Medical cannabis, or medical marijuana (MMJ), is
cannabis
''Cannabis'' () is a genus of flowering plants in the family Cannabaceae. The number of species within the genus is disputed. Three species may be recognized: '' Cannabis sativa'', '' C. indica'', and '' C. ruderalis''. Alternative ...
and
cannabinoid
Cannabinoids () are several structural classes of compounds found in the cannabis plant primarily and most animal organisms (although insects lack such receptors) or as synthetic compounds. The most notable cannabinoid is the phytocannabinoid tet ...
s that are
prescribed by
physician
A physician (American English), medical practitioner (Commonwealth English), medical doctor, or simply doctor, is a health professional who practices medicine, which is concerned with promoting, maintaining or restoring health through th ...
s for their patients. The use of cannabis as medicine has not been rigorously tested due to production and governmental restrictions, resulting in limited
clinical research
Clinical research is a branch of healthcare science that determines the safety and effectiveness ( efficacy) of medications, devices, diagnostic products and treatment regimens intended for human use. These may be used for prevention, treatm ...
to define the safety and efficacy of using cannabis to treat diseases.
Preliminary evidence has indicated that cannabis might reduce
nausea
Nausea is a diffuse sensation of unease and discomfort, sometimes perceived as an urge to vomit. While not painful, it can be a debilitating symptom if prolonged and has been described as placing discomfort on the chest, abdomen, or back of the ...
and
vomit
Vomiting (also known as emesis and throwing up) is the involuntary, forceful expulsion of the contents of one's stomach through the mouth and sometimes the nose.
Vomiting can be the result of ailments like food poisoning, gastroenterit ...
ing during
chemotherapy
Chemotherapy (often abbreviated to chemo and sometimes CTX or CTx) is a type of cancer treatment that uses one or more anti-cancer drugs ( chemotherapeutic agents or alkylating agents) as part of a standardized chemotherapy regimen. Chemothe ...
and reduce
chronic pain
Chronic pain is classified as pain that lasts longer than three to six months. In medicine, the distinction between acute and chronic pain is sometimes determined by the amount of time since onset. Two commonly used markers are pain that continue ...
and
muscle spasm
A spasm is a sudden involuntary contraction of a muscle, a group of muscles, or a hollow organ such as the bladder.
A spasmodic muscle contraction may be caused by many medical conditions, including dystonia. Most commonly, it is a muscl ...
s.
Regarding non-inhaled cannabis or cannabinoids, a 2021 review found that it provided little relief against chronic pain and sleep disturbance, and caused several transient
adverse effect
An adverse effect is an undesired harmful effect resulting from a medication or other intervention, such as surgery. An adverse effect may be termed a " side effect", when judged to be secondary to a main or therapeutic effect. The term compl ...
s, such as cognitive impairment, nausea, and drowsiness.
Short-term use increases the risk of minor and major adverse effects.
Common side effects include dizziness, feeling tired, vomiting, and hallucinations.
Long-term effects of cannabis are not clear.
Concerns include memory and cognition problems, risk of addiction,
schizophrenia
Schizophrenia is a mental disorder characterized by continuous or relapsing episodes of psychosis. Major symptoms include hallucinations (typically hearing voices), delusions, and disorganized thinking. Other symptoms include social wit ...
in young people, and the risk of children taking it by accident.
The ''Cannabis'' plant has a history of medicinal use dating back thousands of years in many cultures.
Some American medical organizations have requested removal of cannabis from the list of
Schedule I controlled substance
This is the list of Schedule I drugs as defined by the United States Controlled Substances Act. 21 CFRbr>1308.11(CSA Sched I) with changes through (Oct 18, 2012). Retrieved September 6, 2013. The following findings are required for drugs to be pla ...
s maintained by the United States federal government, followed by regulatory and scientific review.
Others oppose its legalization, such as the
American Academy of Pediatrics.
Medical cannabis can be administered through various methods, including
capsules,
lozenge
Lozenge or losange may refer to:
* Lozenge (shape), a type of rhombus
*Throat lozenge, a tablet intended to be dissolved slowly in the mouth to suppress throat ailments
*Lozenge (heraldry), a diamond-shaped object that can be placed on the field of ...
s,
tincture
A tincture is typically an extract of plant or animal material dissolved in ethanol (ethyl alcohol). Solvent concentrations of 25–60% are common, but may run as high as 90%.Groot Handboek Geneeskrachtige Planten by Geert Verhelst In chemistr ...
s,
dermal patch
A dermal patch or skin patch is a medicated adhesive patch that is placed on the skin to deliver a medication into the skin. This is in contrast to a transdermal patch, which delivers the medication through the skin and into the bloodstream.
...
es, oral or dermal sprays,
cannabis edible
A cannabis edible, also known as a cannabis-infused food or simply an edible, is a food product (either homemade or produced commercially) that contains decarboxylated cannabinoids (cannabinoid acids converted to their orally bioactive form) ...
s, and
vaporizing
Vaporization (or vaporisation) of an element or compound is a phase transition from the liquid phase to vapor. There are two types of vaporization: evaporation and boiling. Evaporation is a surface phenomenon, whereas boiling is a bulk phenom ...
or
smoking dried buds. Synthetic cannabinoids are available for prescription use in some countries, such as
dronabinol
The International Nonproprietary Name Dronabinol, also known as delta-9-tetrahydrocannabinol, or under the trade names Marinol, Syndros, Reduvo and Adversa, is a generic name for the molecule of delta-9-tetrahydrocannabinol in the pharmaceutic ...
and
nabilone
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 ...
. Countries that
allow the medical use of whole-plant cannabis include Australia, Canada, Chile, Colombia, Germany, Greece, Israel, Italy, the Netherlands, Peru, Poland, Portugal, and Uruguay. In the United States, 37 states and the District of Columbia have legalized cannabis for medical purposes, beginning with the passage of California's
Proposition 215
Proposition 215, or the Compassionate Use Act of 1996, is a California law permitting the use of medical cannabis despite marijuana's lack of the normal Food and Drug Administration testing for safety and efficacy. It was enacted, on November ...
in 1996.
Although cannabis remains prohibited for any use at the federal level, the
Rohrabacher–Farr amendment The Rohrabacher–Farr amendment (also known as the Rohrabacher–Blumenauer amendment) is legislation first introduced by U.S. Rep. Maurice Hinchey in 2001, prohibiting the Justice Department from spending funds to interfere with the implementation ...
was enacted in December 2014, limiting the ability of federal law to be enforced in states where medical cannabis has been legalized.
Classification
The
National Institute on Drug Abuse defines medical cannabis as "using the whole, unprocessed marijuana plant or its basic extracts to treat symptoms of illness and other conditions".
A cannabis plant includes more than 400 different chemicals, of which about 70 are
cannabinoid
Cannabinoids () are several structural classes of compounds found in the cannabis plant primarily and most animal organisms (although insects lack such receptors) or as synthetic compounds. The most notable cannabinoid is the phytocannabinoid tet ...
s.
In comparison, typical government-approved medications contain only one or two chemicals.
The number of active chemicals in cannabis is one reason why treatment with cannabis is difficult to classify and study.
