Trial Evaluating multimOdal toPical Cream In CompArison to pLacebo (TOPICAL)

Knee osteoarthritis (OA) is a disease with a high global burden, and multiple conservative treatment options are available. In addition to being a major source of disability osteoarthritis results in a significant economic burden as well. A study published in 2012 showed the 1-year physician, outpatient procedure, and hospitalization costs in patients with osteoarthritis more than double those patients without osteoarthritis in Ontario.

Conservative treatment options include topical and oral anti-inflammatory medications, weight loss, physiotherapy and intra articular cortisone and viscosupplementation injections. Unfortunately, commonly used treatments such as oral anti-inflammatory medications carry a significant systemic adverse effect on the gastrointestinal (GI) tract and hepatic and renal systems and intra articular cortisone have potential adverse effect on blood glucose control. For this reason, topical anti-inflammatory medications are popular yet are often ineffective. Unfortunately, topical anti-inflammatory medications have variable efficacy in relieving osteoarthritic knee pain and often only provide a moderate degree of pain relief.

In the setting of chronic pain various other topical modalities have been utilized. A systematic review of the literature identified commonly studied topical analgesics were nonsteroidal anti-inflammatory drugs followed by lidocaine, capsaicin, amitriptyline, glyceryl trinitrate, opioids, menthol, pimecrolimus, and phenytoin. Given the biological bases behind utilizing agents which target a variety of pain generators the investigators hypothesized that a combination of these would provide significant pain relief to patients affected by end stage knee osteoarthritis. For this reason, the investigators propose a trial evaluating utilizing multiple topical modalities for pain relief to provide support for the use of combination therapy in treating knee osteoarthritis. Results from this study will potentially improve the global health and economic burden through improvement in the management of knee osteoarthritis.

STUDY OBJECTIVES

Primary objective The primary objective of the trial will be to evaluate the efficacy of a multimodal topical analgesic, Multiprofen, in comparison to placebo cream treatment on patient reported pain relief utilizing a 11-point visual analog scale (VAS) measured from 0-10.