Cannabis is an effective treatment for managing nausea in cancer patients. Using data from the Releaf App, UNM researchers identified the types of common medicinal cannabis products that are most effective for nausea and which product characteristics were associated with greater symptom relief.
Medicinal Cannabis has not been shown to interact with other anti-nausea medications. However, caution should be taken in patients with hepatic impairment.
Endocannabinoid System
The ECS is a biological system that controls several central physiological processes, including pain, stress, sleep, neurodevelopment and metabolism. It consists of a network of endogenous cannabinoid (EC) transmitters synthesizing and degrading enzymes and specific transmembrane EC receptor proteins. The brain’s ECS regulates synaptic plasticity in both excitatory and inhibitory pathways. Neuronal depolarization causes the on-demand synthesis and release of the ECs anandamide and 2-arachidonylglycerol. These bind to presynaptic cannabinoid type 1 (CB1) receptors, inhibiting further transmitter release. This process fine-tunes neurotransmission at the regional, neuronal-network pathway, and cellular/molecular levels. It also appears to play an important role in memory formation and extinction—mice with mutations of the CB1 receptor exhibit impaired long-term potentiation and decreased memory in general.
Cannabis derivatives, like THC and CBD, act as agonists (bind to) the CB1 receptor and have been shown to have therapeutic effects when used in appropriate doses. However, they do not produce the psychoactive or intoxicating effects of marijuana. Rather, they help to modulate the body’s endocannabinoid system by mimicking its natural ligands.
In this way, they help correct several imbalances in the ECS. Many studies have indicated that certain illnesses are associated with what is referred to as clinical endocannabinoid deficiency, a condition characterized by an altered the balance in the levels of ECs and their receptors or a loss of activity in the enzymes that control their synthesis and degradation.
Cannabinoid Receptors
In the 1980s, Mechoulam’s lab discovered a group of receptors on cells throughout the body called cannabinoid receptors, or CB1 and CB2 receptors. The receptors activate when certain chemicals, known as cannabinoids, attach or bind to them. These cannabinoids are naturally occurring, lipid-based neurotransmitters that help keep the body running smoothly. They’re also known as endogenous cannabinoids because your body, not cannabis plants, makes them. They’re made by the endocannabinoid system (ECS).
Scientists now know that ECS receptors are part of a larger cell-signaling network. They’re involved in many bodily functions, including pain control, memory processing, and motor control.
Cannabinoid receptors are part of a large family of G protein-coupled receptors found in all vertebrates. They’re activated by lipophilic compounds, or lipids, that include endocannabinoids, phytocannabinoids (found in Cannabis), and synthetic cannabinoids like HU-210.
Your body’s CB1 receptors are in your brain’s cerebellum, basal ganglia, and hippocampus. They’re also located in your gastrointestinal tract, and they control nausea. The anti-nausea effects of THC are largely due to its activation of your CB1 receptors. However, the GI tract’s interaction with THC is complicated. Overusing high-THC Cannabis can cause cannabinoid hyperemesis syndrome, which causes cyclical vomiting until the user stops smoking or using the product. This effect is lessened when using low-THC or CBD cannabis.
THC
THC, or tetrahydrocannabinol, is the primary psychoactive cannabinoid found in Cannabis plants. It is well-known that THC induces a “high” in users, and the feeling of relaxation and euphoria it causes is helpful for patients dealing with pain, anxiety, nausea and vomiting, and sleep issues. Will cannabis relieve nausea? There is considerable evidence that manipulation of the endocannabinoid system alleviates nausea and vomiting in various animal models (Parker and Limebeer, 2008). The anti-emetic effect is mediated via CB1 agonism, which suppresses vomiting and inversely, via CB1 antagonism, which promotes vomiting. These findings have led to the development of conventional pharmaceutical agents, including a synthetic analog of D9-THC called dronabinol (marketed as Marinol) and nabilone (marketed as Cesamet), which the FDA approves for use in cancer patients to treat chemotherapy-induced nausea and vomiting.
Research has also demonstrated that Cannabis can help with various other symptoms associated with cancer, such as anxiety, depression, disturbed sleep, fatigue and appetite loss. In one study, Cannabis users experienced a significant symptomatic improvement in these areas and showed similar overall survival to nonusers when treated with a standard of care. PDQ Cancer Information Summary for Health Professionals
CBD
Cannabis contains many chemical compounds, including delta-9-tetrahydrocannabinol (THC), that produce psychoactive effects. It also contains phytocannabinoids, such as CBD, cannabidiol, cannabigerol, and tetrahydrocannabivarin, that are thought to have important medical properties without the high associated with THC.
Studies suggest that CBD can reduce nausea and stimulate appetite. One study showed that a daily dose of CBD in patients with cancer increased the levels of the endocannabinoids anandamide and 2-arachidonoylglycerol, which are natural neurotransmitters that regulate nausea. Another study showed that oral CBD significantly reduced chemotherapy-induced nausea and vomiting in patients with a brain tumor.
The anti-emetic effects of Cannabis may be related to its ability to suppress 5-HT3 receptors. The first cannabinoid agonist approved by the FDA was the synthetic analog of D9-THC, dronabinol, which entered the clinic as Marinol in 1985. This drug is still used to suppress nausea and vomiting caused by certain cancer treatments.
However, research has shown some negative side effects of this medication, especially for males. It is believed that men who use this medication may have lower sperm counts, which could lead to infertility. However, more research needs to be done in this area. Cannabis is also known to interact with certain medications, so it is important to talk to your doctor about the risks and benefits of using this medication.