A 2014 review stated that the variations in ratio of CBD-to-THC in botanical and pharmaceutical preparations determines the therapeutic vs psychoactive effects (CBD attenuates THC's psychoactive effects
) of cannabis products.
Medical uses
![Cannabis sativa (Köhler)](https://upload.wikimedia.org/wikipedia/commons/1/12/Cannabis_sativa_%28K%C3%B6hler%29.jpg)
Overall research into the health effects of medical cannabis has been of low quality and it is not clear whether it is a useful treatment for any condition, or whether harms outweight any benefit.
There is no consistent evidence that it helps with
chronic pain
Chronic pain is classified as pain that lasts longer than three to six months. In medicine, the distinction between acute and chronic pain is sometimes determined by the amount of time since onset. Two commonly used markers are pain that continue ...
and
muscle spasms
A spasm is a sudden involuntary contraction of a muscle, a group of muscles, or a hollow organ such as the bladder.
A spasmodic muscle contraction may be caused by many medical conditions, including dystonia. Most commonly, it is a muscle c ...
.
Low quality evidence suggests its use for reducing
nausea
Nausea is a diffuse sensation of unease and discomfort, sometimes perceived as an urge to vomit. While not painful, it can be a debilitating symptom if prolonged and has been described as placing discomfort on the chest, abdomen, or back of the ...
during
chemotherapy
Chemotherapy (often abbreviated to chemo and sometimes CTX or CTx) is a type of cancer treatment that uses one or more anti-cancer drugs ( chemotherapeutic agents or alkylating agents) as part of a standardized chemotherapy regimen. Chemothe ...
, improving appetite in
HIV/AIDS
Human immunodeficiency virus infection and acquired immunodeficiency syndrome (HIV/AIDS) is a spectrum of conditions caused by infection with the human immunodeficiency virus (HIV), a retrovirus. Following initial infection an individual ...
, improving sleep, and improving
tic
A tic is a sudden, repetitive, nonrhythmic motor movement or vocalization involving discrete muscle groups.American Psychiatric Association (2000)DSM-IV-TR: Tourette's Disorder.''Diagnostic and Statistical Manual of Mental Disorders'', 4th ed., ...
s in
Tourette syndrome
Tourette syndrome or Tourette's syndrome (abbreviated as TS or Tourette's) is a common neurodevelopmental disorder that begins in childhood or adolescence. It is characterized by multiple movement (motor) tics and at least one vocal (phonic) ...
.
When usual treatments are ineffective,
cannabinoid
Cannabinoids () are several structural classes of compounds found in the cannabis plant primarily and most animal organisms (although insects lack such receptors) or as synthetic compounds. The most notable cannabinoid is the phytocannabinoid tet ...
s have also been recommended for
anorexia
Anorexia nervosa, often referred to simply as anorexia, is an eating disorder characterized by low weight, food restriction, body image disturbance, fear of gaining weight, and an overpowering desire to be thin. ''Anorexia'' is a term of Gre ...
,
arthritis,
glaucoma
Glaucoma is a group of eye diseases that result in damage to the optic nerve (or retina) and cause vision loss. The most common type is open-angle (wide angle, chronic simple) glaucoma, in which the drainage angle for fluid within the eye rem ...
,
and
migraine.
It is unclear whether American states might be able to mitigate the adverse effects of the
opioid epidemic
The opioid epidemic, also referred to as the opioid crisis, is the rapid increase in the overuse, misuse/abuse, and overdose deaths attributed either in part or in whole to the class of drugs opiates/opioids since the 1990s. It includes the sign ...
by prescribing medical cannabis as an alternative pain management drug.
It is recommended that cannabis use be stopped in
pregnancy
Pregnancy is the time during which one or more offspring develops (gestation, gestates) inside a woman, woman's uterus (womb). A multiple birth, multiple pregnancy involves more than one offspring, such as with twins.
Pregnancy usually occur ...
.
Nausea and vomiting
Medical cannabis is somewhat effective in
chemotherapy-induced nausea and vomiting (CINV)
and may be a reasonable option in those who do not improve following preferential treatment.
Comparative studies have found cannabinoids to be more effective than some conventional antiemetics such as
prochlorperazine
Prochlorperazine, formerly sold under the brand name Compazine among others, is a medication used to treat nausea, migraines, schizophrenia, psychosis and anxiety. It is a less preferred medication for anxiety. It may be taken by mouth, rectally ...
,
promethazine
Promethazine is a first-generation antihistamine, antipsychotic, sedative, and antiemetic used to treat allergies, insomnia, and nausea. It may also help with some symptoms associated with the common cold and may also be used for sedating people ...
, and
metoclopramide
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 gastroesoph ...
in controlling CINV,
but these are used less frequently because of side effects including dizziness, dysphoria, and hallucinations.
Long-term cannabis use may cause nausea and vomiting, a condition known as
cannabinoid hyperemesis syndrome
Cannabinoid hyperemesis syndrome (CHS) is recurrent nausea, vomiting, and cramping abdominal pain that can occur due to prolonged, high-dose cannabis use. These symptoms may be relieved temporarily by taking a hot shower or bath. Complications ...
(CHS).
A 2016
Cochrane review
Cochrane (previously known as the Cochrane Collaboration) is a British international charitable organisation formed to organise medical research findings to facilitate evidence-based choices about health interventions involving health profes ...
said that cannabinoids were "probably effective" in treating chemotherapy-induced nausea in children, but with a high side-effect profile (mainly drowsiness, dizziness, altered moods, and increased appetite). Less common side effects were "ocular problems, orthostatic hypotension, muscle twitching, pruritus, vagueness, hallucinations, lightheadedness and dry mouth".
HIV/AIDS
Evidence is lacking for both efficacy and safety of cannabis and cannabinoids in treating patients with
HIV/AIDS
Human immunodeficiency virus infection and acquired immunodeficiency syndrome (HIV/AIDS) is a spectrum of conditions caused by infection with the human immunodeficiency virus (HIV), a retrovirus. Following initial infection an individual ...
or for
anorexia
Anorexia nervosa, often referred to simply as anorexia, is an eating disorder characterized by low weight, food restriction, body image disturbance, fear of gaining weight, and an overpowering desire to be thin. ''Anorexia'' is a term of Gre ...
associated with AIDS. As of 2013, current studies suffer from the effects of bias, small sample size, and lack of long-term data.
Pain
A 2021 review found little effect of using non-inhaled cannabis to relieve chronic pain.
[ According to a 2019 systematic review, there have been inconsistent results of using cannabis for neuropathic pain, spasms associated with multiple sclerosis and pain from ]rheumatic
Rheumatology (Greek ''ῥεῦμα'', ''rheûma'', flowing current) is a branch of medicine devoted to the diagnosis and management of disorders whose common feature is inflammation in the bones, muscles, joints, and internal organs. Rheumatolog ...
disorders, but was not effective treating chronic cancer pain. The authors state that additional randomized controlled trials of different cannabis products are necessary to make conclusive recommendations.[
When cannabis is inhaled to relieve pain, blood levels of cannabinoids rise faster than when oral products are used, peaking within three minutes and attaining an analgesic effect in seven minutes.]
