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11 Articles in Volume 10, Issue #7
Selecting an Antidepressant for Pain Patients
Use of Opioids in Pain Patients with Psychiatric Disorders
Osteopathic Medicine Approach to Pain Management
Cannabis as Medicine
Pain Management in Patients with Pyoderma Gangrenosum
Occipito-Atlanto (C0-C1) Joints as a Source of Spinal Pain
Treat the Pain First—Worry about Psyche Problems Later
Traditional Chinese Medicine for Fibromyalgia
TMJ Condylar Pain From Parapharyngeal Space Tumor
Contraindications for Use of Therapeutic Laser
Platelet-Rich Plasma Prolotherapy for Low Back Pain Caused by Sacroiliac Joint Laxity

Cannabis as Medicine

Some observations about a controversial treatment.

Editor’s note: Be clearly advised that Practical Pain Management neither endorses, supports, or condemns the use of cannabis in pain treatment. We have chosen to publish this article from among others we have received on this subject because it presents what appears to be factual information from Montana, a state that fundamentally has sanctioned its use.

Published in 2010 by K. Allan Ward


In this article, we will use the term cannabis, since marijuana is a term which is considered racist and derogatory to many international readers. Cannabis has achieved semi-legal status in the United States for use as a medicine in 14 states,1 although its status by federal classification remains Schedule I under the Controlled Substances Act:

A) A drug or other substance that has a high potential for abuse.
B) A drug or other substance that has no currently accepted medical use in treatment in the United States.
C) There is a lack of accepted safety for use of the drug or other substance under medical supervision.”2

Therefore, prescribing cannabis is impossible under present DEA regulations and knowingly prescribing controlled substances to a person who is using cannabis—regardless of whether for medicinal or discretionary purposes—will potentially violate DEA licensure for the provider. Two synthetic prescription medications currently exist in the U.S. that can be prescribed. This conflict in its legal status between state and federal regulation remains a gray area and will be discussed in this article. The author lives in Montana, which legalized the medical use of cannabis in 2004. We will discuss how its use in pain medicine might be approached without forfeiting DEA licensure.

The Montana Experience

Presently, there are more than 14,000 registrants in Montana with more than 11,000 giving ‘chronic pain’ or ‘chronic pain and muscle spasms’ as the reason for registration.3 There are more than 2,500 “medical caregivers” who are registered to grow and provide cannabis to the patients. Montana law also allows for a registered caregiver to grow and provide cannabis to the registered user.

At the time of publication, no providers in Montana have had to either forfeit their DEA license or been subjected to state licensing board discipline for prescribing controlled substances with cannabis use. One provider has been censured for inappropriately providing registration in a series of clinics held on weekends with hundreds of registrations in each clinic. One provider in Montana has provided more than 3,000 registrants with certification to use medical cannabis. In most cases, after registration is obtained, the “patient” has no formal followup with the provider until the next year for renewal. Cities and counties in Montana have varied widely in their approach to the issue of medical cannabis. Some have local laws banning its use. Others have formal regulation of the provider storefronts. An informal survey by local journalists has not revealed a significant difference in criminal activity in the municipalities with a high tolerance for use. The overarching concern has been the bogus acquisition and use of cannabis by young persons, some of who are still in high school.

Online Survey of Cannabis Users

The author performed an open-ended online survey of cannabis users in Montana. The survey was advertised by giving an interview which was published in the five largest newspapers in Montana and spread to the internet news sources for medical cannabis and cannabis reform. There were 360 participants, with 292 of them being Montana medical cannabis registrants. Of the 292 responding as Montana registrants, only 13% were between the age of 21 and 30 years while actual MT registration statistics indicate that more than 25% of the registrants are in that age range. Because of the methods used, and comparison to the known registrants from Montana state sources, the survey may not be representative of the actual registrant population. 79% of the respondents have a caregiver but 48% also grow their own cannabis.

