Clinical Assistant Professor, Department of Family Medicine, University of Wisconsin; Clinical Assistant Professor of Medicine, Arizona Center for Integrative Medicine, University of Arizona, Tucson
Dr. Kiefer reports no financial relationships relevant to this field of study.
- Topical cannabis, providing both tetrahydrocannabinol and cannabidiol, had analgesic effects for two of three patients with a painful dermatological condition.
SYNOPSIS: For three people with continued pain despite conventional treatment for pyoderma gangrenosum, topical cannabis led to statistically significant pain relief for two of them.
SOURCE: Maida V, Corban J. Topical medical cannabis: A new treatment for wound pain — three cases of pyoderma gangrenosum. J Pain Symptom Manage 2017;54:732-736.
It’s not uncommon for methodologically sound clinical trials to trail slightly behind consumer dietary supplement use. One could argue that such is the case with cannabidiol (CBD) oil. CBD is one of the groups of physiologically active compounds extracted from hemp (Cannabis sativa), the other being tetrahydrocannabinol (THC). CBD is touted as an effective treatment for pain and for numerous other health conditions, without the psychotropic effects of THC.1,2,3 There is some interesting evidence surfacing for the anti-inflammatory effects of an interplay between CBD and THC, which Maida and Corban reviewed, pointing to effects on the human endocannabinoid system. It is this mechanism of action that led the authors to use topical cannabis for the difficult-to-treat skin condition pyoderma gangrenosum (PG).
In the article reviewed here, three people with PG confirmed by wound biopsies were treated with topical medical cannabis. The preparations used were created by infusing hemp (Cannabis sativa) in sunflower oil. One brand name was Argyle, with a THC content of 5 mg/mL and CBD content 6 mg/mL; (manufacturer Tweed [Canada]). Another was Bedrolite, with a THC content of 7 mg/mL and CBD content 9 mg/mL (manufacturer Bedrocan Inc). Characteristics of the three subjects, their initial medical treatment, and specific topical cannabis treatments are detailed in Table 1.
Patients reported analgesia within three to five minutes of applying the topical treatment. The researchers followed their pain scores on a scale of 0-10, both pre- and post-treatment, for a varying number of weeks as per Table 2. Of note, the mean daily opioid use decreased for the two patients (1 and 2) who were treated with opioid medications. For patient 1, the morphine equivalents decreased to 0.24 mg post-treatment from 26.0 mg pre-treatment. For patient 2, the morphine equivalents decreased to 12.5 mg post-treatment from 27.3 mg pre-treatment.
Yes, this is only a case series on three people with a painful skin condition, but the analgesic effects are impressive, both with pain scores and decreases in the use of opioid medications in two of the patients studied (interestingly, those who had higher baseline pain and were taking opioids for that pain). Is it sufficient for clinicians to incorporate this treatment into their clinical practices? By no means, not the least reason of which is because of state and federal laws governing the use of medical marijuana (cannabis). In addition, the results of this study are complicated by the fact that the researchers used a medical cannabis extract, including both phytochemical classes (CBD, THC), complicating the teasing out of clinical response to CBD or THC; we can only say that both groups of compounds together led to the improvements in pain seen. That said, with CBD oil appearing more and more in the marketplace, and on patients’ dietary supplement lists, perhaps this study is a first step toward providing clinicians information about how to counsel patients should they express interest in its topical analgesic and anti-inflammatory effects. Hopefully, we’ll see larger, more convincing research (double-blind, randomized, controlled trials) into the pain-relieving effects of topical medical cannabis, or its extracts, for all relevant health conditions.
- Cannabinoid Buccal Spray for Chronic Non-Cancer or Neuropathic Pain: A Review of Clinical Effectiveness, Safety, and Guidelines [Internet]. Ottawa (ON): Canadian Agency for Drugs and Technologies in Health; September 2016.
- Hammell DC, Zhang LP, Ma F, et al. Transdermal cannabidiol reduces inflammation and pain-related behaviours in a rat model of arthritis. Eur J Pain 2016;20:936-948.
- Giacoppo S, Galuppo M, Pollastro F, et al. A new formulation of cannabidiol in cream shows therapeutic effects in a mouse model of experimental autoimmune encephalomyelitis. Daru 2015;23:48.