A 2011 review considered cannabis to be generally safe, and it appears safer than opioid
Opioids are substances that act on opioid receptors to produce morphine-like effects. Medically they are primarily used for pain relief, including anesthesia. Other medical uses include suppression of diarrhea, replacement therapy for opioid use ...
s in palliative care.
A 2022 review concluded the pain relief experienced after using medical cannabis is due to the placebo effect
A placebo ( ) is a substance or treatment which is designed to have no therapeutic value. Common placebos include inert tablets (like sugar pills), inert injections (like Saline (medicine), saline), sham surgery, and other procedures.
In general ...
, especially given widespread media attention that sets the expectation for pain relief.
Neurological conditions
Cannabis' efficacy is not clear in treating neurological problems, including multiple sclerosis (MS) and movement problems. Evidence also suggests that oral cannabis extract is effective for reducing patient-centered measures of spasticity. A trial of cannabis is deemed to be a reasonable option if other treatments have not been effective. Its use for MS is approved in ten countries. A 2012 review found no problems with tolerance, abuse, or addiction. In the United States, cannabidiol
Cannabidiol (CBD) is a phytocannabinoid discovered in 1940. It is one of 113 identified cannabinoids in cannabis plants, along with tetrahydrocannabinol (THC), and accounts for up to 40% of the plant's extract. , clinical research on CBD in ...
, one of the cannabinoids found in the marijuana plant, has been approved for treating two severe forms of epilepsy, Lennox-Gastaut syndrome and Dravet syndrome
Dravet syndrome, previously known as severe myoclonic epilepsy of infancy (SMEI), is an autosomal dominant genetic disorder which causes a catastrophic form of epilepsy, with prolonged seizures that are often triggered by hot temperatures or feve ...
.
Mental disorders
A 2019 systematic review found that there is a lack of evidence that cannabinoids are effective in treating depressive or anxiety disorders, attention-deficit hyperactivity disorder
Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder characterised by excessive amounts of inattention, hyperactivity, and impulsivity that are pervasive, impairing in multiple contexts, and otherwise age-inappr ...
(ADHD), Tourette syndrome
Tourette syndrome or Tourette's syndrome (abbreviated as TS or Tourette's) is a common neurodevelopmental disorder that begins in childhood or adolescence. It is characterized by multiple movement (motor) tics and at least one vocal (phonic) ...
, post-traumatic stress disorder
Post-traumatic stress disorder (PTSD) is a mental and behavioral disorder that can develop because of exposure to a traumatic event, such as sexual assault, warfare, traffic collisions, child abuse, domestic violence, or other threats o ...
, or psychosis
Psychosis is a condition of the mind that results in difficulties determining what is real and what is not real. Symptoms may include delusions and hallucinations, among other features. Additional symptoms are incoherent speech and behavior ...
.
Adverse effects
Medical use
There is insufficient data to draw strong conclusions about the safety of medical cannabis. Typically, adverse effects of medical cannabis use are not serious; they include tiredness, dizziness, increased appetite, and cardiovascular and psychoactive effects. Other effects can include impaired short-term memory; impaired motor coordination; altered judgment; and paranoia or psychosis at high doses. Tolerance to these effects develops over a period of days or weeks. The amount of cannabis normally used for medicinal purposes is not believed to cause any permanent cognitive impairment in adults, though long-term treatment in adolescents should be weighed carefully as they are more susceptible to these impairments. Withdrawal symptoms are rarely a problem with controlled medical administration of cannabinoids. The ability to drive vehicles or to operate machinery may be impaired until a tolerance is developed. Although supporters of medical cannabis say that it is safe, further research is required to assess the long-term safety of its use.
Cognitive effects
Recreational use of cannabis is associated with cognitive deficits, especially for those who begin to use cannabis in adolescence. there is a lack of research into long-term cognitive effects of medical use of cannabis, but one 12-month observational study reported that "MC patients demonstrated significant improvements on measures of executive function
In cognitive science and neuropsychology, executive functions (collectively referred to as executive function and cognitive control) are a set of cognitive processes that are necessary for the cognitive control of behavior: selecting and succ ...
and clinical state over the course of 12 months".
Impact on psychosis
Exposure to THC can cause acute transient psychotic symptoms in healthy individuals and people with schizophrenia.
A 2007 meta analysis concluded that cannabis use reduced the average age of onset of psychosis by 2.7 years relative to non-cannabis use. A 2005 meta analysis concluded that adolescent use of cannabis increases the risk of psychosis, and that the risk is dose-related. A 2004 literature review on the subject concluded that cannabis use is associated with a two-fold increase in the risk of psychosis, but that cannabis use is "neither necessary nor sufficient" to cause psychosis. A French review from 2009 came to a conclusion that cannabis use, particularly that before age 15, was a factor in the development of schizophrenic disorders.
Pharmacology
The genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...
''Cannabis
''Cannabis'' () is a genus of flowering plants in the family Cannabaceae. The number of species within the genus is disputed. Three species may be recognized: '' Cannabis sativa'', '' C. indica'', and '' C. ruderalis''. Alternative ...
'' contains two species which produce useful amounts of psychoactive cannabinoids: ''Cannabis indica
''Cannabis indica'' is an annual plant species in the family Cannabaceae which produces large amounts of tetrahydrocannabinol (THC) and is cultivated for purposes including hashish in India. The high concentrations of THC provide euphoric effec ...
'' and ''Cannabis sativa
''Cannabis sativa'' is an annual herbaceous flowering plant indigenous to Eastern Asia, but now of cosmopolitan distribution due to widespread cultivation. It has been cultivated throughout recorded history, used as a source of industrial fibe ...
'', which are listed as Schedule I medicinal plants in the US; a third species, ''Cannabis ruderalis
''Cannabis ruderalis'' is a variety, subspecies, or species of ''Cannabis'' native to Central and Eastern Europe and Russia. It contains a relatively low quantity of psychoactive compound tetrahydrocannabinol (THC) Some scholars accept ''C.&nb ...
'', has few psychogenic properties. Cannabis contains more than 460 compounds; at least 80 of these are cannabinoid
Cannabinoids () are several structural classes of compounds found in the cannabis plant primarily and most animal organisms (although insects lack such receptors) or as synthetic compounds. The most notable cannabinoid is the phytocannabinoid tet ...
s – chemical compound
A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one element ...
s that interact with cannabinoid receptor
Cannabinoid receptors, located throughout the body, are part of the endocannabinoid system a class of cell membrane receptors in the G protein-coupled receptor superfamily. As is typical of G protein-coupled receptors, the cannabinoid recep ...
s in the brain. As of 2012, more than 20 cannabinoids were being studied by the U.S. FDA.
The most psychoactive cannabinoid found in the cannabis plant is tetrahydrocannabinol
Tetrahydrocannabinol (THC) 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' ...
(or delta-9-tetrahydrocannabinol, commonly known as THC). Other cannabinoids include delta-8-tetrahydrocannabinol, cannabidiol
Cannabidiol (CBD) is a phytocannabinoid discovered in 1940. It is one of 113 identified cannabinoids in cannabis plants, along with tetrahydrocannabinol (THC), and accounts for up to 40% of the plant's extract. , clinical research on CBD in ...