Background of Cannabinoids

A synthetic form of the main psychoactive ingredient of cannabis—tetrahydrocan-nabinol-delta-9 (THC)—has been available by prescription in the USA since 1986 (dronabinol, marketed as Marinol®) and was downgraded from Schedule II to Schedule III in 19994 when it was noted that it has little street value because its cost exceeds the cannabis available.5It is listed for use in nausea and vomiting associated with cancer chemotherapy and appetite improvement for patients with AIDS. An additional synthetic cannabinoid, race-mic-nabilone (marketed in the USA as Cesamet®), has approval for chemotherapy-related symptoms. Some providers have used both medications for chronic pain. In Canada and Europe, a cannabis-based medical extract is approved for use as an oromucosal (mouth) spray (Sativex®). This product is entirely derived from the cannabis plant itself—with specially grown cannabis plants—and an extensive quality control process involved in production. A book was written about the development of this product,6 which has entered Phase 3 drug testing in the USA.

Table 1. Survey Results of 292 Medical Cannabis Registrants in Montana
Demographics Treatment Outcomes Other reported issues
Female 38% Improved pain relief 88% Required medical treatment for
drug overdose
Male 67% Reduced anxiety 70%    
Currently employed 55% Reduced muscle spasms 61%    
21 to 30 year-old 13% Decrease in medication use 74% Treated for emotional difficulties
by a counselor, psychologist or psychiatrist
31 to 40 year-old 24% Adverse side-effects    
41 to 50 year-old 22% Decreased short-term memory 38%    
51 to 60 year-old 30% Poor ability to concentrate 23% Charged with driving under the influence of alcohol 10%
Cannabis ingestion16% Delays in reaction time 10%    
Smoking 85% Anxiety 8% Consume tobacco 41%
Eaten in food 60% Onset of cannabis use Take prescription medications
(of these, 56% take controlled substances)
Vaporizer 42% Before age 18 50%   10%
Tinctures 32% Between 18 and 25 30%    
Cannabis Tea 17% Frequency of use    
Preferred method of use 3 or more daily with a reported cost of $200-$400 per ounce 53% Experience extreme intoxication when using cannabis with prescription medications or alcohol 14%
Smoking 54 Drug experimentation among respondents    
Eaten in food 17% Mushrooms 88%    
Vaporizer 22% Cocaine 63% Eendered unable to perform some activities when using cannabis 15%
Tinctures 6% LSD 57%    
Cannabis Tea 1% Amphetamines 39%    

A synthetic cannabinoid receptor inverse agonist—rimonabant (Acomplia®)—was approved in Europe for use in obesity, but with reports of “serious psychiatric disorders” associated with its use, was withdrawn from the market in 2009.7 It was never marketed in the United States.

Cannabinoid receptors were identified in 1988.8 There are two general receptor types, CB1 (generally in the CNS) and CB2 (generally in the immune system).9 These effects are widespread, and act upon the gastrointestinal, cardiovascular and skeletal system.10 The major endogenous cannabinoids in humans are anandamide and 2-arachadonoyl glycerol (2-AG).11 Cannabis has a widespread variation on its constituents, and has been cultivated for thousands of years. The desired content for discretionary use is the psychoactive substance, THC, which is primarily a CB1 agonist. Another major constituent is cannabidiol (CBD), which has little or no psychoactive effects.6 Almost all of the cannabinoids have anti-inflammatory effects.7 It is felt that the combination of active ingredients in cannabis exert an entourage effect5 which explains better results with cannabis than the single-agent CB1 agonists currently available in the United States.


