Medical cannabis

Cannabis (marijuana weed) or Cannabinoids are active chemical compounds derived from dried leaves, flowers, stems and seeds of Cannabis sativa or Cannabis indica plant, which contain drug-like properties. 

According to WHO, Cannabis is the most widely cultivated, trafficked and abused drug. About 2.5% of the world population, that is, 147 million people, consume cannabis worldwide.

Cannabis is widely used for medicinal and recreational purposes. When used for medicinal purposes, it is called Medical Cannabis. It is used to manage chronic pain, cancer pain, trauma pain, neuropathic pain, psychiatric disorders, seizures, and anxiety. 

In this article, we’ll explore the types, mechanisms, pros and cons of medical cannabis. 

Relevance to chronic pain

A pain that lasts longer than 3 months is called Chronic Pain. It is seen in various conditions such as:¹

• Autoimmune disorders (conditions in which the body attacks its cells and tissues) like rheumatoid arthritis, fibromyalgia, and gout
• Nerve damage like postherpetic neuralgia, diabetic neuropathy, and sciatica 
• Pain due to cancer, tumour, or fracture
• Chronic lower back pain or myofascial pain

Chronic pain is a major issue throughout the world which is poorly managed. It affects people of all ages, and the prevalence (the number of cases at a given time) increases with age.⁴

It can deeply impact people with the above conditions. It causes physical discomfort and affects mental well-being, productivity, mobility, social life, and sleep. 

Hence, exploring effective pain relief options for a better quality of life is crucial. 

Existing treatment options

Let’s take a look at the existing treatment options and their drawbacks:¹

• Non-steroidal anti-inflammatory drugs (NSAIDs): These drugs reduce pain, inflammation, and fever
  • Drawback: It is the first-line (initial treatment) drug to manage chronic pain. However, it may not provide adequate pain relief sometimes. Its use is cautioned in people with heart disease, heart attack, damaged kidneys, or stomach ulcers
• Opioids: Opioids are a class of drugs which are derived from the opium poppy plant or made in laboratories. It is most commonly used for pain relief. It may also be used to treat cough or diarrhoea
  • Drawback: Opioids are highly addictive and, hence, are used only for the short term. It is one of the most abused drugs
• Non-pharmacological therapies: These are the treatment methods that do not involve drugs. These include physical therapy, heat and cold therapy, biofeedback, acupuncture, and electrical stimulation therapies
  • Drawback: Such therapies require regular sessions, which may not be feasible. Also, it may not provide adequate relief in case of intense and debilitating pain

Mechanism of medical cannabis in pain relief

Let’s understand the mechanism of medical cannabis and its role in regulating pain, mood, and inflammation.

Cannabinoids and the cannabinoid system

Cannabis contains more than 550 different chemical compounds, out of which about 100 compounds are Phytocannabinoids.² Two main types of phytocannabinoids found in cannabis that act on the brain are:

• Tetrahydrocannabinol (THC): psychoactive (drugs affecting mental processes) properties, pain relief
• Cannabidiol (CBD): non-psychoactive, anti-inflammatory, and pain-relieving

The endocannabinoid system (ECS) is a natural network of lipids and their receptors throughout the body. It alters nervous system activity through chemical or electrical stimulation.
It regulates human physiological, behavioural, immunological and metabolic functions.³ In simple words, it affects mood, pain, sleep, and the body’s defence responses. 

THC and CBD bind to these ECS receptors (CB1 and CB2) and alter pain perception, affect mood, and reduce inflammation. 

Pros of using medical cannabis for chronic pain relief

Medical Cannabis has several therapeutic effects, such as:

Effective pain reduction

Using medical cannabis is a great option to reduce pain and soothe the patient. It provides relief and calms the patient. 

According to a systematic review, cannabinoids are an effective and safe treatment option for chronic pain, such as neuropathic pain.⁴

Reduced opioid use

Long-term use of opioids may result in addiction and dependence on the drug. According to WHO, about 80% of 600,000 deaths due to drugs in 2019 involved the use of opioids. Nearly 125,000 people died of opioid overuse.⁶

Opioid dependence is characterised by a strong internal drive to use opioids. An overdose of opioids shows 3 signs: pinpoint pupils, loss of consciousness, and difficulty breathing. 

However, with medical cannabis, there is a lower risk of drug overdose and dependency. It serves as an effective alternative to opioids. 

Reduced side effects

Opioids are known to have detrimental side effects on respiration. It causes slow, shallow and irregular breathing, which may result in death if not monitored regularly.⁵ This condition is called Respiratory Depression. Medical cannabis does not show any such side effects. 

Anti-inflammatory benefits

Cannabinoids block the inflammatory pathways and provide relief in inflammatory conditions. It could be beneficial for the treatment of Alzheimer’s disease, Huntington’s disease, and Parkinsonism.⁷

Improved sleep and relaxation

In a study, about 80% of research participants cited sleep and relaxation as the most common reasons to use cannabinoids.⁸ Studies have reported that people feel more refreshed, focused, and efficient in the morning after using cannabis for sleep the night before.⁹

THC has sedating properties. It reduces the time it takes to fall asleep and increases the amount of deep sleep. CBD has a calming effect, relaxing the mind before sleep. 

