What is the treatment for ankylosing spondylitis?

Treatment of Ankylosing Spondylitis

Start with NSAIDs as first-line therapy, escalate to TNF inhibitors if disease remains active despite NSAID treatment, and ensure all patients receive physical therapy. 1

First-Line Treatment: NSAIDs

NSAIDs are strongly recommended as the initial pharmacological treatment for all patients with active ankylosing spondylitis. 1 Use the lowest effective dose initially 2, and if the first NSAID fails after 2-4 weeks, switch to a different NSAID before declaring treatment failure 2.

• NSAIDs provide rapid efficacy on inflammatory symptoms, with 75% of patients showing good response within 48 hours 2
• All NSAIDs demonstrate significant efficacy in reducing pain severity (mean differences between -17.49 and -25.99 compared to placebo), improving function (BASFI), and achieving ASAS20 response 3
• Etoricoxib ranks as the most efficacious NSAID based on network meta-analysis 3
• Continuous NSAID therapy is preferred over intermittent use for patients with persistent, active disease 4
• Common gastrointestinal side effects occur with diclofenac and naproxen; consider COX-2 selective inhibitors to reduce GI toxicity 5, 3

Essential Non-Pharmacological Treatment

Physical therapy is strongly recommended for all patients with AS and should be initiated immediately upon diagnosis. 1

• Refer all patients to a specialist for a structured exercise program 2
• Home exercises are effective and should be recommended to all patients 2
• Physical therapy improves pain, function, and may help prevent progressive spinal fusion 6

Second-Line Treatment: TNF Inhibitors

For patients with persistently active disease despite adequate NSAID therapy, TNF inhibitors are strongly recommended. 1

TNF Inhibitor Selection

• No particular TNF inhibitor is preferred for standard AS 1
• For patients with concomitant inflammatory bowel disease, use TNF inhibitor monoclonal antibodies (adalimumab, infliximab) rather than etanercept 1, 4, 7
• For patients with recurrent iritis, TNF inhibitor monoclonal antibodies are also preferred 1
• Adalimumab is FDA-approved for reducing signs and symptoms in adults with active AS, dosed at 40 mg subcutaneously every other week 7
• Etanercept is FDA-approved for reducing signs and symptoms in adults with active AS, dosed at 50 mg subcutaneously weekly 8

Important TNF Inhibitor Safety Considerations

• Screen for latent tuberculosis before initiating therapy and monitor during treatment 7, 8
• Increased risk of serious infections including TB reactivation, invasive fungal infections, and opportunistic infections 7, 8
• Increased risk of lymphoma and other malignancies, particularly hepatosplenic T-cell lymphoma in young males receiving concomitant azathioprine or 6-mercaptopurine 7, 8
• Discontinue TNF inhibitor if patient develops serious infection or sepsis 7, 8

Treatments to AVOID

Systemic glucocorticoids are strongly recommended AGAINST in AS. 1, 2 They have not demonstrated efficacy and carry significant adverse effects 1.

Surgical Management

For patients with advanced hip arthritis, total hip arthroplasty is strongly recommended. 1, 2

Monitoring and Treatment Goals

• Monitor disease activity using clinical signs, symptoms, and acute phase reactants 2, 4
• The primary treatment goal should be clinical remission or inactive disease, agreed upon between patient and rheumatologist 2
• Adjust treatment if therapeutic goals are not met 2

When to Refer to Rheumatology

Refer patients with suspected AS who have back pain starting before age 45, lasting more than 3 months, plus at least 4 of the following: back pain starting before age 35, nocturnal pain, buttock pain, improvement with movement or within 2 days of NSAID use, first-degree relative with spondyloarthritis, or current/past arthritis, enthesitis, or psoriasis 2.

Common Pitfalls

• Do not exclude AS based solely on negative HLA-B27, normal CRP, or normal ESR 2
• Do not use analgesics (acetaminophen, opioids) as first-line therapy; reserve these only for residual pain after failure of NSAIDs and TNF inhibitors 2
• Do not use sulfasalazine for axial disease (it may help peripheral arthritis but lacks efficacy for spinal symptoms) 9
• Early diagnosis is crucial, as there is typically a 5-7 year delay between symptom onset and diagnosis 2