Tetrahydrocannabinol (THC) is a cannabinoid found in cannabis. It is the principal psychoactive constituent of cannabis and one of at least 113 total cannabinoids identified on the plant. Its chemical formula C21H30O2 includes compounds, the term THC usually refers to the delta-9-THC isomer with chemical name (−)-trans-Δ9-tetrahydrocannabinol. It is a colorless oil.
An antiemetic is a drug that is effective against vomiting and nausea. Antiemetics are typically used to treat motion sickness and the side effects of opioid analgesics, general anaesthetics, and chemotherapy directed against cancer. They may be used for severe cases of gastroenteritis, especially if the patient is dehydrated.
Cannabinoids are several structural classes of compounds found in the cannabis plant primarily and most animal organisms or as synthetic compounds. The most notable cannabinoid is the phytocannabinoid tetrahydrocannabinol (THC) (delta-9-THC), the primary psychoactive compound in cannabis. Cannabidiol (CBD) is also a major constituent of temperate cannabis plants and a minor constituent in tropical varieties. At least 113 distinct phytocannabinoids have been isolated from cannabis, although only four have been demonstrated to have a biogenetic origin. It was reported in 2020 that phytocannabinoids can be found in other plants such as rhododendron, licorice and liverwort, and earlier in Echinacea.
Cannabinoid receptors, located throughout the body, are part of the endocannabinoid system of vertebrates– a class of cell membrane receptors in the G protein-coupled receptor superfamily. As is typical of G protein-coupled receptors, the cannabinoid receptors contain seven transmembrane spanning domains. Cannabinoid receptors are activated by three major groups of ligands:
Tetrahydrocannabivarin is a homologue of tetrahydrocannabinol (THC) having a propyl (3-carbon) side chain instead of pentyl (5-carbon), making it non-psychoactive in lower doses. It has been shown to exhibit neuroprotective activity, appetite suppression, glycemic control and reduced side effects compared to THC, making it a potential treatment for management of obesity and diabetes. THCV was studied by Roger Adams as early as 1942.
Nabilone, sold under the brand name Cesamet among others, is a synthetic cannabinoid with therapeutic use as an antiemetic and as an adjunct analgesic for neuropathic pain. It mimics tetrahydrocannabinol (THC), the primary psychoactive compound found naturally occurring in Cannabis.
WIN 55,212-2 is a chemical described as an aminoalkylindole derivative, which produces effects similar to those of cannabinoids such as tetrahydrocannabinol (THC) but has an entirely different chemical structure.
Nabitan (Nabutam, Benzopyranoperidine, SP-106, Abbott 40656) is a synthetic cannabinoid analog of dronabinol (Marinol) and dimethylheptylpyran. It exhibits antiemetic and analgesic effects, most likely by binding to and activating the CB1 and CB2 cannabinoid receptors, and reduced intraocular pressure in animal tests, making it potentially useful in the treatment of glaucoma.
G protein-coupled receptor 55 also known as GPR55 is a G protein-coupled receptor that in humans is encoded by the GPR55 gene.
Cannabinoid receptor 1 (CB1), is a G protein-coupled cannabinoid receptor that in humans is encoded by the CNR1 gene. The human CB1 receptor is expressed in the peripheral nervous system and central nervous system. It is activated by endogenous cannabinoids called endocannabinoids, a group of retrograde neurotransmitters that include lipids, such as anandamide and 2-arachidonoylglycerol (2-AG); plant phytocannabinoids, such as docosatetraenoylethanolamide found in wild daga, the compound THC which is an active constituent of the psychoactive drug cannabis; and synthetic analogs of THC. CB1 is antagonized by the phytocannabinoid tetrahydrocannabivarin (THCV).
JWH-073, a synthetic cannabinoid, is an analgesic chemical from the naphthoylindole family that acts as a full agonist at both the CB1 and CB2 cannabinoid receptors. It is somewhat selective for the CB1 subtype, with affinity at this subtype approximately 5× the affinity at CB2. The abbreviation JWH stands for John W. Huffman, one of the inventors of the compound.
Surinabant (SR147778) is a cannabinoid receptor type 1 antagonist developed by Sanofi-Aventis. It is being investigated as a potential treatment for nicotine addiction, to assist smoking cessation. It may also be developed as an anorectic drug to assist with weight loss, however there are already several CB1 antagonists or inverse agonists on the market or under development for this application, so surinabant is at present mainly being developed as an anti-smoking drug, with possible application in the treatment of other addictive disorders such as alcoholism. Other potential applications such as treatment of ADHD have also been proposed.
