FRI0299 Methotrexate: A therapeutic option in symptomatic knee osteoarthritis: Randomized placebo-controlled trial

Background

Osteoarthritis (OA) is a common disabling condition, for which no effective therapy currently exists. Synovitis is commonly demonstrated in knee OA imaging. Synovial inflammation due to the release of prostaglandins and cytokines is an important cause of pain. Methotrexate (MTX) helps to decrease synovitis in many inflammatory joint diseases, particularly rheumatoid arthritis.

Objectives

To assess the efficacy of MTX in decreasing pain and inflammation in symptomatic knee OA.

Methods

Eighty-eight patients with American College of Rheumatology (ACR) clinical and radiographic criteria of primary knee OA with knee pain, [>4 on the 24-hour average pain severity scale (0-10) using mean of daily ratings from week preceding randomization] for >14 days/month during 3 consecutive months preceding enrollment were included in this randomized double-blind placebo-controlled trial. Exclusion criteria included any other inflammatory conditions, hepatic and renal insufficiency. Patients meeting the eligibility criteria were randomized in a 1:1 ratio to receive either 25mg/week oral MTX (n=44) or placebo (n=44) together with their usual therapy provided the dosages were kept constant for 16 weeks. The primary outcome measure was pain reduction and secondary outcome measures included improvements in physical function scores. Pain was assessed using the Visual Analogue pain Scale, (VAS, 0-100 mm). Functional assessment was performed using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and Activities of daily living (ADL) scores. Alterations in dosage of analgesic/NSAID drugs used were recorded. Safety and tolerability were also assessed. Synovitis was detected by ultrasound imaging at baseline and at the end of the study.

Results

There was a statistically significant reduction in pain in the MTX group compared to the placebo group, p=0.007. In addition, there was a significant improvement in WOMAC and ADL scores at 16 weeks in the intervention group versus the placebo group as well as statistically significant improvement in patient and physician assessment of pain. NSAID use was significantly less in the MTX versus the placebo group, p=0.055. Statistically significant improvement in synovitis, as detected by ultrasound, occurred in the MTX group compared to the placebo group at 16 weeks. No serious side effects were reported.

Conclusions

MTX significantly reduced pain and improved synovitis. In addition, there was a significant improvement in physical function. MTX may be a therapeutic option in the treatment of pain and inflammation related to OA. However, further large scale longitudinal studies are needed to confirm these results.

Disclosure of Interest

None Declared