Because of the prevailing federal policy which regulates controlled-substance prescribing and dispensing, we have been given a legal opinion by counsel that knowingly providing controlled substance prescriptions or dispensing intrathecal controlled-substances to cannabis users could result in a loss of licensure, although we are not aware of this actually occurring. We have a policy of including a paragraph in service agreements for intrathecal pumps and controlled-substance prescribing that states we will not prescribe controlled-substances for persons continuing to use cannabis. From a technical standpoint, it doesn’t appear that cannabis has significant drug interactions with opioids. Additive effects on motor control and mental status do occur. Studies regarding alcohol use with cannabis have shown significantly higher risks in operating motor vehicles.12

Concerns and Benefits of Cannabis

The safety profile of cannabis is well-established. The toxicity of the substance is extremely low; it is essentially impossible to consume a toxic amount of cannabis. The primary concern of medical and health organizations is that smoking anything is an unhealthy practice, so other routes of administration need to be employed if cannabis is to used for medical conditions.

Psychiatric side-effects can be severe in persons with pre-existing psychiatric conditions such as bipolar disorder and schizophrenia, especially when cannabis is used in adolescence, with cannabis use before age 15 resulting in a four-fold increase in psychosis by age 25.13-15 There are reports of cannabis-induced psychosis, although this may be an early appearance of psychosis which can improve with abstinence.16 It appears that cannabis use under the age of 20 may have negative effects on the maturing nervous system.

There are many small studies that have touted cannabis use for seizures, polyneuropathy, anxiety and chronic pain. Its use for symptom management in multiple sclerosis, including pain, spasticity and possibly fatigue, is established.17

Case Report 1. The patient was a 69- year-old female with widely metastatic breast cancer, seen in pain clinic for severe back pain, with radiation of pain into the left foot. MR imaging demonstrates a left paracentral disc protrusion at the lumbosacral junction. She has significant nausea with the use of oral opioids. She is given a transdermal fentanyl patch (0.025 mg per hour), which is tolerated somewhat better but still causes nausea. She has lost more than 40 lbs during and after the chemotherapy and describes anorexia. A fluoroscopically-guided caudal epidural steroid injection provided about 25% relief. She was started on Cesamet® (nabilone) 1 mg twice daily, which improved her nausea and also improved her appetite. The effects lasted for about 9 hours, so she began to take the medication at 1 mg three times daily. This provided good relief of her pain and nausea, with an improved appetite. She was pleased with the combination of the fentanyl and nabilone.

Case Report 2. The patient is a 74-year-old female with a history of a left thalamic stroke, with no residual weakness or functional deficits. She developed a severe hemidysesthesia after the stroke, affecting her right side, with facial involvement. She has been diagnosed with Alzheimer-type dementia as well. She has been tried on gabapentin, pregabalin, amitriptyline, nortriptyline, duloxetine and transdermal fentanyl, none of which have been helpful. She is being given Aricept® (donepezil) and Namenda® (memantine HCl) combination therapy. She is taking transdermal fentanyl (0.025 mg per hour, changed every 3 days). She has had some moderate relief with naproxen, but this was withdrawn when she had mild kidney failure. A friend shared some cannabis-containing cookies that gave her very good relief and allowed her to sleep for six hours. Her provider will not give her the permission to use medical cannabis with the fentanyl. Subsequently, she was given a prescription for Marinol® (dronabinol), 5 mg. Her first dose made her sleep for more than 18 hours. This was adjusted to the 2.5 mg dosage, which was less sedating, and gave fair pain relief. The patient noted that the cannabis-containing cookies were superior.

Case Report 3. I was asked to see this patient as a pain consult. The patient is a 52-year-old male, a disabled nurse with three previous spine surgeries. He has been prescribed 80mg of extended-release oxycodone 3 times daily, with 4mg of immediate-release hydromorphone every 4 hours for breakthrough pain, up to 5 times daily. Additionally, he is taking carisoprodol 350mg 5 times daily and diazepam 10mg 3 times daily. He has refused to obtain a primary-care provider for his medical needs, and refused to consider any change in the oral medications. Unbeknowst to the provider, and having failed to mention it in an initial interview, the patient had obtained a medical cannabis registration and was using cannabis regularly. A routine initial urine drug screen demonstrated a positive cannabis use. Upon being made aware of this, the patient stated that he had the right to use the cannabis since he had a registration. He was offered the alternative of dronabinol, but refused it. As a result, he sought another provider for his treatment.


