A long-term, open-label study to confirm the safety of topical diclofenac solution containing dimethyl sulfoxide in the treatment of the osteoarthritic knee.

To assess the long-term safety of a topical solution of diclofenac sodium in a vehicle containing dimethyl sulfoxide (TDiclo), subjects with radiologically confirmed, symptomatic osteoarthritis of the knee(s) applied the clinical dose of TDiclo (40 drops, four times daily) to each painful knee for up to 52 weeks. Safety assessment included adverse events, skin irritation scores of the treated knee(s), ocular examinations, and routine laboratory tests. There were 793 subjects (mean age, 62.5 years) who applied TDiclo to one or both (72%) knees for an average of 204 days, including 463 subjects for 6 months and 144 for 1 year. The most frequent adverse events were at the application site with no increase in incidence with prolonged exposure: dry skin (25.3%), contact dermatitis without vesicles (13.0%) or with vesicles (9.5%). Skin irritation score was 0 (normal) in 61.0% of subjects, 0.5 (dryness or flaking) in 23.9%, 1 or 2 (erythema without or with induration) in 6.9%, and 3 or 4 (erythema with induration and vesicles/bullae) in 8.2%. Subject dropouts included 114 (14.4%) with an application site skin adverse event. Individual subject laboratory test shift to abnormal occurred for hemoglobin (3.2%), aspartate aminotransferase (6.4%), alanine aminotransferase (7.3%), and creatinine (4.2%), but few shifts (less than 0.3% per variable) were clinically significant. No increased risk of cardiovascular or cataract events was noted. This long-term study of TDiclo revealed a safety profile comparable to that shown in multiple, shorter, well-controlled, double-blind trials with the predominant adverse effect noted being an application site reaction.

Efficacy and safety of a topical diclofenac solution (pennsaid) in the treatment of primary osteoarthritis of the knee: a randomized, double-blind, vehicle-controlled clinical trial.

BACKGROUND: Oral nonsteroidal anti-inflammatory drugs (NSAIDs) are commonly used to relieve the symptoms of osteoarthritis (OA) but can produce harmful systemic effects and end-organ damage. A topical NSAID formulation may provide symptom relief with fewer adverse effects. A new topical diclofenac sodium solution-containing the absorption enhancer dimethyl sulfoxide-was evaluated for the relief of the symptoms of primary OA of the knee. METHODS: A total of 326 patients met entry criteria (including abnormal radiographic findings and flare of pain) and were randomized to receive 40 drops of topical diclofenac solution or a vehicle-control solution, 4 times daily, for 12 weeks. We evaluated 3 primary outcome measures, the Western Ontario McMaster Universities LK3.1 OA Index (WOMAC) pain and physical function subscales and a patient global assessment, and 2 other measures, stiffness and pain on walking, at baseline and after final application. We assessed safety by evaluation of adverse events, vital signs, and irritation at the application site. RESULTS: Topical diclofenac solution was significantly more effective than the vehicle-control solution for all outcome measures; pain, P = .001; physical function, P = .002; patient global assessment, P = .003; stiffness, P = .005; and pain on walking, P = .004. Among patients receiving topical diclofenac, self-limiting minor skin irritation occurred in 68 (41.5%) of 164 patients, including dryness in 60 (36.6%), rash in 18 (11.0%), and paresthesia, pruritus, and vesiculobullous rash in 1 (0.6%) each. There was no significant difference between groups in NSAID-related gastrointestinal tract complaints or in dropouts due to study-related adverse effects. CONCLUSION: Topical diclofenac is effective in the treatment of the symptoms of primary OA of the knee, with only minor local irritation and no significant systemic adverse events.

Equivalence study of a topical diclofenac solution (pennsaid) compared with oral diclofenac in symptomatic treatment of osteoarthritis of the knee: a randomized controlled trial.

