New Etoricoxib Study for OA Knees

“Fourteen days of etoricoxib 60 mg improves pain, hyperalgesia and physical function in individuals with knee osteoarthritis: a randomized controlled trial,” was the title of a new study published online in the August 1, 2017 edition of Osteoarthritis and Cartilage.

The study enrolled 80 community-recruited volunteers with painful knee osteoarthritis (OA) who were randomly assigned to either the active treatment or control (placebo) group.

Penny Moss, Ph.D., with the School of Physiotherapy and Exercise Science at Curtin University in Perth, Australia, and co-author, told OTW, “Our research group’s overall focus is to unravel some of the physiological mechanisms which drive chronic pain. Osteoarthritis pain is of particular interest to us as it has previously been seen as predictably ‘nociceptive,’ driven by joint damage and so quite straight-forward to manage. Yet it has become clear that for some people, osteoarthritic pain is far more complex, does not respond to standard exercise or pharmaceutical management and may not directly reflect measurable joint damage. This may be why a proportion of people report minimal pain relief even after the joint has been replaced.”

“Even though it is increasingly clear that osteoarthritis pain is heterogeneous, medicine still tends to have a ‘one size fits all’ approach to OA. Although prescribing guidelines are changing, intervention studies continue to assume that OA is a single condition and so apply a small number of largely subjective measures to evaluate efficacy.”

“This randomized, placebo-controlled study aimed to use a more comprehensive approach to evaluating the efficacy of a widely-used Cox-2 inhibitor over a relatively short time-frame of 14 days. This particular intervention was chosen because of the particular importance of targeting its application so that its benefits outweigh risks for an individual patient. Our approach was different in that we used an array of outcomes measures to assess change from baseline to Day 14.”

“In addition to standard self-report measures of pain, stiffness, function and quality of life (WOMAC [Western Ontario and McMaster Universities Osteoarthritis Index] and SF [Short Form] 36), we included self-report of neuropathic-type symptoms (PainDETECT and PQAS [Pain Quality and Assessment Scale]), objective assessment of physical function changes and objective measurement of pain sensitivity using quantitative sensory testing.”

“Etoricoxib clearly reduced participants’ pain with just a 14-day course, whether that was measured as subjective change in everyday pain or as change in evoked pain sensitivity. Interestingly, pain sensitivity was reduced even at sites distant from the OA knee, suggesting more than just a localized anti-inflammatory effect. We were particularly interested to find significantly reduced self-reported neuropathic-type symptoms as well.”

“It may be that Cox-2 NSAIDs [nonsteroidal anti-inflammatory drugs] have a more centralized effect than has been previously understood, however more data is needed to support or refute this finding. Certainly, just a short course had significant effects on pain, neuropathic-type pain, both local and widespread pain sensitivity and physical function. Although this study was not powered to stratify according to type of pain (neuropathic, nociceptive), there was clearly a range of responses amongst participants, suggesting that identification of pain type may be an important factor when deciding upon the most effective pain-relief approach for each individual. Further work is clearly needed.”

“Not all OA pain is nociceptive or simple, meaning that joint replacement may not be the best solution for all OA sufferers. Despite its understandably bad press, the benefits of Cox-2 NSAIDs may outweigh the risks in some individuals. Regardless, we need to thinking about a more comprehensive approach to the assessment of pain and function in people with OA pain so that we can stratify and treat most appropriately.”