Skip to main content

Clinical Studies Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared with rates in the clinical trials of another drug and may not reflect the rates observed in practice.

During clinical development, 913 patients were exposed to Voltaren® Gel (diclofenac sodium gel) in randomized, double-blind, multicenter, vehicle-controlled, parallel-group studies in osteoarthritis of the superficial joints of the extremities. Of these, 513 patients received Voltaren® Gel (diclofenac sodium gel) for osteoarthritis of the knee and 400 were treated for osteoarthritis of the hand. Additionally, 583 patients were exposed to Voltaren® Gel (diclofenac sodium gel) in an uncontrolled, open-label, long-term safety trial in osteoarthritis of the knee. Of these, 355 patients were treated for osteoarthritis of 1 knee and 228 were treated for osteoarthritis of both knees. Duration of exposure ranged from 8 to 12 weeks for the placebo-controlled studies, and up to 12 months for the open-label safety trial.

Short-Term Placebo-Controlled Trials

Adverse reactions observed in at least 1% of patients treated with Voltaren® Gel (diclofenac sodium gel) :

Non-serious adverse reactions that were reported during the short-term placebo-controlled studies comparing Voltaren® Gel (diclofenac sodium gel) and placebo (vehicle gel) over study periods of 8 to 12 weeks (16 g per day), were application site reactions. These were the only adverse reactions that occurred in > 1% of treated patients with a greater frequency in the Voltaren® Gel (diclofenac sodium gel) group (7%) than the placebo group (2%).

Table 1 lists the types of application site reactions reported. Application site dermatitis was the most frequent type of application site reaction and was reported by 4% of patients treated with Voltaren® Gel (diclofenac sodium gel) , compared to 1% of placebo patients.

Table 1 : Non-serious Application Site Adverse Reaction ( ≥ 1% Volteren® Gel Patients)- Short-term Controlled Trials

Adverse Reaction† Voltaren® Gel
N =913
Placebo (vehicle)
X = 876
N (%) N (%)
Anyapplication site reaction 62 (7) 19 (2)
Application site dermatitis 32 (4) 6 ( < 1)
Application site pruritus 7{ < 1) 1 ( < 1)
Application site erythema 6 ( < 1) 3 ( < 1)
Application site paresthesia 5 ( < 1) 3 ( < 1)
Application site dryness 4 ( < 1) 3 ( < 1)
Application site vesicles 3 ( < 1) 0
Application site irritation 2 ( < 1) 0
Application site papules 1 ( < 1) 0
Preferred Term according to MedDRA 9.1

In the placebo-controlled trials, the discontinuation rate due to adverse reactions was 5% for patients treated with Voltaren® Gel (diclofenac sodium gel) , and 3% for patients in the placebo group. Application site reactions, including application site dermatitis, were the most frequent reason for treatment discontinuation.

Long-term Open-label Safety Trial

In the open-label, long-term safety study, distribution of adverse reactions was similar to that in the placebo-controlled studies. In this study, where patients were treated for up to 1 year with Voltaren® Gel (diclofenac sodium gel) up to 32 g per day, application site dermatitis was observed in 11% of patients. Adverse reactions that led to the discontinuation of the study drug were experienced in 12% of patients. The most common adverse reaction that led to discontinuation of the study was application site dermatitis, which was experienced by 6% of patients.