The legalization of marijuana (cannabis) for medical use in 29 states and the District of Columbia (as of the writing of this article) has fueled a growing acceptance of marijuana as a treatment option for a number of conditions. Despite criticism of the programs (whether for prescribed medical conditions or recreational), there is real science behind the use of cannabinoids for therapeutic effects by binding to specific receptors on the surface of cells. The commercial availability of medical cannabis has moved patient usage quickly, and many unanswered questions remain as to how to best utilize these medical marijuana product offerings.
Medical cannabis may be identical in form to recreational marijuana because both are derived from the Cannabis plant (agricultural base). Products from the plant (and not just from chemicals or “synthetic”) cannabis consist of two main components, THC (tetrahydrocannabinol) and CBD (cannabidiol) and secondary components present in smaller amounts (terpenes) that may also provide unique benefits. THC has the psychoactive properties that make people feel high, but many patients find that uncomfortable. CBD, on the other hand, offers some of the benefits without the buzz. Hemp, which is legal, generally has negligible THC levels.
THC and CBD, the main components of medical cannabis bind specifically to receptors on the surface of nerve cells (neurons) in much the same way as many active medicines
This is the introduction (Part 1) for a 3-Part series on “Medical Cannabis for Neuropathic Pain”. In Part 1 (below) I will describe the use of medical cannabis today by neuropathic pain patients. The upcoming Part 2 will discuss the science on how and why cannabis works at the cellular receptor level and the clinical research that has been done to date in patients with neuropathic pain.
Also in Part 2 of this series, we will discuss the mechanism of action for medical cannabis, which has been well described over the last 3 decades. As is shown in the graphic to the left, THC and CBD, the main components of medical cannabis bind specifically to receptors on the surface of nerve cells (neurons) in much the same way as many active medicines. Animal studies show that the effects (both positive and negative) from medical cannabis are predictable and undeniable.
The concluding Part 3 will discuss the wide range of cannabis products containing different amounts of THC and CBD (diagram below) including formulations, strains and “ratios”. The medical community is just starting to learn how to customize the products for particular patients symptoms and needs. The diagram below outlines the different conditions and the predominant component of medical cannabis that may be recommended for them by their physician.
The medical cannabis preparations allowed for sale in many states adhere to general pharmaceutical principles and packaging. Examples of cannabis products (tinctures and oils) and representative packaging in NY State are in Figure 4, below.
So, let’s get started…
Medical Cannabis Use for Neuropathic Pain – Part 1
The Situation Today
Registered physicians in at least half the states in the USA approve medical cannabis for sale to qualified registered patients. In a May 2013 survey on the Medical use of Marijuana, published in the New England Journal of Medicine, 76% of physicians surveyed were in favor of the use of marijuana for medicinal purposes. Despite this, marijuana is still considered on a national level (by the DEA) to be under schedule 1 rules and regulations, meaning it is a strictly controlled substance subject to the same federal felony rules for misuse as heroin.
In this interesting nation vs. state situation, individual states willing to permit the cultivation and sale of medical cannabis are able to choose their approved conditions, allowable formulations, and timing of refills. Because medical cannabis is not an FDA approved product, it is not technically “prescribed”, therefore physicians are given little direction by the states on which products and ratios might be appropriate for their patients.
Virtually all jurisdictions that permit cannabis patient usage “allow” treatment for neuropathic pain or neuropathy as a qualifying condition, all but 3 states providing for use under the catchphrases “including but not limited to” and “chronic pain …not relieved by…
Only three states specifically list neuropathy as a qualifying condition. In those states, neuropathic pain is one of the most common uses for medical cannabis. Illinois provides a very comprehensive list of many types of neuropathy in what they consider allowable conditions for medical cannabis. New Mexico permits use of medical cannabis for “painful peripheral neuropathy”, and New York permits use of medical cannabis for “neuropathy pain”.
In the state of New York, where regulations allow for more complete data collection regarding patients using medical cannabis, Columbia Care Corp. has the following breakdown of their patients using medical cannabis. The following graphic illustrates the percentage of their customers who have the different state approved conditions, and the demographic breakdown of the patients with those conditions.
In August 2016 Columbia Care sent out an email asking medical cannabis registered NY patients to participate in an on-line survey. The top 5 reported types of pain in respondents were neuropathic (63%), joint/muscular (56%) headache (23%), abdominal (19%) and other (15%).
The survey had drop downs for the state approved qualifying conditions, so responders with Neuropathy Pain could be analyzed as a group. There were 235 responders with Neuropathy Pain as their qualifying condition.
The top 5 reported symptom types in patients with Neuropathy Pain were Pain; neuropathic chronic or generalized (80%), muscle spasticity (40%) depression/anxiety (40%), sleeplessness (30%) and joint inflammation (30%).
As will be discussed in part 3 of this series, patients with neuropathic pain are often recommended a 1:1 or CBD predominant medical cannabis formulation. Survey respondents indicated (Figure 4) that the majority of patients are on a High THC: Low CBD mixture, whereas 34% are on a 1:1 hybrid mixture, and the fewest are on a Low THC: High CBD ratio.
THC makes people feel high, CBD offers some of the benefits without the high.
The product that many patients were currently using was not what was originally recommended by their doctor in over 40% of the cases. (Figure 7). Although on-line surveys are not scientific, it isn’t hard to think many patients may have changed their original physician recommended THC : CBD ratio over time to balance relief with adverse effects.
The most commonly reported unwanted effects from medical cannabis in the surveyed patients are shown in Figure 5: increased appetite (32%) and sedation (25%). The complete results from this question in the survey are in Figure 8. The survey asked respondents about most of the common complaints that people have on cannabis. The “other” category did not have any one common complaint that was truly unique from the other choices.
Most importantly, Figure 9 shows that the majority (77%) of patients felt they were receiving at least some relief of their Neuropathy pain symptoms with medical cannabis.
Given the newness of the medical cannabis programs in most states, and the ever-evolving product assortments available, physicians and patients are still trying to understand the right product for them. Clinicians need to become familiar with both potential risks and benefits of medical cannabis.
Clearly there are a lot of additional studies to be done to help provide data to recommending physician and the pharmacists about the best choice for individual patients.
I hope you find these articles informative and encourage you to contact the Neuropathy Journal, and/or myself, with any questions you may have by clicking here or by commenting below.
In Part 2 of this series on “Medical Cannabis for Neuropathic Pain”, we discuss the active ingredients of medical cannabis. Animal studies show that the effects (both positive and negative) from medical cannabis are predictable and undeniable. You can read the second article of this series “Medical Cannabis for Neuropathic Pain – Part 2 of 3” by clicking here.
In Part 3 of this series on “Medical Cannabis for Neuropathic Pain”, we will discuss which formulation of THC or CBD is best for patients with certain conditions and symptoms, including treating neuropathic pain. You can read the final article of this series “Medical Cannabis for Neuropathic Pain – Part 3 of 3” by clicking here.