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will cbd oil work for neuropathy

What is neuropathy and can cannabis help?

Tingling. Burning. Shooting. Stabbing. If you suffer from neuropathic pain, these unfortunate adjectives are all too familiar.

Neuropathic pain, or neuropathy, is a catch-all term for pain caused by damage to the nervous system. It’s one of the most common forms of chronic pain, affecting one to two per cent of the population and producing feelings of weakness, numbness, tingling and burning.

“Neuropathic pain is something we see a lot in our older patients,” says Natural Care’s Director of Patient Care, Karen Newell, who is also a registered practical nurse. “It’s fairly common in seniors because they are likely to be dealing with one or more of the conditions that cause it.”

What causes neuropathic pain?

Neuropathy has many causes, including:

  • Alcoholism
  • Autoimmune diseases (including diabetes, multiple sclerosis, lupus, rheumatoid arthritis and thyroid disorders)
  • Chemotherapy treatment
  • Exposure to toxins
  • HIV
  • Injuries
  • Shingles
  • Surgery

How long does neuropathic pain last?

Neuropathic pain can come and go over the course of a day, or even come and go over weeks and months. There’s no one set path for the journey through neuropathic pain. For most, it’s a chronic companion, for some, it’s a temporary travelling partner who can be kicked to the curb.

Can cannabis help neuropathic pain?

Anecdotally, several of our patients report that cannabis helps with their neuropathic pain, but so far the evidence is mixed.

A review published in the AMA Journal of Ethics concluded that cannabis is comparably effective to the traditional agents used to treat neuropathic pain. The review looked at studies conducted with vaporized or smoked cannabis flower of low to medium THC concentration (two to nine per cent). Study subjects ranged from HIV patients dealing with neuropathy to healthy volunteers who had been purposefully injected with pain-inducing capsaicin (the ingredient that makes peppers hot).

Another review, which looked at studies conducted with a range of cannabis products – from synthetic cannabinoids, to sprays containing a mix of THC and CBD, to inhaled flower and more found “no high-quality evidence” to support the use of cannabis for neuropathic pain, citing side effects of sleepiness, dizziness and mental problems compared with placebo.

These reviews are interesting because they both draw their conclusions from a mixed bag of studies, often featuring multiple and diverse cannabis products used to treat neuropathy of multiple and diverse origins. Imagine a sommelier saying “wine never pairs with meat” or “wine always pairs with meat” and you can easily understand the problem we face in interpreting these kind of broad reviews.

Determining the right cannabis product for a specific health goal is more complicated than choosing the right wine for dinner: cannabis comes in many different strains, strengths and formats (vaporized, ingested capsules and oils, etc), and every person processes it differently, making it difficult to generate conclusive prescriptions.

Interestingly, smaller studies looking at specific products and dosages tend to generate more promising results:

A 2013 double-blind, placebo-controlled study published in the Journal of Pain found that low-dose cannabis (1.29 per cent THC or less) significantly improved neuropathic pain when compared with medium-dose and placebo cannabis. Most of the subjects in this study had already experienced poor results with conventional neuropathic pain treatments, leading its authors to conclude that “vaporized cannabis, even at low doses, may present an effective option for patients with treatment-resistant neuropathic pain.”

Similarly, a 2010 trial published in the Canadian Medical Association Journal looked at 23 patients who were assigned three different strengths of cannabis to manage post-traumatic and post-surgical neuropathic pain. The conclusion? “A single inhalation of 25 mg of 9.4% tetrahydrocannabinol herbal cannabis three times daily for five days reduced the intensity of pain, improved sleep and was well tolerated. Further long-term safety and efficacy studies are indicated.”

Cannabis Pharmacy author Michael Backes writes that this study is particularly significant because the best results were observed at the lowest dose, highlighting “the unexpected medical effectiveness of cannabis dosages that are far below those commonly consumed within the medical community.”

Finding the right product and dose for your neuropathic pain

Backes suggests that a variety of cannabis products, from topicals to oils to flower, may help a variety of neuropathy-related symptoms.

Natural Care nurse practitioner Lynn Haslam says she typically starts neuropathic pain patients on a low nighttime dose of a balanced CBD to THC oil. “We really want the pain managed so they can sleep,” she says. “Neuropathic pain typically gets worse at night, electric shock-like. We may not be able to diminish all of these sensations, but if we can restore sleep, which will help decrease pain during the day, that may be a reasonable goal.”

Setting realistic goals and weighing risks versus benefits is important when working with any medication, adds Haslam. “First-line therapy for neuropathic pain can be nortriptyline or amitriptyline,” she says, “and these medications can cause issues with older adults. This is the same with the other medications commonly used – gabapentin or pregabalin. I think cannabis is usually worth trying.”

In the absence of research that conclusively says which dose and product will work for which type of patient, Natural Care takes a conservative, personalized approach.

