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: NSAIDs and Physical Therapy

NSAIDs as Primary Pharmacotherapy

• NSAIDs are strongly recommended as the initial drug treatment for all patients with active AS presenting with pain and stiffness. 1
• Administer NSAIDs continuously rather than on-demand for patients with persistently active, symptomatic disease, as continuous therapy may slow radiographic progression. 1, 2
• If the first NSAID fails after 2-4 weeks at full dose, switch to a different NSAID before declaring treatment failure. 3
• Approximately 75% of AS patients demonstrate good or very good response to full-dose NSAIDs within 48 hours, which helps distinguish AS from mechanical back pain. 1

NSAID Selection Based on Risk Profile

• For patients with increased gastrointestinal risk, use either non-selective NSAIDs plus a proton pump inhibitor, or a selective COX-2 inhibitor. 1, 2
• COX-2 selective NSAIDs (coxibs) reduce serious GI events by 82% compared to traditional NSAIDs (RR 0.18,95% CI 0.14-0.23). 1
• Consider cardiovascular risk factors when selecting NSAIDs, as cardiovascular toxicity appears to be a class effect. 2

Physical Therapy: Non-Negotiable Component

• Physical therapy and regular exercise are strongly recommended as fundamental elements of treatment for all AS patients. 1, 2
• Supervised physical therapy programs are more effective than home exercises alone. 2
• Patient education should accompany exercise programs; consider referral to patient associations and self-help groups. 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
• Approximately 50% of NSAID-refractory patients achieve at least 50% improvement with TNF inhibitors, with 72% response rate in patients with disease duration <10 years. 1

TNF Inhibitor Selection Algorithm

• No particular TNF inhibitor is preferred for standard AS, except in specific clinical scenarios. 1
• For patients with concomitant inflammatory bowel disease, strongly prefer TNF inhibitor monoclonal antibodies (adalimumab, infliximab) over etanercept. 1
• For patients with recurrent iritis, use TNF inhibitor monoclonal antibodies rather than etanercept. 1
• FDA-approved TNF inhibitors for AS include adalimumab (40 mg subcutaneously every other week) and etanercept (50 mg subcutaneously weekly). 4, 5

Critical Safety Monitoring for TNF Inhibitors

• Test all patients for latent tuberculosis before initiating TNF inhibitor therapy and periodically during treatment. 4, 5
• Monitor closely for serious infections including tuberculosis reactivation, invasive fungal infections (histoplasmosis, coccidioidomycosis), and opportunistic infections. 4, 5
• Be aware of increased lymphoma risk, particularly hepatosplenic T-cell lymphoma in young males receiving concomitant azathioprine or 6-mercaptopurine. 4, 5
• Complete all age-appropriate vaccinations before starting TNF inhibitor therapy. 5

Treatments to Avoid

Systemic Glucocorticoids

• Strongly recommend against systemic glucocorticoids for axial disease in AS. 1
• Local corticosteroid injections may be considered for peripheral arthritis or enthesitis. 1

Traditional DMARDs for Axial Disease

• Do not use sulfasalazine or methotrexate for axial manifestations of AS, as there is no evidence of efficacy. 1
• Sulfasalazine may be considered only for patients with peripheral arthritis. 1

Surgical Interventions

Hip Arthroplasty

• Strongly recommend total hip arthroplasty for patients with advanced hip arthritis causing refractory pain or disability with radiographic evidence of structural damage, regardless of age. 1

Spinal Surgery

• Consider spinal corrective osteotomy and stabilization procedures in selected patients with severe disabling deformity. 1, 2

Adjunctive Analgesics

• Analgesics such as paracetamol and opioids may be considered for residual pain in patients where NSAIDs are insufficient, contraindicated, or poorly tolerated. 1, 3
• These should not replace NSAIDs as primary therapy but serve as supplemental pain control. 1

Disease Monitoring Strategy

• Monitor disease activity using patient history, clinical parameters (pain, function, spinal mobility), laboratory tests (CRP, ESR), and imaging according to the ASAS core set. 1
• Adjust treatment if therapeutic goals are not met, with clinical remission/inactive disease as the primary target. 3
• Assess for extra-articular manifestations and manage in collaboration with appropriate specialists. 2
• Monitor for increased cardiovascular disease risk and osteoporosis. 2

Common Pitfalls to Avoid

• Do not discontinue NSAIDs after achieving clinical improvement; continue long-term therapy to potentially slow structural progression. 2, 6
• Do not delay TNF inhibitor initiation in patients with inadequate NSAID response, as earlier treatment (disease duration <10 years) shows better outcomes. 1
• Do not prescribe etanercept for AS patients with inflammatory bowel disease, as monoclonal antibodies are superior. 1
• Do not use systemic corticosteroids for axial symptoms, despite their effectiveness in other inflammatory arthritides. 1