The first human study on the efficacy of topical CBD for the treatment of thumb basal joint arthritis-related pain published in May in the Journal of Hand Surgery found that topical CBD brings significant improvements in pain and disability without side effects.
The opioid crisis has driven scientists into exploring more effective and safer solutions in the treatment of chronic pain, and CBD has become a serious candidate for such a role. Pain remains the main reason why consumers reach out to CBD products. In a 2021 survey of 253 participants, where 62.0% reported trying a CBD product, the majority responded that these products have helped their pain (59.0%) and allowed them to reduce their pain medications (67.6%), including opioids (53.7%).
Patients with thumb basal joint arthritis seem to be no exception. In a survey of 103 patients, 69% were interested in trialing oral CBD and 80% were interested in trialing topical CBD for the treatment of their arthritis-related thumb pain. Twelve of the 25 oral CBD users and seven of 21 topical CBD users believed that the products were effective in relieving pain, and worth the financial costs.
Basal thumb arthritis is a type of osteoarthritis affecting the base of the thumb. It can cause severe pain, swelling, and decreased strength and range of motion, making it difficult for patients to conduct the simplest tasks, like opening the doors or jars. It is a common disease, affecting up to 15% of the population older than 30 years.
Animal studies have already shown the promising effects of topically applied CBD for osteoarthritis. CBD exerts increased regional bioavailability and better results without reported side effects when applied transdermally. The maximum absorption and efficacy dose in rats was found to be 6.2 mg per day, which is approximately 21 mg per kg per day.
Cannabinoids have already been found to reduce arthritic pain in humans when taken orally. Sativex, a mouth (oromucosal) spray containing 1:1 CBD and THC, was used in the first-ever controlled trial of the efficiency of cannabinoids in the treatment of rheumatoid arthritis pain. The study was conducted in 2005 by scientists from the Royal National Hospital for Rheumatic Diseases in Bath, UK. The trial on 58 patients found a significant analgesic effect and disease activity was significantly suppressed.
60% reduction in pain and a 39% reduction in disability
The study conducted by scientists from the Department of Plastic Surgery of the University of Virginia is the first human study that looked into the efficacy of topical CBD for the treatment of thumb basal joint arthritis-related pain. The results are encouraging – it found that topical CBD treatment demonstrates significant improvements in thumb basal joint arthritis-related pain and disability without side effects.
In phase 1, a skin test on 10 healthy participants was completed after one week of monitoring the effects of twice daily application of 1 mL of topical CBD (6.2 mg/mL) with shea butter. The dose is the highest concentration allowed for this study by the FDA. There were no adverse events, so scientists proceeded with a phase 2, double-blinded, randomized controlled trial.
Eighteen participants with symptomatic thumb basal joint arthritis were randomized to two weeks of twice-daily treatment with CBD (6.2 mg/mL CBD with shea butter) or shea butter alone, followed by a one-week washout period, and then crossover for two weeks with the other treatment. They recorded skin changes in a symptom diary for any side effects and were evaluated two weeks later. The evaluation included skin surveillance, vital signs, physical exam, outcome measures, C-SSRS scores, symptom diary evaluation, and laboratory tests. After the week-long washout period, participants were given the other cream for crossover, using the same application method. The endpoints were recorded two weeks later, and the final study endpoints followed after another one-week washout period when the study was completed.
As a result, there was a 60% reduction in pain and a 39% reduction in disability with the application of CBD cream. Additionally, there was a 16% increase in general well-being. This protocol found no significant difference in patient physical parameters, including grip strength, pinch strength, or thumb range of motion.
These results are comparable in success to a 2019 study on the effects of transdermal application of CBD for myofascial pain. In that randomized controlled trial on 60 patients, topical application of 67 mg of CBD and other minor cannabinoids twice-daily for 14 days reduced pain by 70.2% in the CBD treatment group. Another clinical trial that included topical administration of CBD has shown promising results in the treatment of pain and other disturbing sensations in patients with peripheral neuropathy.
Reviewed by Sasha Bajilo, founder of ILESOL Pharmaceuticals, an industrial scale producer of CBD products and formulations. Expert on Hemp/Cannabis policy, member of the Croatian Ministry of Health regulatory commission for medical cannabis.