What does "therapeutic use of cannabis" mean?
The therapeutic use of cannabis through history:
Cannabis has been used medicinally since at least 2900 BC in China, where it was prescribed for a range of conditions, including pain and chronic illness.
Its use spread to other regions — India, the Middle East and Europe — where it was valued for its analgesic, sedative and anti-inflammatory properties.
In its 1889 edition, the respected Merck Manual recommended it for the treatment of chronic pain, migraine and seizures, among many other conditions. Cannabis was considered "one of the most valuable medicines we possess, when pure and administered carefully". The article appeared in The Lancet (1887), signed by J. R. Reynolds, personal physician to Queen Victoria.
Prohibition:
The prohibition of cannabis in the United States in 1937, through the Marihuana Tax Act, was the result of various social, economic and moral factors. It had nothing to do with medical or clinical reasons.
Treating cannabis as a "substance with a high potential for abuse, no therapeutic value and whose use poses serious risks to health" in the UN drug conventions is not based on medical, clinical, pharmacological or toxicological criteria.
Through the second half of the twentieth century the clinical trial became the standard method for testing the efficacy and safety of medicines. In these trials the drug under study is compared against a placebo to obtain objective results through the scientific method. Cannabis, however, was barely subjected to such studies, because of a prior assumption — grounded more in moral judgement than in scientific evidence — that it had no therapeutic value. Even so, medicines were developed and approved to treat the very conditions for which cannabis had traditionally been used. Curiously, some of those medicines, such as the barbiturates, turned out to carry greater pharmacological risks than cannabis.
The endocannabinoid system ("Cannabis takes its revenge")
Cannabinoids such as delta-9-tetrahydrocannabinol (delta-THC) and cannabidiol (CBD) are chiefly responsible for the plant’s biological effects.
Until the 1990s the mechanism by which cannabinoids acted inside the body was unknown. Most scientists held that cannabis simply crossed cell membranes, producing non-specific effects.
Since the 1990s an endocannabinoid system has been characterised, present in all vertebrates and made up of:
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Receptors:
- CB-1 receptors are found in the central nervous system (basal ganglia, the brain’s limbic system and the cerebellum), as well as in the testes and ovaries.
- CB-2 receptors appear on immune system cells, expressed in large numbers in the spleen.
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Endogenous cannabinoids:
- The body physiologically produces its own cannabinoids (endocannabinoids: anandamide and 2-arachidonoylglycerol). These are the molecules that bind to the CB-1 and CB-2 receptors.
The plant’s cannabinoids — delta-9-tetrahydrocannabinol (delta-THC) and cannabidiol (CBD) — bind in the body to the receptors of the endocannabinoid system.
So do the dozens of cannabinoids expressed in lower concentrations across different plant varieties.
The cannabis plant also contains essential oils, phenols, terpenes and fatty acids which, in some cases, have proven biological effects.
What the endocannabinoid system does
The endocannabinoid system (ECS) plays a crucial part in maintaining homeostasis in the human body, regulating a wide range of biological functions. Here is a detailed list of them:
Functions and potential applications of the endocannabinoid system (ECS)
| Function | Description |
|---|---|
| Pain modulation | Regulates the sensation of pain, offering natural relief through interaction with the cannabinoid receptors. |
| Control of nausea and vomiting | Essential in regulating these symptoms, particularly during treatments such as chemotherapy. |
| Movement coordination | Crucial for agility and fluid movement, affecting bodily coordination. |
| Regulation of learning and memory | Influences the capacity for learning, memory and emotion, affecting how we process and store information. |
| Regulation of blood pressure and heart rate | Maintains cardiovascular balance, contributing to the control of these measures. |
| Control of cancer cell growth | Through the CB-2 receptors, it can influence the immune system in fighting tumour cells. |
| Stimulation of the immune system | Strengthens the body’s defences against disease, including the destruction of tumour cells. |
| Appetite regulation | Affects hunger and satiety, with implications for eating disorders and obesity. |
| Neuronal protection | Protects neurons against damage, relevant in neurodegenerative disease. |
| Sleep regulation | Contributes to the quality and length of night-time rest, regulating sleep cycles. |
| Response to stress and anxiety | Modulates the stress response and has anxiolytic effects, helping in the management of anxiety. |
| Inflammatory processes | Regulates inflammation, offering therapeutic potential in chronic inflammatory disease. |
| Skin health | Influences the function and health of the skin, regulating sebum production and controlling conditions such as acne. |
|
Fertility and reproduction |
Affects fertility and processes in the reproductive system of both sexes. |
My experience
Individual advice for patients who use cannabis, or are considering using it therapeutically:
Between 2005 and 2023 I have seen more than 350 patients seeking objective, high-quality, scientifically grounded information on the practical handling of cannabis and cannabinoids in different conditions.
Some of the things that advice covers:
- The condition being treated: the strength of the available scientific evidence on the efficacy and safety of cannabis varies from one disease to another. In some conditions (multiple sclerosis, neuropathic pain and others) the efficacy of cannabinoids is well established,
while in others it is weaker. - Previous experience with the substance: cannabis produces an altered state of consciousness that some people find pleasant and others do not. In people who know its effects and have some experience, therapeutic benefit is more likely.
- Beliefs and attitudes: in any drug treatment it matters to test what the patient knows, believes and thinks against reality. The social baggage around cannabis makes this particularly important. Some beliefs about cannabis are not backed by science — for instance, that cannabis has no therapeutic properties because it is an illegal drug, or that it is better than other medicines because it is natural.
- Therapeutic alternatives: the fact that cannabis can be effective in certain conditions does not make it the best treatment in every case. Depending on the condition and the patient’s characteristics, other medicines may work better.
- Route of administration: smoking is the most common route among cannabis users, but it has potential negative effects on health. Correct use of an approved vaporiser can instead achieve sufficient cannabinoid concentrations while avoiding the adverse effects of combustion. In some cases the oral route (tinctures, oils or extracts in other carriers) may be appropriate, although this route
has drawbacks of its own, due to variable absorption and a greater chance of acute intoxication. - Variety and potency of the plant: different species of Cannabis sativa or Cannabis indica can contain very different amounts of the plant’s various cannabinoids. Many commercial varieties are selected to maximise the mental effects of cannabis (with very high THC content) and may not be suitable for
therapeutic use. - Adverse effects: like any other medicine, cannabis can produce unwanted effects (low blood pressure, anxiety, dizziness, increased appetite, effects on memory and so on) that need to be taken into account.
- Contraindications and drug interactions: certain diseases or conditions contraindicate the use of cannabis. Pregnancy, psychiatric illness or
hepatitis C virus (HCV) infection may all be circumstances that make its use inadvisable. - Some commonly used medicines can also produce adverse effects.
- Legal aspects: selling cannabis derivatives is punishable under the Spanish Criminal Code, and possessing them in public places for consumption can lead to administrative penalties (fines).
Advice to cannabis associations and clubs
Training for the staff of cannabis associations and clubs on basic health matters (Energy Control, ICEERS).
Work with associations interested in offering a therapeutic cannabis service. Drafting of a protocol and good-practice guide.
Between 2012 and 2023 I have worked with 12 associations across Spain: Manali, El Oso y el Cogollo, Charas, IKAP, La Flora, Castelló Cannabis Club, Club de Autocultivo Terapéutico de Aragón, Private Cannabis Club, Planeta Chamberí, Assonabis, The Haze Crew and the Federation of Cannabis Associations.