Tolerability of topical diclofenac sodium 1% gel for osteoarthritis in seniors and patients with comorbidities

Background: Nonsteroidal anti-inflammatory drugs (NSAIDs) are associated with a dose-related risk of cardiovascular, renal, and gastrointestinal adverse events (AEs). Topical NSAIDs produce lower systemic NSAID exposure compared with oral NSAIDs, offering potential benefits.

Objective: To evaluate the safety of topical diclofenac sodium 1% gel (DSG) for knee and hand osteoarthritis (OA) in older and younger patients and in patients with versus without comorbid hypertension, type 2 diabetes, or cerebrovascular or cardiovascular disease.

Methods: Post hoc analysis of pooled data from 5 randomized, double-blind, placebo-controlled trials involving 1426 patients (aged ≥35 years) with mild to moderate OA of the knee and 783 patients (aged ≥40 years) with mild to moderate OA of the hand. Patients applied 4 g of DSG or vehicle to affected knees QID for 12 weeks or 2 g of DSG or vehicle to affected hands QID for 8 weeks.

Results: In patients with knee OA, the percentage with ≥1 adverse event was similar in patients aged <65 years (56.6%) versus ≥65 years (55.8%) and was similar in patients with versus without comorbid hypertension (53.4% vs 59.0%, respectively), type 2 diabetes mellitus (50.0% vs 57.2%), or cerebrovascular or cardiovascular disease (53.8% vs 56.5%). In patients with hand OA, the percentage with ≥1 AE was similar in patients aged ≥65 years (42.7%) versus <65 years (39.1%) and was similar in patients with versus without hypertension (39.6% vs 41.7%, respectively), lower in patients with versus without type 2 diabetes mellitus (28.0% vs 41.6%), and higher in patients with versus without cerebrovascular or cardiovascular disease (48.5% vs 39.2%). Gastrointestinal, cardiovascular, and renal AEs were rare and did not differ according to age or comorbidity. Application site reactions were the primary cause for the greater frequency of AEs with DSG versus vehicle.

Conclusion: The similar and low rates of AEs in DSG-treated patients aged ≥65 years and <65 years and in those with and without comorbid hypertension, type 2 diabetes, or cerebrovascular or cardiovascular disease suggest that DSG treatment is generally well tolerated.