Initial Treatment for Ankylosing Spondylitis
NSAIDs are strongly recommended as first-line drug treatment for patients with ankylosing spondylitis with pain and stiffness. 1 This recommendation is consistent across all major guidelines and is supported by high-quality evidence demonstrating their efficacy in reducing pain, improving function, and decreasing disease activity.
Treatment Algorithm
First-Line Treatment:
- NSAIDs
- Should be used as continuous treatment for patients with persistently active, symptomatic disease 1
- All NSAIDs have similar efficacy, with no single NSAID demonstrating clear superiority 2
- Consider cardiovascular, gastrointestinal, and renal risks when prescribing 1
- For patients with increased gastrointestinal risk, use either:
- Non-selective NSAIDs plus a gastroprotective agent
- A selective COX-2 inhibitor 1
Non-Pharmacological Treatment (to be used alongside NSAIDs):
- Patient education about the disease
- Regular exercise program
- Physical therapy with supervised exercises (more effective than home exercises) 1
- Consider patient associations and self-help groups 1
For Patients with Inadequate Response to NSAIDs:
- TNF inhibitors are strongly recommended for patients with persistently high disease activity despite NSAID treatment 1
- No evidence supports the obligatory use of DMARDs before or concomitant with TNF inhibitor therapy in patients with axial disease 1
For Peripheral Arthritis:
- Consider sulfasalazine for patients with peripheral joint involvement 1
- NSAIDs remain the first-line treatment even for these patients
Evidence Quality and Considerations
The recommendation for NSAIDs as first-line therapy is supported by high-quality evidence showing that NSAIDs improve spinal pain, peripheral joint pain, and function over short time periods. Studies demonstrate that NSAIDs can reduce pain severity compared to placebo with mean differences ranging from -17.49 to -25.99 points on a 100mm visual analog scale 2.
The 2019 ACR/SAA/SPARTAN guidelines strongly recommend NSAIDs over no treatment for active AS 1. Similarly, the ASAS/EULAR recommendations consistently position NSAIDs as the cornerstone of initial pharmacological management 1.
Important Considerations and Caveats
- Continuous vs. On-demand Use: Continuous NSAID therapy may be superior in preventing new bone formation compared to on-demand use 1
- Safety Monitoring: Regular monitoring for adverse effects is essential, particularly:
- Gastrointestinal effects (especially with diclofenac and naproxen) 2
- Cardiovascular risks
- Renal function
- Treatment Response Assessment: If a patient doesn't respond adequately to one NSAID, try another NSAID at an appropriate dose before concluding NSAID therapy is ineffective 3
- Extra-articular Manifestations: Be aware of and manage common extra-articular manifestations (psoriasis, uveitis, inflammatory bowel disease) in collaboration with appropriate specialists 1
- Cardiovascular Risk: Patients with AS have an increased cardiovascular risk that should be considered when prescribing NSAIDs 1
Despite the high efficacy of NSAIDs, approximately 20% of patients may still report insufficient pain control, and over 40% may need to change their NSAID due to lack of efficacy 4. For these patients, progression to TNF inhibitor therapy should be considered promptly rather than cycling through multiple NSAIDs with limited benefit.