(CBD), cannabinol
Cannabinol (CBN) is a mildly psychoactive cannabinoid that acts as a low affinity partial agonist at both CB1 and CB2 receptors. This activity at CB1 and CB2 receptors constitutes interaction of CBN with the endocannabinoid system (ECS).
CBN ...
(CBN), cannabicyclol
Cannabicyclol (CBL) is a non- psychoactive cannabinoid found in ''Cannabis''. CBL is a degradative product like cannabinol, with cannabichromene degrading into CBL through natural irradiation or under acid conditions.
CBL is not scheduled under ...
(CBL), cannabichromene (CBC) and cannabigerol
Cannabigerol (CBG) is one of more than 120 identified cannabinoid compounds found in the plant genus ''Cannabis''. Cannabigerol is the decarboxylated form of cannabigerolic acid, the parent molecule from which other cannabinoids are synthesized ...
(CBG); they have less psychotropic effects than THC, but may play a role in the overall effect of cannabis. The most studied are THC, CBD and CBN.
CB1 and CB2 are the primary cannabinoid receptors responsible for several of the effects of cannabinoids, although other receptors may play a role as well. Both belong to a group of receptors called G protein-coupled receptors (GPCRs). CB1 receptors are found in very high levels in the brain and are thought to be responsible for psychoactive effects. CB2 receptors are found peripherally throughout the body and are thought to modulate pain and inflammation.
Absorption
Cannabinoid absorption is dependent on its route of administration.
Inhaled and vaporized THC have similar absorption profiles to smoked THC, with a bioavailability ranging from 10 to 35%. Oral administration has the lowest bioavailability of approximately 6%, variable absorption depending on the vehicle used, and the longest time to peak plasma levels (2 to 6 hours) compared to smoked or vaporized THC.
Similar to THC, CBD has poor oral bioavailability, approximately 6%. The low bioavailability is largely attributed to significant first-pass metabolism in the liver and erratic absorption from the gastrointestinal tract. However, oral administration of CBD has a faster time to peak concentrations (2 hours) than THC.
Due to the poor bioavailability of oral preparations, alternative routes of administration have been studied, including sublingual and rectal. These alternative formulations maximize bioavailability and reduce first-pass metabolism. Sublingual administration in rabbits yielded bioavailability of 16% and time to peak concentration of 4 hours. Rectal administration in monkeys doubled bioavailability to 13.5% and achieved peak blood concentrations within 1 to 8 hours after administration.
Distribution
Like cannabinoid absorption, distribution is also dependent on route of administration. Smoking and inhalation of vaporized cannabis have better absorption than do other routes of administration, and therefore also have more predictable distribution. THC is highly protein bound once absorbed, with only 3% found unbound in the plasma. It distributes rapidly to highly vascularized organs such as the heart, lungs, liver, spleen, and kidneys, as well as to various glands. Low levels can be detected in the brain, testes, and unborn fetuses, all of which are protected from systemic circulation via barriers. THC further distributes into fatty tissues a few days after administration due to its high lipophilicity, and is found deposited in the spleen and fat after redistribution.
Metabolism
Delta-9-THC is the primary molecule responsible for the effects of cannabis. Delta-9-THC is metabolized in the liver and turns into 11-OH-THC. 11-OH-THC is the first metabolic product in this pathway. Both Delta-9-THC and 11-OH-THC are psychoactive. The metabolism of THC into 11-OH-THC plays a part in the heightened psychoactive effects of edible cannabis.
Next, 11-OH-THC is metabolized in the liver into 11-COOH-THC, which is the second metabolic product of THC. 11-COOH-THC is not psychoactive.
Ingestion of edible cannabis products lead to a slower onset of effect than the inhalation of it because the THC travels to the liver first through the blood before it travels to the rest of the body. Inhaled cannabis can result in THC going directly to the brain, where it then travels from the brain back to the liver in recirculation for metabolism. Eventually, both routes of metabolism result in the metabolism of psychoactive THC to inactive 11-COOH-THC.
Excretion
Due to substantial metabolism of THC and CBD, their metabolites are excreted mostly via feces, rather than by urine. After delta-9-THC is hydroxylated into 11-OH-THC via CYP2C9, CYP2C19, and CYP3A4, it undergoes phase II metabolism into more than 30 metabolites, a majority of which are products of glucuronidation
Glucuronidation is often involved in drug metabolism of substances such as drugs, pollutants, bilirubin, androgens, estrogens, mineralocorticoids, glucocorticoids, fatty acid derivatives, retinoids, and bile acids. These linkages involve gl ...
. Approximately 65% of THC is excreted in feces and 25% in the urine, while the remaining 10% is excreted by other means. The terminal half-life of THC is 25 to 36 hours, whereas for CBD it is 18 to 32 hours.[
CBD is hydroxylated by P450 liver enzymes into 7-OH-CBD. Its metabolites are products of primarily CYP2C19 and CYP3A4 activity, with potential activity of CYP1A1, CYP1A2, CYP2C9, and CYP2D6. Similar to delta-9-THC, a majority of CBD is excreted in feces and some in the urine.] The terminal half-life is approximately 18–32 hours.
Administration
Smoking has been the means of administration of cannabis for many users, but it is not suitable for the use of cannabis as a medicine. It was the most common method of medical cannabis consumption in the US . It is difficult to predict the pharmacological response to cannabis because concentration of cannabinoids varies widely, as there are different ways of preparing it for consumption (smoked, applied as oils, eaten, infused into other foods, or drunk) and a lack of production controls. The potential for adverse effects from smoke inhalation makes smoking a less viable option than oral preparations. Cannabis vaporizers have gained popularity because of a perception among users that fewer harmful chemicals are ingested when components are inhaled via aerosol rather than smoke. Cannabinoid medicines are available in pill form (dronabinol
The International Nonproprietary Name Dronabinol, also known as delta-9-tetrahydrocannabinol, or under the trade names Marinol, Syndros, Reduvo and Adversa, is a generic name for the molecule of delta-9-tetrahydrocannabinol in the pharmaceutic ...
and nabilone
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 ...
) and liquid extracts formulated into an oromucosal spray (nabiximols
Nabiximols (USAN, trade 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 blad ...
). Oral preparations are "problematic due to the uptake of cannabinoids into fatty tissue, from which they are released slowly, and the significant first-pass liver metabolism, which breaks down Δ9THC and contributes further to the variability of plasma concentrations".
The US Food and Drug Administration (FDA) has not approved smoked cannabis for any condition or disease, as it deems that evidence is lacking concerning safety and efficacy. The FDA issued a 2006 advisory against ''smoked'' medical cannabis stating: "marijuana has a high potential for abuse, has no currently accepted medical use in treatment in the United States, and has a lack of accepted safety for use under medical supervision."