Cannabis use in public policy remains controversial because of state and federal law contradictions. These issues involve both discretionary use and the legitimate medical use of cannabis, either as a botanical product or as a medical extract. The pain practitioner has a special concern, since it appears that cannabis has profound and unique effectiveness for some painful and disabling conditions.

In Montana, 299 persons died of prescription drug overdoses in 2009, with less than 25% of them having been prescribed the medications that were the cause of death.17 Although far less dangerous than any other controlled-substances (no deaths are known to have been caused by cannabis overdose), pain providers that prescribe controlled-substances and recommend cannabis use may—until a more uniform policy nationwide is established—be subject to loss of DEA licensure. We would hope that the future brings more clarity to these policies.

Notes and References

  • 1. As of early 2010, states with medical cannabis waivers include Alaska, California, Colorado, the District of Columbia (D.C.), Hawaii, Maine, Michigan, Montana, Nevada, New Jersey, New Mexico, Oregon, Rhode Island, Vermont and Washington. A pending referendum in California will pass overall legalization. Montana is considering a legislative overhaul of the current law because of concerns mentioned in this article. The reader should seek current information on this, as state laws are changing rapidly.
  • 2. www.justice.gov/dea/pubs/csa.html. Accessed 24 Aug 2010.
  • 3. www.usdoj.gov/dea/ongoing/marinol.html. Accessed 24 Aug 2010.
  • 4. Calhoun SR, Galloway GP, and Smith DE. Abuse potential of dronabinol (Marinol). Journal of Psychoactive Drugs. 1998. 30(2): 187-196.
  • 5. Guy GW, Whittle BA, and Robson PJ. (eds.) The Medicinal Uses of Cannabis and Cannabinoids. Pharmaceutical Press. 2004.
  • 6. Howlett AC. The cannabinoid receptors. Prosta-glandins Other Lipid Mediat. Aug 2002. 68-69: 619-31
  • 7. Graham ES, Ashton JC, and Glass M. Cannabinoid receptors: a brief history and “what’s hot.” Front Biosci. 2009. 14: 944-57
  • 8. Ibid. ref 5: pp 103-129.
  • 9. Lambert DM, and Fowler CJ. The endocannabinoid system: drug targets, lead compounds, and potential therapeutic applications. J Med Chem. 2005. 48(16): 5059-5087.
  • 10. Formukong, Evans, and Evans, “Analgesic and anti-inflammatory activity of constituents of Cannabis sativa L. Inflammation. 1988. 12(4): 361-371.
  • 11. www.dphhs.mt.gov/medicalmarijuana/mmpcurrentpatientcount.pdf. Accessed 24 Aug 2010.
  • 12. Ibid. ref 5: pp 329-366.
  • 13. Van Os J, Bak M, Hanssen M, Bijl RV, de Graaf R, and Verdoux H. Cannabis use and psychosis: A longitudinal population-based study. American Journal of Epidemiology. 2002. 156: 319-327.
  • 14. Arseneault L, Cannon M, Poulton R, Murray R, Caspi A, and Moffit TE. Cannabis use in adolescence and risk for adult psychosis: longitudinal prospective study. British Medical Journal. 2002. 325: 1212-1213.
  • 15. Henquet C et al. Prospective cohort study of cannabis use, predisposition for psychosis and psychotic symptoms in young people. British Medical Journal. 330, 11-14.
  • 16. Arendt M et al. Cannabis-induced psychosis and subsequent schizophrenia-spectrum disorders: follow-up study of 535 incident cases. British Journal of Psychiatry. 2005. 187: 510 - 515.
  • 17. Unpublished data from the MT Department of Criminal Investigation, courtesy of Mr. Mark Long, department chief.
Last updated on: February 21, 2019
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