What is the initial treatment for ankylosing spondylitis?

Initial Treatment for Ankylosing Spondylitis

NSAIDs are strongly recommended as the first-line therapy for ankylosing spondylitis (AS), with approximately 75% of patients showing a good response within 48 hours. 1

Treatment Algorithm

First-Line Treatment

• NSAIDs
  • Should be used as initial therapy for all patients with active AS
  • No specific NSAID is universally preferred; selection should be based on:
    • Patient response
    • Comorbidities
    • Side effect profile
  • Most patients (75%) show good response within 48 hours 1
  • Consider continuous use during periods of active disease

Second-Line Treatment (If inadequate response to NSAIDs)

• TNF Inhibitors (TNFi)
  • Options include adalimumab, infliximab, golimumab, and certolizumab pegol
  • Approximately 50% of patients achieve 50% improvement 1
  • Special considerations:
    • For concomitant inflammatory bowel disease: Use TNFi monoclonal antibodies (adalimumab, infliximab, golimumab, certolizumab) rather than etanercept 1
    • For recurrent iritis: Consider TNFi monoclonal antibodies over etanercept 1

Alternative Biologics (If TNFi failure)

• IL-17 Inhibitors
  • Secukinumab has demonstrated efficacy in clinical trials
  • In AS clinical trials, secukinumab showed significant improvements in ASAS20 and ASAS40 responses compared to placebo 2
  • Effective regardless of prior TNFi use 2

For Peripheral Joint Involvement

• Sulfasalazine
  • Limited efficacy for axial symptoms but may be effective for peripheral arthritis 1

Non-Pharmacological Treatment (Should accompany drug therapy)

• Physical Therapy
  • Strongly recommended alongside pharmacological treatment
  • Helps reduce stiffness and prevent spinal ankylosis
  • Improves physical function and quality of life 1

Monitoring Treatment Response

• Regular assessment of disease activity using validated tools:
  • Bath Ankylosing Spondylitis Disease Activity Index (BASDAI)
  • Ankylosing Spondylitis Disease Activity Score (ASDAS)
• Monitor inflammatory markers (ESR, CRP), though they may not always correlate with disease activity 1

Important Considerations

• Early diagnosis and treatment are crucial to prevent structural deformities and reduce mortality risk 1
• Patients with AS have increased mortality risk compared to the general population, which can be mitigated with adequate treatment 1
• Radiographic follow-up is not necessary more frequently than every 2 years unless significant clinical changes occur 1
• Screen for common comorbidities: uveitis, inflammatory bowel disease, and psoriasis 1

Common Pitfalls to Avoid

• Delaying effective treatment, which can lead to irreversible structural damage
• Failing to try an adequate dose of NSAIDs before moving to biologics
• Overlooking non-pharmacological interventions like physical therapy
• Not considering comorbidities when selecting treatment (especially IBD and recurrent iritis)
• Using etanercept in patients with concomitant IBD or recurrent iritis

While older evidence supported phenylbutazone as the NSAID of choice 3, current guidelines do not specify a preferred NSAID, as efficacy appears similar across the class with individual patient response being the determining factor 1, 4.