Topical & Transdermal Cannabinoid Therapy in Treatment of Rheumatoid Arthritis
By Gaurav Dubey (M.S. Biotechnology) STAFF
What is Rheumatoid Arthritis?
Rheumatoid Arthritis (RA) is an autoimmune and progressive inflammatory disease that affects approximately 1% of the world’s adult population and, if left untreated, may lead to joint destruction and disability (Kahlenberg & Fox, 2011) (Heidari, 2011). RA is characterized by inflammation of synovial joints and, in the absence of treatment, inflammation will lead to articular damages and bone erosion generally within the first two years of disease onset (Graudal, 2004). In regards to the treatment of RA associated pain, opioid medications have been a mainstay for moderate to severe pain.
However, the recent opioid epidemic has cast a heavy shadow on this class of analgesics, especially when considering their high abuse potential, side effect profile, inhibition of wound healing and potential for fatal overdose (Maida & Corban, 2017). Medical cannabis has begun to present itself as a “novel analgesic strategy” that is rapidly replacing the need for these more dangerous opioid drugs in the treatment of pain (Maida & Corban, 2017). Furthermore, the anti-inflammatory effects of CBD (cannabidiol), a non-psychoactive constituent of the Cannabis Sativa plant, seems to mitigate pain related behaviors and inflammation in rat models of arthritis while presenting minimal, if any side effects (Hammell et al., 2015).
Bioavailability of Cannabis and CBD
Due to the poor bioavailability of oral CBD, the efficacy of topical and transdermal applications of CBD has become of great interest to researchers and patients alike. This review will examine the current, albeit limited literature revolving around the treatment of RA and RA associated pain by topical and transdermal applications of cannabinoids such as CBD.
The rapid increase in the popularity of medical cannabis as an alternative to more traditional allopathic medications is a phenomenon being observed across a broad clinical spectrum, ranging from neuropathic pain to psychiatric applications such as PTSD. While medical cannabis further finds its way into the mainstream, its versatile pharmacology has allowed for a diversity of products that extend far beyond simply smoking the flower.
While modern day extracts known as “dabs” may be more reminiscent of hashish, newer applications of cannabis, such as topical and transdermal cannabinoid extracts offer, revolutionary therapeutic potential for various conditions. The topical application of CBD gel seems to offer both pain relief and attenuation of inflammation associated with Rheumatoid Arthritis (Hammell et al., 2015). In fact, Hammell and colleagues’ study demonstrated that transdermal CBD gel significantly “reduced joint swelling, limb posture scores as a rating of spontaneous pain, immune cell infiltration and thickening of the synovial membrane in a dose-dependent manner”, indicating the potential value of this treatment modality in treating both RA symptomatic pain and potentially reversing inflammatory damage caused by this disease (2015).
Transdermals, Topicals and Concentrates
While the topical and transdermal medical cannabis products being offered today are fairly new to the market, the topical application of cannabis extracts to wounds dates back thousands of years (Maida & Corban, 2017). In their newly published 2017 study, Maida & Corban demonstrated that topical application of cannabis extract demonstrated “clinically significant analgesia that was associated with reduced opioid utilization” in all three cases of wound pain in their study. The novelty of such topical cannabinoid treatment includes a lack of systemic side effects, is noninvasive in nature, can be self-administered and displays rapid onset of analgesia (Maida & Corban, 2017).
The incredibly high safety profile and therapeutic index of medical cannabis, especially when contrasted with opioid analgesics, warrants further research into topical cannabinoid treatment for “patients suffering from wounds of all classes” (Maida & Corban, 2017).
Topical preparations for pain and inflammation relief offer a variety of benefits over more traditional oral medications, as noted earlier. The current mainstay treatments for RA include a class of medications called “DMARDs” or “Disease Modifying Antirheumatic Drugs” (Heidari, 2011). One of the most popular medications for RA in this class of drugs is Methotrexate and is often used in combination therapy with other DMARDs in the treatment of this condition (Heidari, 2011). DMARDs show high efficacy and success in treating RA when started as early in the disease progression as possible, thus, patients with suspected RA should seek medical help promptly (Wilsdon & Hill, 2017).
However, this class of medication is often used in combination and carries the risk of “serious adverse effects” that necessitates frequent patient monitoring (Wilsdon & Hill, 2017). As such, the use of topical cannabinoid drugs to treat both the progression and symptoms of RA may decrease the magnitude and frequency of more invasive pharmacological interventions. This is especially true if the patient is able to find relief from chronic pain using a topical cannabinoid gel or transdermal patch as chronic pain severely affects quality of life in patients who suffer from it.
Cannabis and the Opioid Epidemic
The opioid epidemic has made it resoundingly clear that newer, safer and more novel non-opioid analgesic therapies better suited for long term use is a dire necessity. Medical cannabis as a whole has dramatically reduced opioid prescription rates and overdoses/fatalities in states that have effectively implemented a medical cannabis program (Bradford & Bradford, 2016). Further research into topical and transdermal cannabinoids as a safe alternative and/or adjunctive treatment of a condition as potentially damaging and painful as RA could be a promising avenue of investigation both for patients and healthcare providers alike.
Cannabis is quickly finding itself in a versatile position in the medical field and clinical arena. Unlike most drugs created by the pharmaceutical industry, the medical cannabis movement has always been patient driven and continues to be fueled by each individual member, whether patient, advocate or both. The rapidly gaining popularity of topical and transdermal cannabis treatment for RA related pain and inflammation has already warranted early animal studies, however, requires far more resources for further research and investigation. Hammel’s 2015 study demonstrating the efficacy of topical CBD gel in rodents with RA associated inflammation and pain is a great start (Hammell et al., 2015).
However, patients are successfully using topical and transdermal cannabis every day to treat these very same conditions. The incredibly high therapeutic index of cannabis along with its minimal side effect profile and virtually zero chance of fatal overdose has allowed for a phenomenon where myriads of anecdotal patient driven “trial and error” reports have collectively begun to paint a more nuanced portrait of all the potential therapeutic applications medical cannabis may have.
For now, the data certainly suggests there is promise in the treatment of RA with topical and transdermal cannabinoids. Hopefully, moving ahead, we can further establish the pharmacological mechanisms that underlie the benefits topically or transdermally applied cannabinoids have on the disease and how to best approach utilizing this unique treatment strategy to attack it.