History
Ancient
Cannabis, called ''má'' 麻 (meaning "hemp; cannabis; numbness") or ''dàmá'' 大麻 (with "big; great") in Chinese, was used in Taiwan
Taiwan, officially the Republic of China (ROC), is a country in East Asia, at the junction of the East and South China Seas in the northwestern Pacific Ocean, with the People's Republic of China (PRC) to the northwest, Japan to the nort ...
for fiber starting about 10,000 years ago. The botanist Hui-lin Li wrote that in China, "The use of Cannabis in medicine was probably a very early development. Since ancient humans used hemp seed as food, it was quite natural for them to also discover the medicinal properties of the plant." Emperor Shen-Nung, who was also a pharmacologist, wrote a book on treatment methods in 2737 BCE that included the medical benefits of cannabis. He recommended the substance for many ailments, including constipation, gout, rheumatism, and absent-mindedness. Cannabis is one of the 50 "fundamental" herbs in traditional Chinese medicine
Traditional Chinese medicine (TCM) is an alternative medical practice drawn from traditional medicine in China. It has been described as "fraught with pseudoscience", with the majority of its treatments having no logical mechanism of acti ...
.
The Ebers Papyrus () from Ancient Egypt describes medical cannabis.[ ] The ancient Egyptians used hemp (cannabis) in suppositories for relieving the pain of hemorrhoid
Hemorrhoids (or haemorrhoids), also known as piles, are vascular structures in the anal canal. In their normal state, they are cushions that help with stool control. They become a disease when swollen or inflamed; the unqualified term ''he ...
s.
Surviving texts from ancient India
According to consensus in modern genetics, anatomically modern humans first arrived on the Indian subcontinent from Africa between 73,000 and 55,000 years ago. Quote: "Y-Chromosome and Mt-DNA data support the colonization of South Asia by m ...
confirm that cannabis' psychoactive properties were recognized, and doctors used it for treating a variety of illnesses and ailments, including insomnia, headaches, gastrointestinal disorders, and pain, including during childbirth.
The Ancient Greeks
Ancient Greece ( el, Ἑλλάς, Hellás) was a northeastern Mediterranean civilization, existing from the Greek Dark Ages of the 12th–9th centuries BC to the end of classical antiquity ( AD 600), that comprised a loose collection of cult ...
used cannabis to dress wounds and sores on their horses, and in humans, dried leaves of cannabis were used to treat nose bleeds, and cannabis seeds were used to expel tapeworms.
In the medieval Islamic world, Arabic physicians made use of the diuretic
A diuretic () is any substance that promotes diuresis, the increased production of urine. This includes forced diuresis. A diuretic tablet is sometimes colloquially called a water tablet. There are several categories of diuretics. All diuretics i ...
, antiemetic
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 m ...
, antiepileptic
Anticonvulsants (also known as antiepileptic drugs or recently as antiseizure drugs) are a diverse group of pharmacological agents used in the treatment of epileptic seizures. Anticonvulsants are also increasingly being used in the treatment of b ...
, anti-inflammatory
Anti-inflammatory is the property of a substance or treatment that reduces inflammation or swelling. Anti-inflammatory drugs, also called anti-inflammatories, make up about half of analgesics. These drugs remedy pain by reducing inflammation as o ...
, analgesic and antipyretic
An antipyretic (, from ''anti-'' 'against' and ' 'feverish') is a substance that reduces fever. Antipyretics cause the hypothalamus to override a prostaglandin-induced increase in temperature. The body then works to lower the temperature, which r ...
properties of ''Cannabis sativa
''Cannabis sativa'' is an annual herbaceous flowering plant indigenous to Eastern Asia, but now of cosmopolitan distribution due to widespread cultivation. It has been cultivated throughout recorded history, used as a source of industrial fibe ...
'', and used it extensively as medication from the 8th to 18th centuries.
Landrace strains
Cannabis seeds may have been used for food, rituals or religious practices in ancient Europe and China. Harvesting the plant led to the spread of cannabis throughout Eurasia
Eurasia (, ) is the largest continental area on Earth, comprising all of Europe and Asia. Primarily in the Northern and Eastern Hemispheres, it spans from the British Isles and the Iberian Peninsula in the west to the Japanese archipelago ...
about 10,000 to 5,000 years ago, with further distribution to the Middle East
The Middle East ( ar, الشرق الأوسط, ISO 233: ) is a geopolitical region commonly encompassing Arabia (including the Arabian Peninsula and Bahrain), Asia Minor (Asian part of Turkey except Hatay Province), East Thrace (Europ ...
and Africa about 2,000 to 500 years ago. A landrace
A landrace is a domesticated, locally adapted, often traditional variety of a species of animal or plant that has developed over time, through adaptation to its natural and cultural environment of agriculture and pastoralism, and due to isolatio ...
strain
Strain may refer to:
Science and technology
* Strain (biology), variants of plants, viruses or bacteria; or an inbred animal used for experimental purposes
* Strain (chemistry), a chemical stress of a molecule
* Strain (injury), an injury to a mu ...
of cannabis developed over centuries. They are cultivars of the plant that originated in one specific region.
Widely cultivated strains of cannabis, such as "Afghani" or "Hindu Kush", are indigenous to the Pakistan
Pakistan ( ur, ), officially the Islamic Republic of Pakistan ( ur, , label=none), is a country in South Asia. It is the world's fifth-most populous country, with a population of almost 243 million people, and has the world's second-lar ...
and Afghanistan
Afghanistan, officially the Islamic Emirate of Afghanistan,; prs, امارت اسلامی افغانستان is a landlocked country located at the crossroads of Central Asia and South Asia. Referred to as the Heart of Asia, it is bordere ...
regions, while "Durban Poison" is native to Africa. There are approximately 16 landrace strains of cannabis identified from Pakistan, Jamaica, Africa, Mexico, Central America and Asia.
Modern
An Irish physician, William Brooke O'Shaughnessy, is credited with introducing cannabis to Western medicine. O'Shaughnessy discovered cannabis in the 1830s while living abroad in India
India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...
, where he conducted numerous experiments investigating the drug's medical utility (noting in particular its analgesic and anticonvulsant effects). He returned to England
England is a country that is part of the United Kingdom. It shares land borders with Wales to its west and Scotland to its north. The Irish Sea lies northwest and the Celtic Sea to the southwest. It is separated from continental Europe b ...
with a supply of cannabis in 1842, after which its use spread through Europe and the United States. In 1845 French physician Jacques-Joseph Moreau
Jacques-Joseph Moreau (3 June 1804 – 26 June 1884), nicknamed "Moreau de Tours", was a French psychiatrist and member of the Club des Hashischins. Moreau was the first physician to do systematic work on drugs' effects on the central nervo ...
published a book about the use of cannabis in psychiatry. In 1850 cannabis was entered into the United States Pharmacopeia
The ''United States Pharmacopeia'' (''USP'') is a pharmacopeia (compendium of drug information) for the United States published annually by the United States Pharmacopeial Convention (usually also called the USP), a nonprofit organization that ...
. An anecdotal report of ''Cannabis indica
''Cannabis indica'' is an annual plant species in the family Cannabaceae which produces large amounts of tetrahydrocannabinol (THC) and is cultivated for purposes including hashish in India. The high concentrations of THC provide euphoric effec ...
'' as a treatment for tetanus
Tetanus, also known as lockjaw, is a bacterial infection caused by ''Clostridium tetani'', and is characterized by muscle spasms. In the most common type, the spasms begin in the jaw and then progress to the rest of the body. Each spasm usually ...
appeared in Scientific American
''Scientific American'', informally abbreviated ''SciAm'' or sometimes ''SA'', is an American popular science magazine. Many famous scientists, including Albert Einstein and Nikola Tesla, have contributed articles to it. In print since 1845, it ...
in 1880.
