Iguratimod Has No Established Role in Osteoarthritis Treatment
Iguratimod is not recommended for osteoarthritis because it is not mentioned in any major osteoarthritis treatment guidelines and has no clinical trial evidence supporting its use in this condition. The drug is approved and studied exclusively for rheumatoid arthritis, which is a fundamentally different disease process from osteoarthritis.
Why Iguratimod Is Not Appropriate for Osteoarthritis
Different Disease Mechanisms
Osteoarthritis is primarily a degenerative joint disease characterized by cartilage breakdown and mechanical wear, not the systemic autoimmune inflammation that defines rheumatoid arthritis 1.
Iguratimod's mechanism targets inflammatory cytokines and B-cell activity (TNF-α, IL-1β, IL-6, IL-8, IL-17) that drive rheumatoid arthritis pathology, not the mechanical and metabolic processes underlying osteoarthritis 2.
The drug inhibits osteoclastogenesis through RANKL and TNF-α signaling pathways, which is relevant for preventing bone erosions in rheumatoid arthritis but not for treating osteoarthritis cartilage degeneration 3, 4.
Absence from Osteoarthritis Guidelines
The 2019 American College of Rheumatology/Arthritis Foundation guideline for osteoarthritis management makes no mention of iguratimod or any similar disease-modifying antirheumatic drugs (DMARDs) 1.
The 2022 American Academy of Orthopaedic Surgeons guideline for knee osteoarthritis does not include iguratimod among recommended pharmacologic treatments 1.
Current osteoarthritis guidelines explicitly state that no effective disease-modifying agents have been identified for osteoarthritis, emphasizing that preventive strategies focus on weight management and injury prevention 1.
Established Osteoarthritis Treatment Instead
First-Line Recommendations
Exercise therapy (strengthening and aerobic fitness) is strongly recommended for all osteoarthritis patients, with supervised programs showing better outcomes 1, 5.
Weight loss for overweight/obese patients significantly reduces joint pain and mechanical stress 1, 5.
Acetaminophen up to 4,000 mg daily is the preferred initial oral analgesic due to favorable safety profile 1, 5.
Second-Line Pharmacologic Options
Topical NSAIDs before oral NSAIDs, particularly in elderly patients, provide effective pain relief with minimal systemic exposure 5.
Oral NSAIDs at the lowest effective dose for the shortest duration, always with proton pump inhibitor for gastroprotection 1, 5.
Intra-articular corticosteroid injections for acute pain exacerbations, especially with knee effusion, providing relief for approximately 3 months 1.
Critical Distinction
Iguratimod is a conventional synthetic DMARD (csDMARD) approved only for rheumatoid arthritis in Japan since 2012 and China, where it is used either as monotherapy or in combination with methotrexate 6, 7, 2. Its clinical development, all Phase II and III trials, and regulatory approvals have been exclusively for rheumatoid arthritis, not osteoarthritis 7.