Chronic pain is a common cause of missed work days, deteriorating mental health, and disability all over the world. Data shows that chronic pain affects every 1 in 5 individuals in the United States and is associated with medical and disability costs of almost $560 billion. (1) Individuals with chronic pain report signs of physical, emotional, and mental stress that interfere with their quality of life and general wellbeing. Hence, the treatment suggested for chronic pain is also usually multifaceted, including pharmacological and non-pharmacological approaches. Over the recent years, Medical Cannabis has gained attention as a treatment option for chronic pain. This is due to the higher number of studies proving the analgesic effects of Cannabis, more states legalizing treatment using marijuana, and greater awareness amongst the general population.
What is Medical Cannabis?
Cannabis includes a group of different compounds that acts in the cannabinoid receptors inside the body. (2) The compounds that are found to exist in the highest concentrations are Cannabidiol (CBD) and Tetrahydrocannabinol (THC).
- THC: THC is responsible for the psychoactive effects associated with marijuana. These commonlyinclude Euphoria and Psychosis.
- CBD: CBD is responsible for the anti-anxiety and anti-psychoactive effects experienced byindividuals when they consume marijuana.
The overall therapeutic potential of Cannabis depends on the ratio of THC to CBD found in it. This is also what differentiated recreational Cannabis from medicinal Cannabis. While recreational Cannabis has a higher THC to CBD ratio, medicinal Cannabis contains higher levels of CBD, so the THC to CBD ratio is lower. (3)
Once Cannabis is consumed, it acts on the endocannabinoid receptors in the body. These receptors include the cannabinoid Type 1 Receptors and cannabinoid type 2 receptors. These are located all over the body, and activation of different receptors can have different effects on the body.
Cannabinoid 1 Receptors
The CB1 receptors or the Cannabinoid Receptors Type 1 are mainly found in the central nervous system, which is made up of the brain and spinal cord. They are associated with the psychotropic effects of Cannabis. The CB1 receptors can also affect the way an individual perceives pain. They do this by signaling the sensations of pain to the brain through the spinal cord. These receptors may also affect the individual’s memory, emotions, and sense of reward.
Cannabinoid 2 Receptors
Cannabinoid Receptors Type 2 have an anti-inflammatory effect on the body. Due to their association with the immune system, they also play an important role in relaying the sensations of pain to the brain. These receptors are mainly found in the body’s immune cells and outer tissues. They are also found in the Central Nervous system, but the level is much lower than those seen in the CB1 receptors.
The Effectiveness Of Medical Cannabis In Treating Chronic Pain
Marijuana was first started to be used for medicinal reasons almost 5000 years ago. Chinese experts initially used it to allow pain relief to mothers after childbirth. It was also given to patients with Malaria, Rheumatic pain, and constipation. (4) Its use became more common in the 19th and 20th centuries, as stated by the United States Pharmacopeia. The state that first legalized marijuana in the United States was California in the year 1996. (5)
Over the past few years, numerous studies investigating the effectiveness of Medical Cannabis for chronic pain have been published – the majority of which have found it to be highly effective. For example, one such study conducted on individuals with chronic pain showed a 64% reduction in pain after using medical marijuana. (6) The study participants also reported finding improvement in their quality of life and lesser side effects compared to other long-term therapies for chronic pain.
The lack of adverse effects associated with Medical Marijuana as compared to Opioids has also made it more favorable amongst the population over the past few years. While opioid use is associated with major side effects like respiratory depression, marijuana can prove to be a highly effective alternative. This was further investigated in a study conducted to analyze the outcomes of marijuana compared to opioids. The results of the study showed a 17% reduction in opioid-associated deaths when the individuals switched to medical marijuana. (7)
The Appropriate Dose Of Medical Marijuana For Chronic Pain
The most appropriate dose of medical marijuana for the treatment of chronic pain has been a topic of discussion amongst experts all over the world. The majority of the experts believe that the doses of THC should start from 2.5 milligrams, which are slowly built up every two to seven days until a maximum concentration of 40 milligrams is reached. If this dosage is adequate to provide pain relief from chronic pain, the patient should consult a medical cannabis expert who can guide them regarding the dose that may be safe for them. (8)
How Routes of Administration For Medical Cannabis
One of the most popular ways medical marijuana may be taken is through inhaling it. This allows the compounds to cross the blood-brain barrier directly and show their effects. This may be particularly beneficial for treating neuropathic pains and centralized pain disorders like fibromyalgia. The impact of this may be felt within 2 minutes and may last for up to 4 hours.
While the effects of taking medical marijuana in the form of edibles are similar to that of inhaling it, they may take a longer time. There are wide varieties of edible Cannabis in the market, and when consumed, they pass through the digestive tract like any other food or drink consumed does. Hence, these effects will be felt after a couple of hours, once the digestion and absorption of the compounds have taken place. In addition, experts believe that the interaction of Cannabis with the microbiota in the digestive tract can also lead to added beneficial effects on the digestive system. However, as the effects as not felt immediately, the individuals are at risk of overcoming it. Therefore, while recommending medical marijuana, the doctor should educate the patient regarding the correct way of taking marijuana and the limit that should not be exceeded. Individuals with chronic pain may be recommended to begin with 1 to 5 mg of THC in the form of edibles.
Moreover, data suggests that the intake of Cannabis in edibles lasts longer than inhaling it. Edibles are also available in the form of oils, which can be taken orally. They can be placed under the tongue, from where it is quickly absorbed into the blood. Moreover, taking tinctures may be preferred by individuals who want to have more control over their intake of Cannabis, as it can be measured precisely. Topical Topical Cannabis is most commonly recommended for chronic pain and inflammation that is localized in nature. This means that the pain is felt only at a particular area or point in the body. Hence the Cannabis that is applied topically is not absorbed into the systemic blood circulation and does not affect the individual’s mental status. Topical formulas of marijuana may be available in the form of creams, oils, lotions, and salves.
Potential Risk and Side Effects
- The potential adverse effects associated with Cannabis use include:
- A risk for cannabis dependence
- Breathing problems – particularly in Individuals with breathing disorders like Asthma
- Feeling lightheaded or dizzy
- Moderate Addiction potential
- Delayed reaction times
- Unable to concentrate
- Loss of memory (9)
- Increased heart rate
- Withdrawal Symptoms
- Dry Mouth
Some individuals may also experience more serious adverse effects. These were investigated in a systemic review which showed minor adverse effects in 51% of included studies and more serious adverse effects in 36% of the studies. The remaining 15% of the studies did not define the extent of the adverse effects. The serious side effects associated with Cannabis use may include:
- Urinary Tract Infections
- Dysphoric Reactions
- Psychotic Symptoms (10)
The Bottom Line
Numerous studies have proved the benefits of Cannabis for Chronic pain. Data shows it to be as effective as opioids for pain relief, which are now commonly recommended by health experts. Moreover, the side effects associated with Cannabis are minimal in nature, especially when compared to the side effects of long-term therapy with opioids. It is now available in different forms, which allow multiple routes of administration. These include inhalation, oral intake, and topical application. While Inhalation of medical Marijuana may provide the quickest form of pain relief, its effects don’t last as long as those seen with oral forms of marijuana. The topical applications are effective for localized pain relief, as they don’t reach the systemic blood circulation and don’t affect the mental status. The initial doses of marijuana for medical purposes should be slow and then slowly built up. It is advised to consult the doctor regarding the risks and benefits associated with Marijuana use. The individual should also make sure that the marijuana they consume is availed through a roper and legal channel.
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