The use of cannabis in medicine began to decline by the end of the 19th century, due to difficulty in controlling dosages and the rise in popularity of synthetic and opium-derived drugs. Also, the advent of the hypodermic syringe allowed these drugs to be injected for immediate effect, in contrast to cannabis which is not water-soluble and therefore cannot be injected.
In the United States, the medical use of cannabis further declined with the passage of the Marihuana Tax Act of 1937
The Marihuana Tax Act of 1937, , was a United States Act that placed a tax on the sale of cannabis. The H.R. 6385 act was drafted by Harry Anslinger and introduced by Rep. Robert L. Doughton of North Carolina, on April 14, 1937. The Seventy-fift ...
, which imposed new regulations and fees on physicians prescribing cannabis. Cannabis was removed from the U.S. Pharmacopeia in 1941, and officially banned for any use with the passage of the Controlled Substances Act of 1970.
Cannabis began to attract renewed interest as medicine in the 1970s and 1980s, in particular due to its use by cancer and AIDS patients who reported relief from the effects of chemotherapy
Chemotherapy (often abbreviated to chemo and sometimes CTX or CTx) is a type of cancer treatment that uses one or more anti-cancer drugs ( chemotherapeutic agents or alkylating agents) as part of a standardized chemotherapy regimen. Chemothe ...
and wasting syndrome
Cachexia () is a complex syndrome associated with an underlying illness, causing ongoing muscle loss that is not entirely reversed with nutritional supplementation. A range of diseases can cause cachexia, most commonly cancer, congestive heart f ...
. In 1996, California
California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the m ...
became the first U.S. state to legalize medical cannabis in defiance of federal law. In 2001, Canada
Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...
became the first country to adopt a system regulating the medical use of cannabis.
File:Da-ma.png, The use of cannabis, at least as fiber, has been shown to go back at least 10,000 years in Taiwan
Taiwan, officially the Republic of China (ROC), is a country in East Asia, at the junction of the East and South China Seas in the northwestern Pacific Ocean, with the People's Republic of China (PRC) to the northwest, Japan to the nort ...
. "Dà má" (Pinyin
Hanyu Pinyin (), often shortened to just pinyin, is the official romanization system for Standard Chinese, Standard Mandarin Chinese in China, and to some extent, in Singapore and Malaysia. It is often used to teach Mandarin, normally writte ...
pronunciation) is the Chinese expression for cannabis, the first character meaning "big" and the second character meaning "hemp".
File:Drug bottle containing cannabis.jpg, ''Cannabis indica'' fluid extract, American Druggists Syndicate, pre-1937
File:CannabisAmericana JLHopkins B.jpg, An advertisement for ''cannabis americana'' distributed by a pharmacist in New York in 1917
File:PEbers c41-bc.jpg, The Ebers Papyrus () from Ancient Egypt has a prescription for medical marijuana applied directly for inflammation.
Society and culture
Legal status
Countries that have legalized the medical use of cannabis include Australia, Brazil
Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...
, Canada
Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...
, Chile
Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and the closest to Antarctica, occupying a long and narrow strip of land between the Andes to the east a ...
, Colombia, Croatia
, image_flag = Flag of Croatia.svg
, image_coat = Coat of arms of Croatia.svg
, anthem = "Lijepa naša domovino"("Our Beautiful Homeland")
, image_map =
, map_caption =
, capit ...
, Cyprus
Cyprus ; tr, Kıbrıs (), officially the Republic of Cyprus,, , lit: Republic of Cyprus is an island country located south of the Anatolian Peninsula in the eastern Mediterranean Sea. Its continental position is disputed; while it is ge ...
, Czech Republic
The Czech Republic, or simply Czechia, is a landlocked country in Central Europe. Historically known as Bohemia, it is bordered by Austria to the south, Germany to the west, Poland to the northeast, and Slovakia to the southeast. The ...
, Finland
Finland ( fi, Suomi ; sv, Finland ), officially the Republic of Finland (; ), is a Nordic country in Northern Europe. It shares land borders with Sweden to the northwest, Norway to the north, and Russia to the east, with the Gulf of B ...
, Germany
Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwe ...
, Greece
Greece,, or , romanized: ', officially the Hellenic Republic, is a country in Southeast Europe. It is situated on the southern tip of the Balkans, and is located at the crossroads of Europe, Asia, and Africa. Greece shares land borders ...
, Israel
Israel (; he, יִשְׂרָאֵל, ; ar, إِسْرَائِيل, ), officially the State of Israel ( he, מְדִינַת יִשְׂרָאֵל, label=none, translit=Medīnat Yīsrāʾēl; ), is a country in Western Asia. It is situated ...
, Italy
Italy ( it, Italia ), officially the Italian Republic, ) or the Republic of Italy, is a country in Southern Europe. It is located in the middle of the Mediterranean Sea, and its territory largely coincides with the homonymous geographical ...
, Jamaica
Jamaica (; ) is an island country situated in the Caribbean Sea. Spanning in area, it is the third-largest island of the Greater Antilles and the Caribbean (after Cuba and Hispaniola). Jamaica lies about south of Cuba, and west of His ...
, Lebanon
Lebanon ( , ar, لُبْنَان, translit=lubnān, ), officially the Republic of Lebanon () or the Lebanese Republic, is a country in Western Asia. It is located between Syria to Lebanon–Syria border, the north and east and Israel to Blue ...
, Luxembourg
Luxembourg ( ; lb, Lëtzebuerg ; french: link=no, Luxembourg; german: link=no, Luxemburg), officially the Grand Duchy of Luxembourg, ; french: link=no, Grand-Duché de Luxembourg ; german: link=no, Großherzogtum Luxemburg is a small lan ...
, North Macedonia
North Macedonia, ; sq, Maqedonia e Veriut, (Macedonia before February 2019), officially the Republic of North Macedonia,, is a country in Southeast Europe. It gained independence in 1991 as one of the successor states of Yugoslavia. It ...
, Malta
Malta ( , , ), officially the Republic of Malta ( mt, Repubblika ta' Malta ), is an island country in the Mediterranean Sea. It consists of an archipelago, between Italy and Libya, and is often considered a part of Southern Europe. It lies ...
, the Netherlands
)
, anthem = ( en, "William of Nassau")
, image_map =
, map_caption =
, subdivision_type = Sovereign state
, subdivision_name = Kingdom of the Netherlands
, established_title = Before independence
, established_date = Spanish Netherl ...
, New Zealand
New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...
, Peru
, image_flag = Flag of Peru.svg
, image_coat = Escudo nacional del Perú.svg
, other_symbol = Great Seal of the State
, other_symbol_type = National seal
, national_motto = "Firm and Happy f ...
, Poland
Poland, officially the Republic of Poland, is a country in Central Europe. It is divided into 16 administrative provinces called voivodeships, covering an area of . Poland has a population of over 38 million and is the fifth-most populou ...
