Report on a Long-Term Tolerability Study of Up to Two Years with Diclofenac Sodium (Voltaren)

This paper reports on a non-comparative multicentre trial designed to assess the usefulness of the non-steroid anti-inflammatory agent diclofenac sodium (Voltaren®) in the long-term treatment of rheumatic diseases. Of the 268 patients entering the trial, 84 had rheumatoid arthritis, 168 osteoarthrosis, and 16 other arthritic conditions. The dosage of the trial medication was flexible: depending on the severity of the disease, it ranged from 50 to 150 mg daily. At the time of reporting, 152 patients had completed 12 months and 11 patients had completed 24 months of treatment; 28 % were still continuing treatment in the trial. 24 % of the patients were withdrawn from the trial because, in the centre at which they were participating, the trial had reached its planned end. In another 24%, the treatment was discontinued because it had exerted such an excellent effect that it was no longer required; in 9% of cases, on the other hand, the patients withdrew from the trial because the therapeutic effect had proved inadequate. A further 10% were withdrawn for other reasons not related to the trial drug. Unwanted effects–the majority of them referable to the gastro-intestinal tract–were responsible for discontinuation of the treatment in 6% of the patients. Improvement in the status of the arthritic condition was recorded in one-half of the patients with rheumatoid arthritis and in two-thirds of those with osteoarthrosis. This improvement occurred primarily during the first three months of treatment and was maintained thereafter. Unwanted effects, the occurrence of which was almost exclusively confined to the first 3-6 months of treatment, were reported in one-quarter of the patients; they did not appear to be dose-related. The drug's laboratory tolerability was satisfactory. On the basis of these results it can be concluded that, in the long-term treatment of rheumatic diseases, diclofenac sodium is an effective and well-tolerated non-steroid agent. There was no evidence that tolerance to the drug developed or that unwanted effects increased in frequency or differed in nature with time.