Adverse reactions to indoprofen: a survey based on a total of 6764 patients

Safety data on indoprofen are presented, deriving from three sources: the first was a phase 4 multicentre clinical study based on 4042 patients suffering from osteoarthritis and treated with 400-800 mg daily by mouth for about 4 weeks; the second was a survey based on a heterogeneous series of 2722 subjects belonging to phase 1, 2 and 3 investigations, and treated with 200 to 1200 mg daily by the oral and/or parenteral route for from 1 to more than 180 days; the third was a safety laboratory study conducted in 472 patients, most of whom had participated in the first study, while the remainder were included in the second. Adverse events of any type occurred in 22% of patients in the first study and in 13% in the second, but treatment had to be withdrawn for drug-related reasons in less than 5% in both. Potentially life-threatening events were rare, overall including 16 instances of clinically overt gastro-intestinal bleeding and 2 anaphylactic reactions. Unfavourable laboratory changes, i.e. shifting from normal to abnormal values, were recorded in about 10% of the series studied. The adverse reaction profile of indoprofen was similar to that of most NSAIDs, with gastro-intestinal troubles prevailing over the other events, a distribution which, however, was clear-cut only with oral indoprofen. Tolerability problems appeared to be dose-related up to some point between 400 and 600 mg daily plateauing thereafter, and were less frequent following parenteral than following oral administration.