OBJECTIVE: . To compare the safety and efficacy of a topical diclofenac solution versus oral diclofenac in relieving the symptoms of primary osteoarthritis (OA) of the knee, in a randomized, double-blind, double-dummy equivalence trial. METHODS: A total of 622 men and women with radiological evidence of primary knee OA and mild to severe symptoms were randomly assigned to treatment with a topical diclofenac solution plus placebo oral capsules, or placebo topical solution plus oral diclofenac (50 mg) capsules. Patients applied 50 drops of study solution and took 1 study capsule 3 times daily for 12 weeks. Efficacy variables were pain and physical function, measured by the Western Ontario and McMaster Universities (WOMAC) VA 3.1 OA Index, and patient global assessment (PGA). Equivalence in the per-protocol group was based on previously defined ranges of clinically significant difference. Safety was assessed by evaluation of adverse events, vital signs, and laboratory data. RESULTS: The difference in mean (95% CI) change scores (final minus baseline) between treatments was 13.3 mm (-8.6 to 35.2) for pain (total scale 500 mm), 71.0 mm (-2.4 to 144.5) for physical function (total scale 1700 mm), and 4.3 mm (-1.2 to 9.8) for PGA (total scale 100 mm). The CI for each efficacy variable fell within the predefined equivalence ranges (pain, +/- 75 mm; physical function, +/- 255 mm; PGA, +/- 20 mm), indicating that no clinically relevant difference was found between the 2 treatment arms. Safety analyses of patients applying topical diclofenac solution revealed some minor skin irritation at the application site--mostly skin dryness in 83/311 (27%) patients--but a significantly reduced incidence, relative to oral diclofenac, of total and severe gastrointestinal (GI) adverse events, including dyspepsia, abdominal pain, diarrhea, and nausea. The number of patients developing abnormal liver function tests (including clinically significant elevation), hemoglobin, and creatinine clearance was significantly higher in the oral diclofenac group. CONCLUSION: Application of this topical diclofenac solution to the knee of patients with OA produced relief of symptoms equivalent to oral diclofenac, with minor local skin irritation, but significantly reduced incidence of diclofenac-related GI complaints and abnormal laboratory values.

Effect of a topical diclofenac solution for relieving symptoms of primary osteoarthritis of the knee: a randomized controlled trial.

BACKGROUND: Treatment of osteoarthritis with oral NSAID therapy provides pain relief but carries a substantial risk of adverse effects. Topical NSAID therapy offers an alternative to oral treatment, with the potential for a reduced risk of side effects. The objective of this trial was to assess the safety and efficacy of a topical diclofenac solution in relieving the symptoms of primary osteoarthritis of the knee. METHODS: We identified 248 men and women from southern Ontario with primary osteoarthritis of the knee and at least moderate pain. The patients were randomly assigned to apply 1 of 3 solutions to their painful knee for 4 weeks: a topical diclofenac solution (1.5% wt/wt diclofenac sodium in a carrier containing dimethyl sulfoxide [DMSO]); a vehicle-control solution (the carrier containing DMSO but no diclofenac); and a placebo solution (a modified carrier with a token amount of DMSO for blinding purposes but no diclofenac). The primary efficacy end point was pain relief, measured by the Western Ontario and McMaster Universities (WOMAC) LK3.0 Osteoarthritis Index pain subscale. Secondary end points were improved physical function and reduced stiffness (measured by the WOMAC subscales), reduced pain on walking and patient global assessment (PGA). Safety was evaluated with clinical and laboratory assessments. RESULTS: In the intent-to-treat group the mean change (and 95% confidence interval [CI]) in pain score from baseline to final assessment was significantly greater for the patients who applied the topical diclofenac solution (-3.9 [- 4.8 to -2.9]) than for those who applied the vehicle-control solution (-2.5 [- 3.3 to -1.7]; p = 0.023) or the placebo solution (-2.5 [-3.3 to -1.7]; p = 0.016). For the secondary variables the topical diclofenac solution also revealed superiority to the vehicle-control and placebo solutions, leading to mean changes (and 95% CIs) of -11.6 (-14.7 to -8.4; p = 0.002 and 0.014, respectively) in physical function, -1.5 (-1.9 to -1.1; p = 0.015 and 0.002, respectively) in stiffness and -0.8 (-1.1 to -0.6; p = 0.003 and 0.015, respectively) in pain on walking. The PGA scores were significantly better for the patients who applied the topical diclofenac solution than for those who applied the other 2 solutions (p = 0.039 and 0.025, respectively). The topical diclofenac solution caused some skin irritation, mostly minor local skin dryness, in 30 (36%) of the 84 patients, but this led to discontinuation of treatment in only 5 (6%) of the cases. The incidence of gastrointestinal events did not differ between the treatment groups. No serious gastrointestinal or renal adverse events were reported or detected by means of laboratory testing. INTERPRETATION: This topical diclofenac solution can provide safe, site-specific treatment for osteoarthritic pain, with only minor local skin irritation and minimal systemic side effects.