CBD for Sciatica | CBDnerds
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CBD is a new and relatively understudied treatment. Though its anti-inflammatory and anti-hyperalgesic effects are documented, further strong research is needed to establish it as a conventional treatment for sciatica.
The use of CBD in sciatica is a relatively new area of research. Though the efficacy of CBD is established in animal models, studies with more rigorous methodology are required.
Anti-hyperalgesic and anti-inflammatory effects of CBD are evident in animal and human studies. It can be used as a potential treatment option for sciatic or sciatic nerve injury.
CBD for Sciatica: Can It Help? (June 2021)
Cannabidiol (CBD) is being looked upon as a potential treatment for sciatica.
Analgesic, anti-inflammatory properties of CBD, and limited negative side effect profile highlight its potential in sciatica treatment. Despite the benefits, CBD oil usage is a new and relatively understudied treatment.
People choose CBD products as an alternative to routine OTC pain relief drugs, probably due to the lower risk of addiction.
The efficacy of cannabis-based medicines in pain management is well established, and so are CBD's therapeutic effects.1
Limited research supports the use of CBD in managing sciatic pain and alleviating the after-effects of sciatic nerve injury.
This article provides glimpses of research on CBD for sciatica, including its effect, mode of action, dosing, and more.
Sciatica, a condition commonly described by radiating leg pain, is a cause of severe discomfort and functional limitation.2
It affects many people; so much that it is diagnosed in almost 5%-10% of patients with low back pain.3 In the general population, the annual prevalence of disc-related sciatica is around 2.2%.3
Increased risk for sciatica is seen with increasing age, height, mental stress, cigarette smoking, and vibration exposure.3
In general, pain-related disability in acute sciatica could be effectively treated with non-surgical interventions. In most patients, the prognosis is good; however, a substantial proportion of patients (as high as ~30%) complain of pain for one year or longer.3
Pain management and maintaining the individual's functionality while the compression/ inflammation subsides are primary targets in sciatica treatment.2
Sciatica Symptoms and Pathology
Symptoms of sciatica can be distressing. They can affect the daily life and productivity of the individual. Leg pain worse than back pain or pain below the knee raises suspicion of sciatica.
People confuse sciatica with non-specific low back pain. Hence, distinguishing signs and symptoms of sciatica is very important.
Distinguishing characteristics of sciatica include:3
- Unilateral leg pain greater than low back pain
- Pain radiating to foot or toes
- Numbness and paraesthesia in the same distribution
- The straight leg raising test induces more leg pain
- Localized neurology -that is, limited to one nerve root
Sciatica is caused by compression of the nerve root and resultant inflammation. The commonest cause being disc herniation because of age-related degenerative changes. Other causes include narrowing of the spaces within the spine because of cysts, tumors, or extraspinal pathology.2
Can CBD Help with Sciatica?
CBD is commonly used in pain management. Hence, it could also help in the treatment of pain in sciatic nerve injury. However, whether it will have any effect on disease pathology is not clear.
Neuropathic pain caused by disease or nerve injury is difficult to treat clinically. Conventional medications provide limited relief from chronic neuropathic pain. Additionally, their safety is challenged by their debilitating side effects.4
Overall the disease burden increases owing to the complexity of symptoms, poor treatment outcomes, and difficult treatment decisions.5 Chronic neuropathic pain, thus, can take troll of individual's life.
Treatment with cannabis extract has shown promising results. One of the animal studies has demonstrated a significant reduction in thermal hyperalgesia (increased pain sensitivity) and mechanical allodynia (when you feel pain from stimuli that don't normally cause pain) using cannabis extract.6
This effect is favorable in managing chronic constriction injury of the sciatic nerve and is caused by CBD and low Δ9-tetrahydrocannabinol (THC).4
Another study on neuropathic and inflammatory pain rat models highlights CBD's role in reversing thermal and mechanical hyperalgesia, suggesting CBD's ability to improve established disease pathology.7
These and other studies oblige CBD as a therapeutic alternative in neuropathies like sciatica.