“Of course, we follow the latest cannabis research with great interest,” says Newell. “The more studies the better. But on a day to day basis, we weigh potential risks and benefits in a highly individual way – what medications is the patient taking? Are they at risk for drug interactions or falls? Have they had good or bad experiences with cannabis already? What is the nature of their pain, and have they tried other treatments? Then we start at the lowest dose possible and see if it helps. For many of our neuropathic pain patients, that’s enough.”

Can an Oromucosal Spray of THC-CBD Reduce Chronic Neuropathic Pain?

Noncancer-related chronic neuropathic pain may be effectively reduced by treatment with a mixture of tetrahydrocannabinol (THC) and cannabidiol (CBD), but additional large clinical trials are needed to assess the true impact of the medication on this condition. These results were published in the journal Pain Medicine.

Nabiximols (Sativex® oromucosal spray, GW Pharmaceuticals/Jazz Pharmaceuticals) — a complex, botanical mixture of THC and CBD with other cannabinoid and noncannabinoid components — is approved in certain countries, not including the United States, as an add-on therapy for people with chronic neuropathic pain who have inadequate relief from opioids and other analgesics. While numerous systematic reviews and meta-analyses have evaluated both cannabis and cannabinoid-related products (including nabiximols) for chronic pain management, no published reports to date have specifically reviewed the role of nabiximols in chronic neuropathic pain.

Researchers therefore conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) of nabiximols and placebo treatments for chronic, noncancer neuropathic pain. Inclusion was restricted to double-blind RCTs.

The meta-analysis included 9 RCTs with a total of 1289 patients (633 treated with nabiximols and 656 who received placebo). Included patients had neuropathic pain of various etiologies, including multiple sclerosis or other neurological defects, spinal cord injury, brachial plexus avulsion, postherpetic neuralgia, peripheral neuropathy, radiculopathy, complex regional pain syndrome type II, postherpetic neuralgia, peripheral neuropathy, focal nerve lesion, and diabetes. Seven studies had parallel group designs and 2 were crossover studies.

Mean study duration was 7.2 weeks. The maximum allowed dosage of nabiximols was 12 to 48 sprays per day (mean dosage, 8-10.9 sprays per day). Patients were permitted to continue treatment with any underlying analgesic medication, with treatment and control groups generally well-matched for concurrent medication. Baseline pain severity was moderate in all studies.

Results of a meta-regression showed no correlation of efficacy with either treatment duration (correlation coefficient [r]=−0.04; P =.386; R 2 =10.9%) or maximum daily dosage (r=0.01; P =.659; R 2 =10.9%).

A pooled endpoint for change in pain scores was significantly in favor of nabiximols over placebo; effect size estimate was −0.40 (95% CI, −0.59 to −0.21) in a fixed effect model and −0.44 (95% CI, −0.70 to −0.19) in a random effects model. Statistical heterogeneity was deemed not important (I 2 =39%).

Nabiximols were associated with a small but significant treatment effect across studies. Standardized mean difference was −0.21 (95% CI, −0.32 to-−0.10) in the fixed effect model and −0.26 (95% CI, −0.42 to −0.10) in the random effects model, with moderate statistical heterogeneity (I 2 =43%).

Sensitivity analysis of effect size estimates for change in pain scores favored nabiximols over placebo for indications of MS or other underlying condition, central or peripheral chronic neuropathic pain, treatment duration ≤6 weeks or >6 weeks, and maximum allowed daily dosage of nabiximols.

Study limitations include the short treatment period in some studies and population heterogeneity in terms of the underlying chronic pain condition.

The results of this analysis suggest that therapy with nabiximols oromucosal spray for chronic noncancer neuropathic pain refractory to usual treatments may be associated with a treatment effect, although not yet statistically significant.

“The emergent message is that individualized RCTs should generally be larger and adequately powered to show a statistically significant effect,” they concluded. “At present, additional larger RCTs specifically designed to assess the effect of nabiximols in neuropathic pain are required” in order to enable more definitive conclusions to be reached.

Disclosure: Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.

Using Cannabidiol to Treat Diabetic Peripheral Neuropathy of the Feet

Subjects will be enrolled in the study for a maximum of 43 days, including an optional 14-day screening period, 28 days of active product administration, and followed by a post-treatment follow-up within 1 day.

The primary objective of this study is:

  • To evaluate the safety of PG-DN-20WS for the treatment of painful DPN of the feet compared to a placebo control, including emergence of suicidal thoughts.

The secondary objectives of this study are:

  • To evaluate the impact of PG-DN-20WS on subject’s neuropathic pain, anxiety, and sleep quality compared to a placebo control.
  • To evaluate the impact of PG-DN-20WS on the subject’s impression of their response to the treatment compared to a placebo control.