, Portugal
Portugal, officially the Portuguese Republic ( pt, República Portuguesa, links=yes ), is a country whose mainland is located on the Iberian Peninsula of Southwestern Europe, and whose territory also includes the Atlantic archipelagos of ...
, Sri Lanka, Thailand
Thailand ( ), historically known as Siam () and officially the Kingdom of Thailand, is a country in Southeast Asia, located at the centre of the Indochinese Peninsula, spanning , with a population of almost 70 million. The country is b ...
, the United Kingdom
The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the European mainland, continental mainland. It comprises England, Scotlan ...
, and Uruguay
Uruguay (; ), officially the Oriental Republic of Uruguay ( es, República Oriental del Uruguay), is a country in South America. It shares borders with Argentina to its west and southwest and Brazil to its north and northeast; while bordering ...
. Other countries have more restrictive laws that allow only the use of isolated cannabinoid drugs such as Sativex
Nabiximols (USAN, trade 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 bla ...
or Epidiolex
Cannabidiol (CBD) is a phytocannabinoid discovered in 1940. It is one of 113 identified cannabinoids in cannabis plants, along with tetrahydrocannabinol (THC), and accounts for up to 40% of the plant's extract. , clinical research on CBD incl ...
. Countries with the most relaxed policies include Canada, Uruguay, and the Netherlands, where cannabis can be purchased without need for a prescription. In Mexico
Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...
, THC content of medical cannabis is limited to one percent. The same limit applies in Switzerland, but no prescription is required to purchase. In the United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territori ...
, the legality of medical cannabis varies by state.
Cannabis and its derivatives are subject to regulation under three United Nations
The United Nations (UN) is an intergovernmental organization whose stated purposes are to maintain international peace and security, develop friendly relations among nations, achieve international cooperation, and be a centre for harmoniz ...
treaties: the 1961 Single Convention on Narcotic Drugs
The Single Convention on Narcotic Drugs, 1961 (Single Convention, 1961 Convention, or C61) is an international treaty that controls activities (cultivation, production, supply, trade, transport) of specific narcotic drugs and lays down a syste ...
, the 1971 Convention on Psychotropic Substances, and the 1988 Convention Against Illicit Traffic in Narcotic Drugs and Psychotropic Substances. Cannabis is classified as a Schedule I drug under the Single Convention treaty, meaning that medical use is allowed but that it is considered to be an addictive drug with a serious risk of abuse – along with other drugs such as opium and cocaine. Prior to December 2020 it was also included in Schedule IV, a subset of Schedule I, which is for only the most dangerous drugs such as heroin and fentanyl. Member nations of the UN Commission on Narcotic Drugs
The Commission on Narcotic Drugs (CND) is one of the functional commissions of the United Nations' Economic and Social Council (ECOSOC), and is the central drug policy-making body within the United Nations System. The CND also has important man ...
voted 27–25 to remove it from Schedule IV on 2 December 2020, following a World Health Organization
The World Health Organization (WHO) is a specialized agency of the United Nations responsible for international public health. The WHO Constitution states its main objective as "the attainment by all peoples of the highest possible level of ...
recommendation for removal in January 2019.
United States
In the United States, the use of cannabis for medical purposes is legal in 37 states, three out of five permanently inhabited U.S. territories
Territories of the United States are sub-national administrative divisions overseen by the federal government of the United States. The various American territories differ from the U.S. states and tribal reservations as they are not sover ...
, and the District of Columbia
)
, image_skyline =
, image_caption = Clockwise from top left: the Washington Monument and Lincoln Memorial on the National Mall, United States Capitol, Logan Circle, Jefferson Memorial, White House, Adams Morgan, ...
. An additional 11 states have more restrictive laws allowing the use of low-THC products. Cannabis remains illegal at the federal level under the Controlled Substances Act, which classifies it as a Schedule I drug with a high potential for abuse and no accepted medical use. In December 2014, however, the Rohrabacher–Farr amendment The Rohrabacher–Farr amendment (also known as the Rohrabacher–Blumenauer amendment) is legislation first introduced by U.S. Rep. Maurice Hinchey in 2001, prohibiting the Justice Department from spending funds to interfere with the implementation ...
was signed into law, prohibiting the Justice Department from prosecuting individuals acting in accordance with state medical cannabis laws.
Economics
Distribution
The method of obtaining medical cannabis varies by region and by legislation. In the US, most consumers grow their own or buy it from cannabis dispensaries in states where it is legal. Marijuana vending machines for selling or dispensing cannabis are in use in the United States and are planned to be used in Canada. In 2014, the startup Meadow began offering on-demand delivery of medical marijuana in the San Francisco Bay Area, through their mobile app.
Almost 70% of medical cannabis is exported from the United Kingdom, according to a 2017 United Nations report, with much of the remaining amount coming from Canada and the Netherlands.
Insurance
In the United States, health insurance companies may not pay for a medical marijuana prescription as the Food and Drug Administration
The United States Food and Drug Administration (FDA or US FDA) is a List of United States federal agencies, federal agency of the United States Department of Health and Human Services, Department of Health and Human Services. The FDA is respon ...
must approve any substance for medicinal purposes. Before this can happen, the FDA must first permit the study of the medical benefits and drawbacks of the substance, which it has not done since it was placed on Schedule I of the Controlled Substances Act in 1970. Therefore, all expenses incurred fulfilling a medical marijuana prescription will possibly be incurred as out-of-pocket. However, the New Mexico Court of Appeals has ruled that workers' compensation
Workers' compensation or workers' comp is a form of insurance providing wage replacement and medical benefits to employees injured in the course of employment in exchange for mandatory relinquishment of the employee's right to sue his or her emp ...
insurance must pay for prescribed marijuana as part of the state's Medical Cannabis Program.
Positions of medical organizations
Medical organizations that have issued statements in support of allowing access to medical cannabis include the American Nurses Association
The American Nurses Association (ANA) is a 501(c)(6) professional organization to advance and protect the profession of nursing. It started in 1896 as the Nurses Associated Alumnae and was renamed the American Nurses Association in 1911. It is b ...
, American Public Health Association, American Medical Student Association
The American Medical Student Association (AMSA), founded in 1950 and based in Washington, D.C., is an independent association of physicians-in-training in the United States. AMSA is a student-governed national organization.They have a membership ...
, National Multiple Sclerosis Society
The National Multiple Sclerosis Society (NMSS) is a nonprofit organization that was founded in New York City as the Association for Advancement of Research on Multiple Sclerosis on March 11, 1946 by Sylvia Lawry. Ms. Lawry was a lawyer looking fo ...
, Epilepsy Foundation
The Epilepsy Foundation, also Epilepsy Foundation of America (EFA), is a non-profit national foundation, headquartered in Bowie, Maryland, dedicated to the welfare of people with epilepsy and seizure disorders. The foundation was established in 196 ...
, and Leukemia & Lymphoma Society
The Leukemia & Lymphoma Society (LLS), a 501(c)(3) charitable organization founded in 1949, is the largest voluntary health organization dedicated to fighting blood cancer in the world. The LLS's mission is to cure leukemia, lymphoma, Hodgkin's l ...
.