How CBD Works?
CBD acts through transient receptor potential vanilloid receptor 1 (TRPV1). CBD is a potent TRPV1 agonist (a compound that can bind to and activate a receptor).8
Inflammation and nerve injury results in up-regulation of TRPV1 receptors, contributing to inflammatory and neuropathic hyperalgesia. CBD desensitizes this receptor and thus reduces the pain.7 Also, unlike natural agonists of TRPV1 receptor, CBD does not induce pain after acute administration.7
Repeated doses of CBD could significantly reduce thermal and mechanical hyperalgesia, which typically develops after sciatic nerve injury.7
Thus, CBD could be effectively used as an anti-hyperalgesic in persistent pain management.7
CBD also works as a potent anti-oxidant.7 Neuroinflammation after nerve injury causes an increase in the formation of several reactive free radicals and a consequent rise in lipid peroxide levels.7
Chronic inflammation and neuropathic pathologies in rats and humans cause a rise in glutathione-dependent enzymes, probably to deal with increased levels of lipid peroxides.7
Treatment with CBD curtails the rise in lipid peroxide levels and also inhibits the enzymatic activity of glutathione peroxidase and glutathione reductase in pathological tissue, ultimately limiting neuroinflammation.7
What Does the Research Say?
There is a growing trend of CBD for sciatica management. Though the research is mainly at the level of animal studies, limited human data is available in favor of full spectrum hemp extract.
A 2006 study evaluated the therapeutic potential of CBD on neuropathic and inflammatory pain in rats. In both the models, treatment with CBD resulted in reduced hyperalgesia to thermal and mechanical stimuli and thus indicated a potential of CBD in the treatment of chronic painful states.7
Another 2013 study has investigated the neuroprotective potential of CBD. Neonatal rats who underwent sciatic nerve axotomy (cutting a neuro's axon), when treated with CBD, demonstrated motor and sensory neuron rescue following treatment with CBD.9
The CBD-treated group revealed 30% greater synaptic preservation within the spinal cord when compared to the non-treated group. These neuroprotective properties of CBD could be promising for future clinical use.9
Meanwhile, a 2016 study in humans evaluated the effect of medicinal cannabis (at a fixed dosage of 20 grams/ month) in a cohort of 46 patients suffering from sciatica for a minimum of 12 months. 10 Short-term usages of smoked medicinal cannabis lead to an improvement in physical as well as mental function. Also, pain levels decreased in chronic back pain sufferers.10
One animal study carried out in 2019 investigated the role of crude Cannabis sativa L. leaf powder on functional recovery in mouse models subjected to traumatic sciatic nerve injury.11 Significant improvement in motor functions, restoration of muscle mass, and elevated hemoglobin levels were observed in mice treated with a dose of 200 mg/kg orally, indicating accelerated motor function recovery after treatment.11
Meanwhile, one more animal study in 2019 highlights the potential of cannabinoids on long-term relief from chronic pain states. In this sciatic nerve injury mouse model, orally administered CBD resulted in a significant reduction of allodynia up to 3 weeks post-surgery. An analgesic trend was also observed for CBD.12
A recent animal study in 2020 reports the use of cannabinoid in rats for the treatment of peripheral neuropathic injury due to sciatic nerve cuff. 13 The study reports the effectiveness of CBD, THC, and also their 1:1 combination in countering aberrant peripheral sensory activity and also modulated immune response in male rats.13
Using CBD for Sciatica
Though animal models advocate oral or systemic use of CBD; for humans, CBD is used either orally or by inhalation.14 The mode of administration determines the metabolism of CBD. 15
In the majority of neuropathic pain models, CBD has been administered orally. The only human study reports the use of CBD by inhalation. Inhalation could be by smoking or to a lesser extent by vaporization.15
Inhaled CBD has advantages over oral CBD. Inhaled CBD shows a fast onset of action, rapid attainment of peak effect, and less generation of psychoactive metabolites.15
Systemic administration is another method for using CBD. Acute systemic administration of low-dose THC: CBD combination treatment has demonstrated enhanced pain-relieving action in mouse models.6
Full-spectrum CBD products are advocated considering CBD and THC's synergistic action as observed in neuropathic pain mouse model.
