What is the role of topical Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) in managing osteoarthritis?

Role of Topical NSAIDs in Managing Osteoarthritis

Topical NSAIDs are strongly recommended as first-line pharmacological treatment for knee osteoarthritis and conditionally recommended for hand osteoarthritis due to their favorable safety profile compared to oral analgesics while providing effective pain relief. 1

Efficacy and Indications

• Topical NSAIDs should be considered prior to oral NSAIDs for accessible joints, particularly for knee OA (strong recommendation) and hand OA (conditional recommendation) 1
• Topical NSAIDs provide similar pain relief as oral NSAIDs but with fewer systemic side effects, making them particularly valuable for patients with risk factors for NSAID-related complications 1, 2
• Topical diclofenac is FDA-approved specifically for the treatment of pain associated with osteoarthritis of the knee 3
• Topical NSAIDs are not recommended for hip OA due to the depth of the joint beneath the skin surface, which makes topical application unlikely to provide benefit 1

Safety Profile

• Topical NSAIDs have a superior safety profile compared to oral NSAIDs, with fewer gastrointestinal, cardiovascular, and renal adverse events 1, 4
• Topical NSAIDs are particularly beneficial for elderly patients (≥75 years) and those with comorbidities or increased risk of systemic NSAID-related complications 4
• The main side effects of topical NSAIDs are limited to local application site reactions, with systemic adverse events being rare 5

Treatment Algorithm for Osteoarthritis

1. First-line approach: Begin with core treatments for all patients:

   • Regular exercise programs (walking, strengthening, aquatic) 6
   • Weight loss if overweight or obese 6
   • Self-management education 6

2. First-line pharmacological treatment:

   • For knee OA: Topical NSAIDs (strong recommendation) 1
   • For hand OA: Topical NSAIDs (conditional recommendation) 1
   • For hip OA: Consider oral NSAIDs as topical preparations are unlikely to be effective 1

3. If inadequate response to topical NSAIDs:

   • Progress to oral NSAIDs at the lowest effective dose for the shortest possible duration 1
   • Consider paracetamol (acetaminophen) if NSAIDs are contraindicated 1

4. For persistent symptoms or flares:

   • Consider intra-articular corticosteroid injections for knee and hip OA (strong recommendation) and hand OA (conditional recommendation) 1

Practical Considerations

• When selecting a topical NSAID, consider formulation properties as there is heterogeneity among products regarding absorption and bioavailability 4
• Diclofenac formulations have shown good efficacy with evidence of accumulation in synovial tissues 4
• For patients with multiple affected joints, systemic pharmacological treatment may be more practical than topical NSAIDs 1
• Topical NSAIDs should be applied to clean, dry skin and patients should wash hands after application unless the hands are the treated joint 2
• Practical considerations such as frequent hand washing may limit the use of topical NSAIDs for hand OA 1

Comparative Efficacy

• Multiple head-to-head trials have demonstrated that topical NSAIDs provide at least equivalent analgesia, improved physical function, and reduced stiffness compared to oral NSAIDs in osteoarthritis 2
• Studies comparing diclofenac gel with ketoprofen gel showed equal efficacy between these topical NSAID formulations 7
• Topical capsaicin is conditionally recommended for knee OA but conditionally recommended against for hand OA due to small effect sizes and risk of eye contamination 1

By following this evidence-based approach to incorporating topical NSAIDs into osteoarthritis management, clinicians can provide effective pain relief while minimizing systemic adverse effects, particularly in vulnerable populations.