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. Although the chemical formula for THC (C21H30O2) describes multiple isomers, 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.
Medical cannabis, medicinal cannabis or medical marijuana (MMJ), refers to cannabis products and cannabinoid molecules that are prescribed by physicians for their patients. The use of cannabis as medicine has a long history, but has not been as rigorously tested as other medicinal plants due to legal and governmental restrictions, resulting in limited clinical research to define the safety and efficacy of using cannabis to treat diseases.
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.
Fibromyalgia is a medical syndrome that causes chronic widespread pain, accompanied by fatigue, awakening unrefreshed, and cognitive symptoms. Other symptoms can include headaches, lower abdominal pain or cramps, and depression. People with fibromyalgia can also experience insomnia and general hypersensitivity. The cause of fibromyalgia is unknown, but is believed to involve a combination of genetic and environmental factors. Environmental factors may include psychological stress, trauma, and some infections. Since the pain appears to result from processes in the central nervous system, the condition is referred to as a "central sensitization syndrome".
Metoclopramide is a medication used for stomach and esophageal problems. It is commonly used to treat and prevent nausea and vomiting, to help with emptying of the stomach in people with delayed stomach emptying, and to help with gastroesophageal reflux disease. It is also used to treat migraine headaches.
Granisetron is a serotonin 5-HT3 receptor antagonist used as an antiemetic to treat nausea and vomiting following chemotherapy and radiotherapy. Its main effect is to reduce the activity of the vagus nerve, which is a nerve that activates the vomiting center in the medulla oblongata. It does not have much effect on vomiting due to motion sickness. This drug does not have any effect on dopamine receptors or muscarinic receptors.
Opioids are a class of drugs that derive from, or mimic, natural substances found in the opium poppy plant. Opioids work in the brain to produce a variety of effects, including pain relief. As a class of substances, they act on opioid receptors to produce morphine-like effects.
Duloxetine, sold under the brand name Cymbalta among others, is a medication used to treat major depressive disorder, generalized anxiety disorder, obsessive-compulsive disorder, fibromyalgia, neuropathic pain and central sensitization. It is taken by mouth.
Cannabidiol (CBD) is a phytocannabinoid, one of 113 identified cannabinoids in cannabis plants, along with tetrahydrocannabinol (THC), and accounts for up to 40% of the plant's extract. Medically, it is an anticonvulsant used to treat multiple forms of epilepsy. It was discovered in 1940 and, as of 2022, clinical research on CBD included studies related to the treatment of anxiety, addiction, psychosis, movement disorders, and pain, but there is insufficient high-quality evidence that CBD is effective for these conditions. CBD is sold as an herbal dietary supplement and promoted with yet unproven claims of particular therapeutic effects.
Nabiximols (USAN) sold under the brand name Sativex, is a specific Cannabis extract that was approved in 2010 as a botanical drug in the United Kingdom. Nabiximols is sold as a mouth spray intended to alleviate neuropathic pain, spasticity, overactive bladder, and other symptoms of multiple sclerosis; it was developed by the UK company GW Pharmaceuticals. In 2019, it was proposed that following application of the spray, nabiximols is washed away from the oral mucosa by the saliva flow and ingested into the stomach, with subsequent absorption from the gastro-intestinal tract. Nabiximols is a combination drug standardized in composition, formulation, and dose. Its principal active components are the cannabinoids: tetrahydrocannabinol (THC) and cannabidiol (CBD). Each spray delivers a dose of 2.7 mg THC and 2.5 mg CBD.
Levonantradol (CP 50,556-1) is a synthetic cannabinoid analog of dronabinol (Marinol) developed by Pfizer in the 1980s. It is around 30 times more potent than THC, and exhibits antiemetic and analgesic effects via activation of CB1 and CB2 cannabinoid receptors. Levonantradol is not currently used in medicine as dronabinol or nabilone are felt to be more useful for most conditions, however it is widely used in research into the potential therapeutic applications of cannabinoids.
Low-dose naltrexone (LDN) refers to daily naltrexone dosages that are roughly one-tenth of the standard opioid addiction treatment dosage. Most published research suggests a daily dosage of 4.5 mg, but this can vary by a few milligrams. Low-dose naltrexone has been studied for the treatment of multiple chronic pain disorders including fibromyalgia, multiple sclerosis, Crohn’s disease, and complex regional pain syndrome.
Lubiprostone, sold under the brand name Amitiza among others, is a medication used in the management of chronic idiopathic constipation, predominantly irritable bowel syndrome-associated constipation in women and opioid-induced constipation. The drug is owned by Mallinckrodt and is marketed by Takeda Pharmaceutical Company.
Metopimazine, sold under the brand names Vogalen and Vogalene, is an antiemetic of the phenothiazine group which is used to treat nausea and vomiting. It is marketed in Europe, Canada, and South America. As of August 2020, metopimazine has been repurposed and is additionally under development for use in the United States for the treatment of gastroparesis.
Nausea is a diffuse sensation of unease and discomfort, sometimes perceived as an urge to vomit. It can be a debilitating symptom if prolonged and has been described as placing discomfort on the chest, abdomen, or back of the throat.
Dronabinol, sold under the brand names Marinol and Syndros, is the generic name for the molecule of delta-9-tetrahydrocannabinol (THC) in the pharmaceutical context. It has indications as an appetite stimulant, antiemetic, and sleep apnea reliever and is approved by the U.S. FDA as safe and effective for HIV/AIDS-induced anorexia and chemotherapy-induced nausea and vomiting.
Cannabinoid hyperemesis syndrome (CHS) is recurrent nausea, vomiting, and cramping abdominal pain that can occur due to prolonged, high-dose cannabis use. Complications are related to persistent vomiting and dehydration which may lead to kidney failure and electrolyte problems.
Chemotherapy-induced nausea and vomiting (CINV) is a common side-effect of many cancer treatments. Nausea and vomiting are two of the most feared cancer treatment-related side effects for cancer patients and their families. In 1983, Coates et al. found that patients receiving chemotherapy ranked nausea and vomiting as the first and second most severe side effects, respectively. Up to 20% of patients receiving highly emetogenic agents in this era postponed, or even refused, potentially curative treatments. Since the 1990s, several novel classes of antiemetics have been developed and commercialized, becoming a nearly universal standard in chemotherapy regimens, and helping to better manage these symptoms in a large portion of patients. Efficient mediation of these unpleasant and sometimes debilitating symptoms results in increased quality of life for the patient, and better overall health of the patient, and, due to better patient tolerance, more effective treatment cycles.
Cancer and nausea are associated in about fifty percent of people affected by cancer. This may be as a result of the cancer itself, or as an effect of the treatment such as chemotherapy, radiation therapy, or other medication such as opiates used for pain relief. About 70–80% of people undergoing chemotherapy experience nausea or vomiting. Nausea and vomiting may also occur in people not receiving treatment, often as a result of the disease involving the gastrointestinal tract, electrolyte imbalance, or as a result of anxiety. Nausea and vomiting may be experienced as the most unpleasant side effects of cytotoxic drugs and may result in patients delaying or refusing further radiotherapy or chemotherapy.