Nonabine (BRL-4664) is an experimental drug which is a synthetic THC analog. It was studied in the 1980s for the prevention of nausea and vomiting associated with cancer chemotherapy but was never marketed. It has strong antiemetic effects equivalent to those of chlorpromazine, and also produces some mild sedative effects, along with dry mouth and EEG changes typical of cannabinoid agonists, but with minimal changes in mood or perception, suggesting the abuse potential is likely to be low.
A cannabinoid receptor antagonist, also known simply as a cannabinoid antagonist or as an anticannabinoid, is a type of cannabinoidergic drug that binds to cannabinoid receptors (CBR) and prevents their activation by endocannabinoids. They include antagonists, inverse agonists, and antibodies of CBRs. The discovery of the endocannabinoid system led to the development of CB1 receptor antagonists. The first CBR inverse agonist, rimonabant, was described in 1994. Rimonabant blocks the CB1 receptor selectively and has been shown to decrease food intake and regulate body-weight gain. The prevalence of obesity worldwide is increasing dramatically and has a great impact on public health. The lack of efficient and well-tolerated drugs to cure obesity has led to an increased interest in research and development of CBR antagonists. Cannabidiol (CBD), a naturally occurring cannabinoid and a non-competitive CB1/CB2 receptor antagonist, as well as Δ9-tetrahydrocannabivarin (THCV), a naturally occurring cannabinoid, modulate the effects of THC via direct blockade of cannabinoid CB1 receptors, thus behaving like first-generation CB1 receptor inverse agonists, such as rimonabant. CBD is a very low-affinity CB1 ligand, that can nevertheless affect CB1 receptor activity in vivo in an indirect manner, while THCV is a high-affinity CB1 receptor ligand and potent antagonist in vitro and yet only occasionally produces effects in vivo resulting from CB1 receptor antagonism. THCV has also high affinity for CB2 receptors and signals as a partial agonist, differing from both CBD and rimonabant.
Synthetic cannabinoids are a class of designer drug molecules that bind to the same receptors to which cannabinoids in cannabis plants attach. These novel psychoactive substances should not be confused with synthetic phytocannabinoids or synthetic endocannabinoids from which they are in many aspects distinct.
Dronabinol (INN), also known under the trade names Marinol and Syndros, is a generic name for the molecule of delta-9-tetrahydrocannabinol in the pharmaceutical context. It has indications as an appetite stimulant, antiemetic, and sleep apnea reliever and is approved by the FDA as safe and effective for HIV/AIDS-induced anorexia and chemotherapy-induced nausea and vomiting only.
AM-2233 is a drug that acts as a highly potent full agonist for the cannabinoid receptors, with a Ki of 1.8 nM at CB1 and 2.2 nM at CB2 as the active (R) enantiomer. It was developed as a selective radioligand for the cannabinoid receptors and has been used as its 131I derivative for mapping the distribution of the CB1 receptor in the brain. AM-2233 was found to fully substitute for THC in rats, with a potency lower than that of JWH-018 but higher than WIN 55,212-2.
Tetrahydrocannabiphorol (THCP) is a potent phytocannabinoid, a CB1 and CB2 agonist which was known as a synthetic homologue of THC, but for the first time in 2019 was isolated as a natural product in trace amounts from Cannabis sativa. It is structurally similar to Δ9-THC, the main active component of cannabis, but with the pentyl side chain extended to heptyl. Since it has a longer side chain, its cannabinoid effects are "far higher than Δ9-THC itself." Tetrahydrocannabiphorol has a reported binding affinity of 1.2 nM at CB1, approximately 33 times that of Δ9-THC (40 nM at CB1).
Δ-8-tetrahydrocannabinol is a psychoactive cannabinoid found in the Cannabis plant. It is an isomer of delta-9-tetrahydrocannabinol, the compound commonly known as THC, with which it co-occurs in hemp; natural quantities of ∆8-THC found in hemp are low.
CP 42,096 is an analgesic drug which acts as a cannabinoid agonist. It was developed by Pfizer in the 1980s as part of the research that led to the development of levonantradol, and is more potent than THC but less potent than newer compounds such as CP 55,244.
