A review of spontaneously reported adverse drug reactions with diclofenac sodium (Voltarol)

The author reviews the worldwide picture of adverse reactions reported with diclofenac during the four-year period ending in December 1977, at which point he estimates that some ten million patients had received treatment with the drug. A total of 447 unwanted effects were reported in 194 patients, the most frequently reported side-effects being gastrointestinal in nature, followed by dermatological and central nervous system effects. Thirteen cases of liver function abnormality were reported, although there was reason to believe that 11 of these were not ascribable to diclofenac. Twenty haematological effects were reported, including two cases of agranulocytosis and two cases of fatal aplastic anaemia; one patient in each of these groups was taking concomitant pyrazolone compounds. Evaluation of adverse reactions reported with diclofenac suggest a profile in which gastrointestinal side-effects predominate; however, the risk of serious side-effects of this nature is slight, and the impression of good tolerability which emerges from this review is confirmed by the findings of comparative clinical trials.