Terminated prematurely due to feasibility issues with rate of recruitment

Randomized controlled trial regarding the efficacy of a multimodal topical analgesic, Multiprofen, in comparison to placebo cream treatment on knee pain and function in patients with knee osteoarthritis.

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.

Secondary objectives

Our secondary objectives will be to evaluate the effect of topical combination therapy on:

1. Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) patient reported outcome score. This score is commonly utilized in assessment of knee osteoarthritis and has been validated to be reliable and responsive in this patient population.
2. Patient knee range of motion and strength
3. Return to previous level of activity
4. Radiographic degree of osteoarthritis.
5. Patient demographics
6. Adverse events

SUMMARY OF TRIAL DESIGN The investigators propose a single center blinded trial evaluating the efficacy of a combination formula of topical analgesic in comparison to placebo cream treatment. The investigators will randomize 186 patients between topical multimodal cream "multiprofen" and a control placebo cream.

Randomization Method Participants will be randomized using a random number generator to either experimental or placebo control intervention.

Participants will be randomized to one of two treatments:

Experimental - A multimodal topical cream treatment with Ketoprofen, Baclofen, Amitryptiline, and lidocaine in a carrier gel. This topical formulation has been in use commercially under the trade name "Multi-profen".

Control - A identically packaged placebo cream treatment will be utilized in the control population.

Proposed duration of treatment and follow-up: Participants will be brought back at 3,6 and 12 weeks' time to complete questionnaires recording VAS and WOMAC scores

The current proposal includes 1 clinical site in Canada (Oakville Trafalgar Memorial Hospital, Oakville, ON, CAN)

Inclusion Criteria:

The inclusion criteria are:

1. adult men or women ages 50-80 years;
2. Diagnosis of symptomatic osteoarthritis of the knee based on clinical and radiographic criteria;
3. provision of informed consent.

Exclusion Criteria:

The exclusion criteria are:

1. patients with inflammatory osteoarthritis;
2. open wounds or sores over the knee joint;
3. patients that will likely have problems, in the judgment of the investigators, with maintaining follow-up;
4. Cases involving litigation.

Patients will be randomized using a random number generator to either intervention. Interventions will be identically packaged and labeled either A or B by a pharmacist who will be uninvolved with the trial administration. Participants and study personnel will be blinded to the treatment groups.