What you need to know
A 2021 study systematically reviewed evidence from nearly 200 clinical trials on the effectiveness and safety of available painkiller drugs used in the treatment of osteoarthritis, including 90 different drug formulations and dosages. Diclofenac applied to the skin appeared to be the best option for knee osteoarthritis. Importantly, the potential harms of opioid treatment were found to outweigh any benefits.
What is this research about?
More than 4 million Canadians live with osteoarthritis. It has no cure, so current treatments mainly focus on pain relief. Most people with osteoarthritis are prescribed nonsteroidal anti-inflammatory drugs (NSAIDs) or opioids as painkillers. Opioids are still prescribed often despite known risks of harm. An evaluation of which individual painkiller drugs – at which doses, and in which forms – offer the best balance of safety and effectiveness was needed to guide clinical practice.
What did the researchers do?
Dr. Bruno da Costa and his team, including postdoctoral fellow Dr. Pavlos Bobos, are performing an extensive critical analysis of high-quality clinical evidence on all major nonsurgical treatment approaches for osteoarthritis. In this study, they used advanced statistical techniques to analyze data published over decades from more than 100,000 patients with osteoarthritis treated with NSAIDs, opioids, or acetaminophen for pain relief. This allowed them to estimate the benefits and harms of each treatment.
What did they find?
Of the 90 different treatments assessed, two NSAID pills (etoricoxib 60 mg/day and diclofenac 150 mg/day) were suggested to be among the best options for most people with osteoarthritis, although not for long-term use or for people with certain other health conditions. For people with knee osteoarthritis, the best option was found to be diclofenac (70-81 mg/day) applied to the skin, although this was not studied for other joints. In the case of all opioids studied, the potential for harm outweighed the benefits.
How can this research be used?
This research provides a much-needed up-to-date evidence base to guide the development of clinical practice guidelines to help doctors and patients choose the best option from the wide array of available treatments for osteoarthritis pain. It also challenges the use of opioids – which can increase the risk of bone fractures, heart problems, opioid dependency, and death – for the management of osteoarthritis pain.
As a person diagnosed with severe osteoarthritis at a young age, the long-term use of pain medications and their respective side effects are concerning. Finding alternatives and safer ways to manage pain for the long-term is important and this research could help identify alternative strategies for the management of osteoarthritis.”
— Lisa Ewasiuk, Arthritis Society Online Consumer Panel Member
What impact could this have?
This research, which was published in a high-impact medical journal, has already made an impression on the research and medical communities, having been accessed online more than 25,000 times and mentioned on social media more than 200 times.
By providing medical professionals with the evidence synthesis needed to inform science-driven clinical practice guidelines, this body of work will help shape the future of precision medicine for osteoarthritis – choosing the right treatment, for the right patient, at the right time. Treatment plans using the lowest effective dose of a painkiller with the lowest risk of harmful side effects for an individual patient’s overall health circumstances could ultimately be life-changing.
About the researcher
Dr. Bruno da Costa is a clinical epidemiologist and biostatistician. In 2017, he established his research program on comparative treatment effectiveness as a scientist at St. Michael’s Hospital and an associate professor at the University of Toronto. The Arthritis Society proudly supported Dr. da Costa in these early days of his career with a Young Investigator Operating Grant. Dr. Pavlos Bobos is a postdoctoral fellow supported by an Arthritis Society Training Award.
“We found that even maximum recommended daily doses of opioids do not have a relevant effect on osteoarthritis pain. It was also interesting to see that lower doses of the topical NSAID diclofenac (like Voltaren) have a similar beneficial effect to the most effective oral NSAIDs in knee osteoarthritis, but would be safer than pills for patients with gastrointestinal or cardiovascular conditions, or those who are frail.”
— Dr. Bruno da Costa, St. Michael’s Hospital
da Costa BR, Pereira TV, Saadat P, Rudnicki M, Iskander SM, Bodmer NS, Bobos P, Gao L, Kiyomoto HD, Montezuma T, Almeida MO, Cheng PS, Hincapié CA, Hari R, Sutton AJ, Tugwell P, Hawker GA, Jüni P. Effectiveness and safety of non-steroidal anti-inflammatory drugs and opioid treatment for knee and hip osteoarthritis: network meta-analysis. BMJ. 2021;375:n2321.
Research at the Arthritis Society
Through the trust and support of our donors and partners, the Arthritis Society is Canada’s largest charitable funder of cutting-edge arthritis research, investing over $220 million in research projects since our founding. These projects have led to breakthroughs in the diagnosis, treatment and care of people with arthritis. Visit us at arthritis.ca/research.