Topical Diclofenac Sodium 1% Gel Has Favorable Tolerability Profile

National Harbor, Maryland—Patients with knee or hand osteoarthritis (OA) generally tolerated topical diclofenac sodium 1% gel (DSG) and had only mild adverse events (AEs) that did not require additional treatment, according to a pooled analysis of 5 randomized, double-blind, placebo-controlled trials. The results were presented at the AAPM meeting during a poster session titled Safety of Topical Diclofenac Sodium 1% Gel: A Pooled Analysis of Randomized Controlled Trials. DSG is classified as a nonsteroidal antiinflammatory drug (NSAID) intended to treat OA patients. NSAIDs carry risks related to gastrointestinal (GI), cardiovascular, renal, and other systemic AEs, although topical NSAIDs carry fewer risks. According to the authors, topical NSAIDs are recommended as first-line therapy in OA patients by the Osteoarthritis Research Society International, the European League Against Rheumatism, and the American Academy of Orthopaedic Surgeons. In this study, the authors examined three 12-week trials involving patients with knee OA and two 8-week trials that included patients with hand OA. The patients with knee OA were ≥35 years of age with mild-to-moderate OA for ≥6 months, according to the American College of Rheumatology (ACR) criteria. They also had pain on movement of ≥50 mm on the 100-mm visual analog scale (VAS) and a pain score of ≥9 on a 0 to 20 scale of the Western Ontario and McMaster Universities Osteoarthritis Index (Likert version). In addition, during the month before screening, they had to have daily treatment with acetaminophen, oral NSAIDs, or cyclooxygenase-2 inhibitors. The patients in the hand OA cohort were ≥40 years of age with mild-to-moderate OA in their dominant hand for ≥12 months before the study began, according to the ACR criteria. They also had to have a nodal enlargement in ≥2 finger joints and used an NSAID or salicylate during ≥1 episode. In the 24 hours before their first treatment, they had to have had pain of ≥40 mm on the VAS, and the pain in their dominant hand had to be ≥20 mm greater compared with their other hand. After a washout period of ≥1 week, all patients were randomly assigned on a 1:1 ratio to either a placebo group or the topical DSG group. The knee OA cohort applied 4 g of the placebo or topical DSG to 1 or 2 knees 4 times per day for 12 weeks, whereas the patients with hand OA applied 2 g of the placebo or topical DSG to both hands 4 times per day for 8 weeks. In the knee OA trials, 1142 patients completed the study (590 took topical DSG and 552 took the placebo), whereas 701 patients with hand OA completed the study (354 took topical DSG and 347 took the placebo). Among the patients with knee OA, the AE rate in the topical DSG group (56.3%) was higher than in the placebo group (48.2%). In addition, 2 patients in the DSG group had a hepatic AE compared with 6 in the placebo group. In each group, ≤1% of patients had renal AEs. There were 3 treatment-related GI AEs in the DSG group and 1 in the placebo group. Total AEs in the hand OA cohort were similar in the placebo (36.3%) and topical DSG (40.8%) groups. Two patients in the topical DSG group and 1 in the placebo group had GI AEs. Two patients in the topical DSG group and 1 in the placebo group had liver enzyme elevations ≤3 times the upper limit of normal. No patient had a treatment-related cardiovascular event, serious AE, or renal AE.