Layout table for study information

Study Type : Interventional (Clinical Trial)
Estimated Enrollment : 50 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Intervention Model Description: There are 2 groups in this trial: interventional group (active drug) and control group (placebo).
Masking: Double (Participant, Investigator)
Masking Description: Subjects will be randomized at a 1:1 ratio.
Primary Purpose: Treatment
Official Title: A Randomized, Double-Blind, Placebo-Controlled Trial Using Cannabidiol for the Treatment of Painful Diabetic Peripheral Neuropathy of the Feet
Actual Study Start Date : December 10, 2020
Estimated Primary Completion Date : March 1, 2021
Estimated Study Completion Date : April 1, 2021
    Incidence of treatment-related adverse events as assessed by CTCAE v4.0 [ Time Frame: Four Weeks ]
    Pain as assessed by Numerical Pain Rating Scale (NPRS) [ Time Frame: Four Weeks ]

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

Layout table for eligibility information

Ages Eligible for Study: 21 Years and older (Adult, Older Adult)
Sexes Eligible for Study: All
Accepts Healthy Volunteers: No
  1. Subject is at least 21 years of age;
  2. Subject has a diagnosis of diabetic neuropathic pain of the feet determined by the subject’s primary care physician or related health care provider.
  3. Subject has a mean pain scale score of ≥ 5 recorded in the 7 days prior to randomization.
  4. If female, the subject is postmenopausal (> 1 year), surgically sterile (> 3 months), had a hysterectomy, or is currently using 2 effective forms of birth control.
  5. Subject has not taken marijuana (cannabis) in any form, chemicals or extracts or foods or beverages or topical creams, lotions, gels, patches containing marijuana (cannabinoids, or and cannabis derivatives) including synthetic marijuana and/or CBD for at least 14 days prior to this study, and agrees to not take marijuana (cannabis) in any form, chemicals or extracts or foods or beverages or topical creams, lotions, gels, patches containing marijuana (cannabinoids, or and cannabis derivatives) including synthetic marijuana and/or CBD while participating in this study.
  6. If subject is currently taking gabapentin, pregabalin, or duloxetine, subject must be willing to and completes a 7-day washout of these medications prior to randomization.
  7. Subject has not taken any NSAIDs and/or acetaminophen for at least 2 days prior to randomization.
  8. Subject is willing to provide his/her written informed consent to participate in the study as stated in the informed consent document.
  9. Subject is willing to use an electronic diary to enter trial information for 29 days.
  1. Subject is pregnant or lactating;
  2. Subject has an allergy to cannabis, the Cannabaceae plant family (e.g., hemp, hops), palmitoylethanolamide, or terpenes;
  3. Subject has a known allergy to active or inert ingredients of the investigational product;
  4. Subject is taking a concomitant medication or treatment that would complicate use or interpretation of the study drug’s effects (examples include: Cannabis or any cannabinoid products; Any drug or herbal product that influences the endocannabinoid system (ECS));
  5. Subject is taking marijuana (cannabis) in any form, chemicals or extracts or foods or beverages or topical creams, lotions, gels, patches containing marijuana (cannabinoids, or and cannabis derivatives) including synthetic marijuana and/or CBD for at least 14 days prior to this study, and does not promise that they will not take marijuana (cannabis) in any form, chemicals or extracts or foods or beverages or topical creams, lotions, gels, patches containing marijuana (cannabinoids, or and cannabis derivatives) including synthetic marijuana and/or CBD while participating in this study;
  6. Subject currently resides in the state of Nebraska, Idaho, Iowa, or South Dakota.
  7. Subject is currently being treated with antibiotics for sinus, throat, or lung infections;
  8. Subject has shortness of breath associated with allergies;
  9. Subject has uncontrolled asthma;
  10. Subject has a fever and/or productive cough;
  11. Subject has unstable angina, uncontrolled hypertension;
  12. Subject currently or has a history of congestive heart failure;
  13. Subject has any other unstable medical condition;
  14. Subject has a personal or family history of schizophrenia;
  15. Subject has a personal history or currently has suicidal ideation or attempted suicide;
  16. Subject has a major neurological disorder, such as dementia, Parkinson’s disease, cognitive impairment, epilepsy, history of traumatic brain injury/head injury, and seizures.
  17. Subject has taken pharmaceutical pain medicine of any kind, or has taken a NSAID and/or acetaminophen, within 2 days of randomization.
  18. Subject has taken gabapentin, pregabalin, or duloxetine within 7 days prior to randomization or is unwilling to stop these medications.
  19. Subject has an allergy to, or has an intolerance to, NSAIDs or acetaminophen.
  20. Subject is currently taking any form of opioids.
  21. Subject has a history of substance or alcohol abuse.
  22. Subject has clinically significant illness, including cardiovascular disorders.
  23. Subject has any condition in which the investigator believes will confound the data of the study or could put the subject at risk of harm.
  24. Subject does not have access to a smart phone or does not know how to use a smart phone application.

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.