Osteoarthritis: Daily use of CBD for the Treatment of Canine Osteoarthritis Pain

A randomized, double-blind, placebo-controlled study of daily cannabidiol for the treatment of canine osteoarthritis pain

D. Verrico, S. Wesson, V. Konduri, C. J. Hofferek, J. Vazquez-Perez, E. Blair, K. Dunner Jr, P. Salimpour, W. K. Decker, M. M. Halpert                 

2021

KEY TAKEAWAYS:

• 50 mg/day of CBD or 20 mg/day of liposomal CBD significantly reduced pain in dogs suffering from osteoarthritis
• Packaging CBD within a liposome (delivery method) forms liposomal CBD and improves CBD’s bioavailability and absorption 
• Movement indexes (standing, walking and running) were all improved after administration of both 50mg/day CBD and 20 mg/day liposomal CBD
• Dog’s quality of life increased after CBD treatment
• The study supports the safety and therapeutic potential of CBD for relieving arthritic pain and improving dog’s activity levels
• No detrimental impact of CBD administration was reported

OBJECTIVES & HYPOTHESIS → Pain is the primary symptom in osteoarthritis (OA); yet, current treatments are not curative and can be accompanied by significant adverse effects. The present study aimed to validate whether CBD might positively impact this disease and it went even further by comparing different delivery methods of CBD. As such, the main objectives of the study were to validate the capacity of a liposomally encapsulated CBD formulation to increase bioavailability in mice and in humans; and to determine the safety and therapeutic potential in pain reduction of CBD in a canine model. 

METHODS → First, using a lipopolysaccharide (LPS)-induced inflammation model, mice were treated with 10mg/mL of CBD, liposomal CBD, or liposomal D-luciferin or PBS (controls). To the in vivo study with humans, a longitudinal crossover study was performed to compare the bioavailability of liposomal vs naked CBD. Subjects were randomized regarding the order of which to receive naked CBD or liposomally encapsulated CBD and, 1 hour after, the circulating levels of CBD were determined. Finally, the veterinary study was a 4-week, randomized placebo-controlled trial in which both owner and veterinarian were blinded. 20 large (>20kg) dogs with a confirmed diagnosis of OA were randomly assigned to 1 of 4 groups: placebo; 20 mg/day (0.5 mg/kg) naked CBD; 50 mg/day (1.2 mg/kg) naked CBD; or 20 mg/day liposomal CBD. All other medications were discontinued and dogs were not allowed to receive any medications except the study one. Before treatment initiation and at day 30, dogs were evaluated by a veterinarian who assessed locomotion on a 5-point scale (5 best); owners also evaluated dogs before treatment and at weeks 4 and 6 using the Helsinki Chronic Pain Index (scale from 0 to 4). 

RESULTS → The relatively low bioavailability of CBD when administered orally may reduce its effectiveness. To potentially improve absorption of CBD isolate, it was packaged within liposomes, a vehicle delivery system that improves CBD’s uptake. In the LPS-inflammatory model, orally administered liposomal CBD began to significantly reduce rising TNF-a (inflammatory molecule involved in the pathogenesis of arthritis) levels within 1 hour of administration, whereas an additional hour was required before naked CBD significantly reduced rising TNF-a levels in comparison with negative controls. Moreover, liposomal CBD made a significantly greater impact on such levels. This enhanced bioavailability of liposomally encapsulated CBD was then validated in healthy human volunteers and results showed that the bioavailability of liposomal CBD was 17.1-fold greater than that of naked CBD. 

Moving to the veterinary study, assessment of animal’s symptoms was not significantly altered by administration of placebo or 20-mg/day naked CBD; however, administration of 50-mg/day naked CBD or 20 mg/day liposomal CBD generated statistically significant reductions in pain. This effect lasted for at least 15 days after cessation of therapy. 

Graphic 1: Pain scores in the 4 study groups 

Significant improvements of the 4 assessment categories (sitting to standing, lying to standing, walking, and running) were noted among dogs who received 50-mg/day naked CBD and 20-mg/day liposomal CBD. This amelioration was evidenced by group compilation of assessment scores and by considering only whether the symptoms worsened, remained the same, or improved over the course of therapy. 

Figure 1: Daily administration of CBD for 30 days improves veterinarian-perspective overall quality of life scores among large dogs with affirmative diagnosis of OA

The study also showed significant improvements to quality of life as quantified by both owners and veterinarian. No significant detrimental impact of CBD administration over the 4-week analysis period was reported. Therefore, this study supports the safety and therapeutic potential of hemp-derived CBD for relieving arthritic pain.