Organizations that oppose the legalization of medical cannabis include the American Academy of Pediatrics and American Psychiatric Association
The American Psychiatric Association (APA) is the main professional organization of psychiatrists and trainee psychiatrists in the United States, and the largest psychiatric organization in the world. It has more than 37,000 members are involv ...
. However, the AAP also supports rescheduling for the purpose of facilitating research.
The American Medical Association
The American Medical Association (AMA) is a professional association and lobbying group of physicians and medical students. Founded in 1847, it is headquartered in Chicago, Illinois. Membership was approximately 240,000 in 2016.
The AMA's sta ...
and American College of Physicians
The American College of Physicians (ACP) is a national organization of internists, who specialize in the diagnosis, treatment, and care of adults.Sokanu "What is an Internist?" Retrieved October 20, 2014 With 161,000 members, ACP is the largest ...
do not take a position on the legalization of medical cannabis, but have called for the Schedule I classification to be reviewed. The American Academy of Family Physicians and American Society of Addiction Medicine
The American Society of Addiction Medicine (ASAM), founded in 1954, is a professional medical society representing over 6,000 physicians, clinicians and associated professionals in the field of addiction medicine. ASAM is dedicated to increasing ...
also do not take a position, but do support rescheduling to better facilitate research. The American Heart Association says that "many of the concerning health implications of cannabis include cardiovascular diseases" but that it supports rescheduling to allow "more nuanced ... marijuana legislation and regulation" and to "reflect the existing science behind cannabis". The American Cancer Society and American Psychological Association
The American Psychological Association (APA) is the largest scientific and professional organization of psychologists in the United States, with over 133,000 members, including scientists, educators, clinicians, consultants, and students. It ha ...
have noted the obstacles that exist for conducting research on cannabis, and have called on the federal government to better enable scientific study of the drug.
Cancer Research UK
Cancer Research UK (CRUK) is the world's largest independent cancer research organization. It is registered as a charity in the United Kingdom and Isle of Man, and was formed on 4 February 2002 by the merger of The Cancer Research Campaign and t ...
say that while cannabis is being studied for therapeutic potential, "claims that there is solid "proof" that cannabis or cannabinoids can cure cancer is highly misleading to patients and their families, and builds a false picture of the state of progress in this area".
Recreational use
The authors of a report on a 2011 survey of medical cannabis users say that critics have suggested that some users "game the system" to obtain medical cannabis ostensibly for treatment of a condition, but then use it for nonmedical purposes – though the truth of this claim is hard to measure. The report authors suggested rather that medical cannabis users occupied a "continuum" between medical and nonmedical use.
Brand names
In the US, the FDA has approved two oral cannabinoids for use as medicine: dronabinol
The International Nonproprietary Name Dronabinol, also known as delta-9-tetrahydrocannabinol, or under the trade names Marinol, Syndros, Reduvo and Adversa, is a generic name for the molecule of delta-9-tetrahydrocannabinol in the pharmaceutic ...
and nabilone
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 ...
. Dronabinol, synthetic THC, is listed as Schedule II. Nabilone, a synthetic cannabinoid, is also Schedule II, indicating high potential for side effects and addiction. Both received approval for sale in the US in 1985, under the brand names Marinol and Cesamet. Nabiximols
Nabiximols (USAN, trade 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 blad ...
, an oromucosal spray derived from two strains of ''Cannabis sativa'' and containing THC and CBD, is not approved in the United States, but is approved in several European countries, Canada, and New Zealand as of 2013. As of 2018, medical marijuana in Canada is being legally distributed to registered patients in bud, drops and capsule forms by such companies as Canopy Growth Corp. and Aurora Cannabis
Aurora Cannabis Inc. is a Canadian licensed cannabis producer, headquartered in Edmonton. It trades on the Toronto Stock Exchange and Nasdaq as ACB. As of late September 2018, Aurora Cannabis had eight licensed production facilities, five sales ...
.
As an antiemetic
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 m ...
, these medications are usually used when conventional treatment for nausea and vomiting associated with cancer chemotherapy fail to work.
Nabiximols
Nabiximols (USAN, trade 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 blad ...
is used for treatment of spasticity associated with MS when other therapies have not worked, and when an initial trial demonstrates "meaningful improvement". Trials for FDA approval in the US are underway. It is also approved in several European countries for overactive bladder and vomiting
Vomiting (also known as emesis and throwing up) is the involuntary, forceful expulsion of the contents of one's stomach through the mouth and sometimes the nose.
Vomiting can be the result of ailments like food poisoning, gastroenteri ...
. When sold under the trade name Sativex as a mouth spray, the prescribed daily dose in Sweden delivers a maximum of 32.4 mg of THC
Tetrahydrocannabinol (THC) 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' ...
and 30 mg of CBD; mild to moderate dizziness is common during the first few weeks.
Relative to inhaled consumption, peak concentration of oral THC is delayed, and it may be difficult to determine optimal dosage because of variability in patient absorption.
In 1964, Albert Lockhart and Manley West began studying the health effects of traditional cannabis use in Jamaican communities. They developed, and in 1987 gained permission to market, the pharmaceutical "Canasol", one of the first cannabis extracts.
Research
Medical cannabis research includes any medical research on using cannabis
''Cannabis'' () is a genus of flowering plants in the family Cannabaceae. The number of species within the genus is disputed. Three species may be recognized: '' Cannabis sativa'', '' C. indica'', and '' C. ruderalis''. Alternative ...
as a treatment for any medical condition
A disease is a particular abnormal condition that negatively affects the structure or function of all or part of an organism, and that is not immediately due to any external injury. Diseases are often known to be medical conditions that a ...
. For reasons including increased popular support of cannabis use, a trend of cannabis legalization, and the perception of medical usefulness, more scientists are doing medical cannabis research. Medical cannabis is unusually broad as a treatment for many conditions, each of which has its own state of research. Similarly, various countries conduct and respond to medical cannabis research in different ways.
See also
* Charlotte's Web (cannabis)
* Chinese herbology
Chinese herbology () is the theory of traditional Chinese herbal therapy, which accounts for the majority of treatments in traditional Chinese medicine (TCM). A ''Nature'' editorial described TCM as "fraught with pseudoscience", and said that t ...
* Tilden's Extract
References
Further reading
*
External links
* , links to websites about medical cannabis
Information on Cannabis and Cannabinoids
from the U.S. National Cancer Institute
The National Cancer Institute (NCI) coordinates the United States National Cancer Program and is part of the National Institutes of Health (NIH), which is one of eleven agencies that are part of the U.S. Department of Health and Human Services. ...
Information on cannabis (marihuana, marijuana) and the cannabinoids
from Health Canada
The Center for Medicinal Cannabis Research of the University of California
''Medical Marijuana''
– a 2014–2015 three-part CNN
CNN (Cable News Network) is a multinational cable news channel headquartered in Atlanta, Georgia, U.S. Founded in 1980 by American media proprietor Ted Turner and Reese Schonfeld as a 24-hour cable news channel, and presently owned by ...
documentary produced by Sanjay Gupta
Sanjay Gupta (born October 23, 1969) is an American neurosurgeon, medical reporter, and writer. He serves as associate chief of the neurosurgery service at Grady Memorial Hospital in Atlanta, Georgia, associate professor of neurosurgery at t ...
*
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