What are the treatment options for ankylosing spondylitis?

Treatment Options for Ankylosing Spondylitis

Start all patients with active ankylosing spondylitis on NSAIDs as first-line therapy combined with physical therapy, and escalate to TNF inhibitors if disease activity persists despite adequate NSAID treatment. 1

First-Line Treatment Algorithm

NSAIDs (Strongly Recommended)

• NSAIDs are the cornerstone of pharmacological treatment for patients with active AS presenting with pain and stiffness. 1
• Continuous daily NSAID therapy is preferred over on-demand dosing for patients with persistently active, symptomatic disease. 1
• If the first NSAID fails after 2-4 weeks at adequate dosing, switch to a different NSAID before declaring treatment failure. 2
• 75% of AS patients demonstrate good or very good response to full-dose NSAIDs within 48 hours, distinguishing inflammatory from mechanical back pain. 1
• For patients with gastrointestinal risk factors, use either a COX-2 selective inhibitor or combine a non-selective NSAID with a proton pump inhibitor for gastroprotection. 1

Physical Therapy (Strongly Recommended)

• All patients diagnosed with AS must be referred for structured exercise programs and physical therapy. 1, 3
• Supervised physical therapy with group or individual sessions is more effective than home exercises alone, though home exercises remain beneficial and should be recommended to all patients. 1, 3
• Patient education about the disease and regular exercise form the foundation of non-pharmacological management. 1

Second-Line Treatment: TNF Inhibitors

Indications for TNF Inhibitor Therapy

• Initiate TNF inhibitor therapy in patients with persistently high disease activity despite adequate NSAID treatment. 1
• There is no requirement to trial DMARDs (such as sulfasalazine or methotrexate) before starting TNF inhibitors for axial disease. 1
• TNF inhibitors show Level Ib evidence for improving spinal pain, function, inflammatory biomarkers, and MRI-detected spinal inflammation. 4

TNF Inhibitor Selection

• No particular TNF inhibitor is preferred for standard AS, with the critical exception of patients with concomitant inflammatory bowel disease or recurrent iritis. 1
• For AS patients with inflammatory bowel disease, use TNF inhibitor monoclonal antibodies (infliximab, adalimumab) rather than etanercept, as etanercept lacks efficacy for bowel inflammation. 1, 5
• For AS with recurrent iritis, similarly prefer monoclonal antibodies over etanercept. 1

Dosing for TNF Inhibitors

• Etanercept: 50 mg subcutaneously once weekly for AS. 6
• Adalimumab: 40 mg subcutaneously every other week for AS. 5
• Methotrexate, glucocorticoids, NSAIDs, or analgesics may be continued during TNF inhibitor treatment. 6, 5

Treatments NOT Recommended

Systemic Glucocorticoids (Strong Recommendation Against)

• Do not use systemic corticosteroids for axial disease in AS, as there is no evidence supporting efficacy. 1
• Local corticosteroid injections directed at specific sites of musculoskeletal inflammation may be considered for peripheral arthritis or enthesitis. 1

Traditional DMARDs for Axial Disease

• Sulfasalazine and methotrexate have no proven efficacy for axial manifestations of AS. 1
• Sulfasalazine may be considered only for patients with peripheral arthritis as a component of their AS. 1

Adjunctive and Rescue Therapies

Analgesics

• Paracetamol (acetaminophen) and opioids may be used for pain control in patients where NSAIDs are insufficient, contraindicated, or poorly tolerated. 1
• These should be considered adjunctive rather than primary therapy. 2

Surgical Interventions

Hip Arthroplasty

• Total hip arthroplasty is strongly recommended for AS patients with advanced hip arthritis causing refractory pain or disability with radiographic evidence of structural damage, regardless of age. 1

Spinal Surgery

• Spinal corrective osteotomy and stabilization procedures may be valuable in selected patients with severe disabling deformity. 1, 3

Disease Monitoring Strategy

• Monitor disease activity using patient history, clinical parameters (including ASAS core set), laboratory tests (CRP, ESR), and imaging according to clinical presentation. 1
• Frequency of monitoring should be individualized based on symptoms, disease severity, and current drug treatment. 1
• Treatment goals should focus on controlling symptoms and inflammation, preventing structural damage, preserving function, and maximizing quality of life. 3

Common Pitfalls to Avoid

• Do not delay TNF inhibitor initiation in patients with inadequate NSAID response—earlier treatment (disease duration <10 years) shows better response rates, with 72% achieving ≥50% improvement. 1
• Do not prescribe systemic corticosteroids for axial symptoms, as this lacks evidence and exposes patients to unnecessary risks. 1, 3
• Do not require DMARD failure before TNF inhibitor use for axial disease, as DMARDs are ineffective for spinal involvement. 1
• Do not use etanercept in AS patients with inflammatory bowel disease, as it may worsen bowel inflammation. 1
• Do not underestimate the importance of continuous physical therapy, as this is as fundamental as pharmacological treatment. 1, 3