What are the treatment options for a patient with ankylosing spondylitis?

Treatment Options for Ankylosing Spondylitis

Optimal management of ankylosing spondylitis requires combining non-pharmacological treatments (patient education and regular exercise) with NSAIDs as first-line pharmacological therapy, escalating to anti-TNF biologics for patients with persistently high disease activity despite conventional treatment. 1

Initial Treatment Approach

Non-Pharmacological Foundation (Essential for All Patients)

Non-pharmacological and pharmacological treatments are complementary and both must be initiated together from the start. 1

Patient education and regular exercise are mandatory cornerstone treatments that must continue throughout the entire disease course. 1, 2

• Home exercise programs improve function in the short term with Level Ib evidence supporting their use. 1
• Supervised group physiotherapy demonstrates superior patient global assessment outcomes compared to home exercise alone, though both improve function similarly. 1, 2
• Individual and group physical therapy should both be considered, with group therapy showing better patient-reported outcomes. 1
• Patient associations and self-help groups may provide additional support. 1

First-Line Pharmacological Treatment

NSAIDs are the first-line drug treatment for all patients with ankylosing spondylitis presenting with pain and stiffness. 1, 2

• NSAIDs demonstrate Level Ib evidence for improving spinal pain, peripheral joint pain, and physical function over 6-week periods. 1
• Continuous NSAID treatment is preferred over intermittent "on-demand" use for patients with persistent active symptomatic disease, as one RCT suggests continuous treatment may retard radiographic disease progression at 2 years. 1
• No single NSAID preparation has been shown to be clearly superior to others in comparative studies. 1

For patients with increased gastrointestinal risk, use either non-selective NSAIDs plus a gastroprotective agent (PPIs reduce serious GI events by 60%) OR selective COX-2 inhibitors (reduce serious GI events by 82% compared to traditional NSAIDs). 1, 2

• Both traditional NSAIDs and COX-2 inhibitors demonstrate equivalent efficacy for spinal pain relief. 1
• Consider cardiovascular risk factors when selecting between NSAIDs and COX-2 inhibitors, as emerging evidence suggests both may carry cardiovascular toxicity. 1

Second-Line and Adjuvant Therapies

Analgesics for Breakthrough Pain

Analgesics (paracetamol, opioids) should be considered for pain control when NSAIDs are insufficient, contraindicated, or poorly tolerated. 1, 2

• Paracetamol demonstrates GI toxicity not significantly higher than placebo in Level 1a studies. 1

Local Corticosteroid Injections

Corticosteroid injections directed to local sites of musculoskeletal inflammation may be considered for enthesopathy or sacroiliac joint pain. 1, 2

• Sacroiliac joint injections should be performed under fluoroscopic control or CT guidance. 3

Disease-Modifying Antirheumatic Drugs (DMARDs)

DMARDs, particularly sulfasalazine, are indicated for patients with peripheral arthritis involvement or longstanding severe/refractory disease. 3, 4

• Sulfasalazine shows beneficial results mainly in AS patients with peripheral disease involvement. 3
• Methotrexate may be continued during treatment if necessary, though evidence is less robust than for sulfasalazine. 3, 4

Biologic Therapy for Refractory Disease

Anti-TNF treatment should be initiated in patients with persistently high disease activity despite conventional treatments (NSAIDs, exercise, and DMARDs if peripheral involvement). 5, 2

FDA-Approved Anti-TNF Agents

Adalimumab (HUMIRA) is indicated for reducing signs and symptoms in adult patients with active ankylosing spondylitis, administered at 40 mg subcutaneously every other week. 6

• NSAIDs and/or analgesics may be continued during anti-TNF treatment. 6
• Critical safety consideration: Test all patients for latent tuberculosis before initiating anti-TNF therapy and monitor closely for serious infections. 6, 7

Etanercept (Enbrel) is indicated for reducing signs and symptoms in patients with active ankylosing spondylitis, administered at 50 mg weekly subcutaneously. 7

• Methotrexate, glucocorticoids, salicylates, NSAIDs, or analgesics may be continued during treatment. 7
• Doses higher than 50 mg per week are not recommended based on higher adverse reaction incidence without improved efficacy. 7

Evidence for Anti-TNF Efficacy

Etanercept, infliximab, and adalimumab demonstrate significant reduction in disease activity, pain, and stiffness in randomized placebo-controlled trials, with improvements in function, spinal movement, and quality of life. 8

• Response to anti-TNF therapy is greater in patients with earlier disease and less structural damage. 8
• Long-term studies are needed to determine if these agents prevent radiologic progression and ankylosis. 8

Surgical Intervention

Total hip arthroplasty should be considered in patients with refractory pain or disability and radiographic evidence of structural damage, independent of age. 5, 2

Spinal surgery (corrective osteotomy and stabilization procedures) may be indicated for selected patients with:

• Fixed kyphotic deformity affecting balance and horizontal vision 5, 2
• Segmental instability from spinal pseudarthrosis or Andersson lesion 5
• Severe instability causing pain 4
• Neurological deficiency 4

AS-specific surgical considerations include careful management of spinal fractures and atlantoaxial instability. 4

Disease Monitoring Strategy

Monitor disease activity every 2-6 months depending on symptoms, severity, and drug treatment using the ASAS core set, which includes:

• Physical function (BASFI or Dougados Functional Index) 1, 2
• Pain assessment (VAS for spine pain) 1
• Spinal mobility (chest expansion, modified Schober, occiput-to-wall distance) 1
• Patient global assessment 1
• Morning stiffness duration 1
• Acute phase reactants (ESR) 1

Radiographic monitoring is generally not needed more often than once every 2 years, though exceptions exist for rapidly progressing cases where syndesmophytes may develop within 6 months. 1, 5, 2

Critical Pitfalls to Avoid

• Do not delay anti-TNF therapy in patients with persistently high disease activity despite adequate trials of NSAIDs and exercise, as earlier intervention shows better response rates. 8
• Never initiate anti-TNF therapy without screening for latent tuberculosis, as reactivation of TB is a serious risk. 6, 7
• Do not use systemic corticosteroids as routine therapy in AS, as their role is limited compared to rheumatoid arthritis; reserve for specific subgroups or local injection. 4
• Avoid discontinuing exercise programs even when pharmacological therapy is optimized, as non-pharmacological treatments remain essential throughout the disease course. 1