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NEJM Debate on Medical Marijuana for Chronic Pain

Oct 18, 2018 12:01 pm

This week’s NEJM features a case discussion and debate over whether medical marijuana should be used to treat chronic pain. The debate focuses on a 31-year-old woman with long-standing complex regional pain syndrome in her leg and foot. CRPS followed a sports related hairline fracture in the right fibula. Her pain has been intractable since.

She has previously been insufficiently treated with several opioids, regional and sympathetic nerve blocks, transcutaneous nerve stimulation, lidocaine, behavior modification, acupuncture, and alendronate infusions.

Currently she is taking gabapentin 600 mg orally three times a day, and oxycodone, of 20 mg per day. She is asking about medical marijuana for her chronic pain.

Option 1: Prescribe Medical Marijuana

Dr. Benjamin Caplan, from the CED Foundation andCED Clinic, favors cannibis, making the following points:

  • Cannibis has proven efficacy in the treatment plan for chronic pain and allodynia.
  • It may be a replacement for opioids.
  • Cannabis added to her regimen could alleviate emotional distress of her non response and add to her pain relief.
  • Cannabis works through cannabinoid-receptor and non–cannabinoid-receptor mechanisms, to antiinflammatory and neuroprotective effects that may alleviate chronic pain.
  • A recent study of refractory pain, cannabis showed efficacy in patients for whom traditional treatment options had failed.
  • There are few clinical trials focused on pain control in humans that quantify adverse effects of medical marijuana.
  • This patient is frustrted with the inefficacy, side effects, and addictive nature of opioids.
  • Cannabis or oral formulations of cannabinoids should be safe for this patient
  • From cannibis she may expect moderate analgesia, reduced allodynia, muscle relaxation, a reduced stress response to her disability, and an empowering level of control over mood in coping with her illness.

Option 2: Discourage the Use of Medical Marijuana

Edgar Ross, from the Brigham and Women’s Hospital, and Harvard Medical School, would discourage cannibis use, making the following points: 

  • Support for and legalization most of the 50 states, is based largely on anecdotal information.
  • Medical marijuana contains many compounds, of which approximately 60 are cannabinoids. The two principal cannabinoid receptors are receptor 1 (CB1) and receptor 2 (CB2).
  • Data on the efficacy of medical marijuana are very limited with regard to teh effectiveness and side effects.
  • Studies suggest that the analgesic potency of cannabinoids is roughly similar to that of codeine.
  • Side effects of cannabinoids include sedation, dizziness, dry mouth, dysphoria, appetite stimulation, and short-term memory loss.
  • Long-term exposure to cannabis has also been associated with a risk of psychotic disorders, including latent schizophrenia and cannabis-associated psychosis.
  • Delivery of cannabinoids are problematic. Oral cannabidiol bioavailability varies. Smoking marijuana has better bioavailability than oral formulations, but the smoke itself is a risk factor for chronic obstructive pulmonary disease.
  • This patient has not yet been treated with the standard of care that would include a multidisciplinary treatment programs and a team approach, specializing in psychological therapies, rehabilitation, and pain specialty care.
  • There are also other proven therapies that are known to be effective for neuropathic pain, which include antiepileptic drugs (only gabapentin has been tried), antidepressants, and even spinal cord stimulation.

The online poll, with over 1200 responses shows that >70% of the audience favors the use of cannabinoid therapy.


The author has no conflicts of interest to disclose related to this subject

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