Cons of using medical cannabis for chronic pain relief

While medical cannabis has therapeutic value, it can also produce the following detrimental effects if used for a long time or at a high dose:

Psychoactive side effects

Certain psychoactive side effects induced by cannabis are:

• Drowsiness: sleepiness
• Dizziness: feeling weak or unsteady
• Dysphoria: a state of unease and dissatisfaction
• Mild euphoria: a state of happiness and excitement
• Paranoia: an irrational and persistent feeling that people do not like you or want to harm you

Other Side Effects include:¹⁰

• Dry mouth
• Anxiety due to dysphoria
• Mild panic attacks
• Weight gain due to increased appetite
• Cardiovascular diseases

Risk of dependency

THC is a psychoactive substance which has the potential for psychological dependency. Although the risk for cannabis dependence is less compared to opioids, it is not negligible. 

Cognitive impairment

Various studies indicate cognitive impairment, meaning reduced intellectual capability to think, learn, and understand things.¹¹ It negatively affects memory and focusing abilities in young adults.¹¹

Respiratory health concerns

According to WHO’s report Cannabis: A Health Perspective and Research Agenda, cannabis smoke and tobacco smoke are very similar except for the presence of nicotine in tobacco smoke. 

Smoked cannabis can cause various lung issues, such as:

• Shortness of breath
• Reduced airflow
• Lung irritation
• Lung infections
• Bronchitis (Inflammation of the lung airways)

Legal and accessibility issues

In earlier times, marijuana was used as folk medicine. Later, due to its use for non-medical purposes, marijuana was considered a substance for abuse and outlawed in various places.¹²

Its use should always comply with state and federal laws. The varying legal status of medical cannabis globally makes access challenging for some people. 

Read more here: Countries Where Weed Is Illegal 2024

Insufficient research

Due to the lack of large-scale studies on the long-term effects of cannabis on pain management, the FDA has not recognised or approved cannabis or marijuana as a medicine. It is a Schedule 1 drug, which means there is no currently accepted medical use, and it has a high potential for abuse. 

Read more here: FDA Regulation of Cannabis and Cannabis-Derived Products, Including Cannabidiol (CBD)

Ethical concerns

The reputation of cannabis as a substance of abuse creates potential stigma or workplace discrimination related to medical cannabis use. 

Healthcare professionals are reluctant to prescribe it due to the risk of developing addiction, dependency, and abuse in patients. 

Types of cannabis products for pain management

The method of cannabis administration impacts the onset, intensity, and duration of the effects. 

Inhalation (smoking or vaping)

Two of the most common methods of cannabis administration are inhalation via smoking or vaporisation. Two trials showed that smoked cannabis effectively reduced nerve pain due to HIV.⁴

It provides quick relief but poses potential respiratory risks, as discussed above.

Edibles and tinctures

Consuming cannabis edibles is the third most common way of administration. It has a slower onset but provides longer-lasting relief. 

Topical applications

Applying cannabis in the form of cream, ointment or paste on the area with localised pain reduces pain, inflammation, and itching and promotes wound healing. It does not cause any psychoactive effects.¹³

Capsules and tablets

Cannabis capsules and tablets provide controlled and precise dosing. It is beneficial for chronic pain, sleep issues and anxiety. 

The most commonly used capsules are THC capsules and CBD capsules. 

Certain well-known cannabis drugs are nabiximols, dronabinol, and nabilone capsules. 

Factors to consider when using medical cannabis for pain relief

The use of medical cannabis for pain relief is a controversial topic due to inadequate research and data. It is important to consider the following factors when using medical cannabis for pain relief:

Dosage and product choice

Starting with low doses prevents intense adverse effects and ensures a safe and effective treatment. If the initial dose is high, the patient may require progressively larger doses for relief. 

Low doses help find the minimum dose required to achieve pain relief and hence reduce high tolerance buildup. 

Smoking or vaping cannabis should be avoided due to the potential risk for respiratory damage. 

Professional guidance

Consulting a healthcare provider is a must when using cannabis for pain relief. It should be done under constant guidance and supervision. 

Monitoring for side effects

It is important to monitor side effects regularly to achieve optimal relief without excessive psychoactive effects.

Summary

Cannabis or cannabinoids are psychoactive chemical compounds found in dried leaves, stems, flowers and seeds of Cannabis sativa or Cannabis indica plants. 

Medically, cannabis is used for HIV AIDS-related problems, chronic pain, depression, anxiety, menstrual cramps, and migraine. The pros and cons of using medical cannabis for chronic pain relief depend upon the dose, product type and individual approach. The pros involve effective pain relief, reduced opioid use and side effects. The cons involve cognitive impairment, respiratory health issues, and legal and accessibility issues. There is a need for further studies to provide clarity on long-term safety, optimal dosages, and product types. The bottom line is to weigh options carefully before trying medical cannabis. It is a great option to relieve pain, but not the most preferred method.