue. The release of cannabinoids from fatty tissue is responsible for the prolonged terminal elimination half-life.