Transdermal application is another mode of administration of CBD and is found to improve pain in patients with peripheral neuropathy .16
How Much CBD Should I Take for Sciatica?
CBD is usually well-tolerated; however, overuse is not recommended. It's a good idea to consult a doctor before initiation of CBD.
CBD can potentially interact with other medications, and hence it should be taken as prescribed by your physician.
CBD's activity is evident in a range of doses, starting from very low to very high. CBD's anti-inflammatory and anti-oxidative effects are evident even at lower doses. At the same time, a CBD dose as high as 1500 mg per day is well tolerated.14
The anti-hyperalgesic effect of CBD is dose-dependent, a complete elimination of hyperalgesia is observed with the highest dose of 20 mg/kg. Repeated administration of CBD at this dose leads to the abolishment of hyperalgesia and restored physiological threshold. 7
Recent studies have tried modeling human CBD consumption in rodents more closely with vapor chambers or orally consumed solutions.12
Despite the evidence, it is important to understand that different administration modes may affect the efficacy of the product, and hence cautious use of CBD is essential.
Are There Any Side Effects?
CBD is generally considered safe in humans. Studies suggest that CBD does not induce changes in food intake, does not affect physiological parameters, does not alter gastrointestinal transit, and does not alter psychomotor functions.17 However, some unwanted side effects are reported on CBD use.
Short-term CBD treatment in humans shows low toxicity and mild adverse effects.18
The most commonly reported side effects include:
- Dry mouth
- Low blood pressure
- Changes in appetite/ weight
A better safety profile of CBD warrants improved patient compliance and adherence to the treatment.14
Despite the usefulness of CBD in chronic conditions, some in vivo and in vitro studies have demonstrated potential drug metabolism interactions. Adverse effects such as inhibition of hepatic drug metabolism and decreased fertilization capacity are observed.17 This calls for careful monitoring of CBD use in humans.
CBD is an emerging therapeutic option for a range of medical conditions. The efficacy of treatment in CBD for sciatica is still in the budding stage.
Animal and human studies support the anti-inflammatory and anti-hyperalgesic effects of CBD in managing sciatic nerve injury pain. CBD is not only effective in pain management but could also improve motor function recovery. It has also demonstrated a neuroprotective effect.
Using CBD is safe as most patients experience minor side effects.
Inhalation or oral administration is the most suitable method for human consumption. Amongst them, inhalation provides faster results.
CBD consumption, as advised by a physician, warrants the best outcomes.
7. Costa B et al. "The non-psychoactive cannabis constituent cannabidiol is an orally effective therapeutic agent in rat chronic inflammatory and neuropathic pain." European journal of pharmacology. 556(1-3)(2007):75-83.
8. Bisogno T et al. "Molecular targets for cannabidiol and its synthetic analogues: effect on vanilloid VR1 receptors and on the cellular uptake and enzymatic hydrolysis of anandamide." British journal of pharmacology. 134(4)(2001):845-52.
11. Aziz N et al. "Supplementation of Cannabis sativa L. leaf powder accelerates functional recovery and ameliorates haemoglobin level following an induced injury to sciatic nerve in mouse model." Pakistan journal of pharmaceutical sciences. 2 (2019):32.
13. Linher-Melville K et al. "Evaluation of the preclinical analgesic efficacy of naturally derived, orally administered oil forms of Δ9-tetrahydrocannabinol (THC), cannabidiol (CBD), and their 1: 1 combination." Plos one. 15(6)(2020):e0234176.