Long-term antiplatelet activity and safety of indobufen in patients with cardiovascular disease. Italian Multicenter Study Group.

An open collaborative study was performed to assess the long-term platelet inhibiting activity, tolerability and safety of indobufen, a new inhibitor of platelet aggregation. The drug was given orally to 151 patients with cardiovascular disease for a period ranging from 6 to 24 months (mean 12.5 months). Extensive clinical examination, laboratory investigations and platelet function studies were carried out before the treatment and at 1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 18, 21 and 24 months. Indobufen, 200 mg b.i.d., exerted a prompt inhibitory effect on platelet adhesiveness and aggregation, normalized circulating platelet aggregates and slightly prolonged bleeding time. Five patients were withdrawn from the study due to the occurrence of drug-related, untoward clinical events. For the remaining patients there were no appreciable changes in standard laboratory tests. Gastrointestinal symptoms, generally minor and transient, were the most common complaints recorded during treatment. Compliance with therapy was excellent, as judged by residual tablet counts and platelet function studies. The data obtained in this study indicate that indobufen, 200 mg b.i.d., is associated with a marked inhibition of platelet function and the treatment is well tolerated and safe. Indobufen therefore may prove to be a useful drug in the management of patients with cardiovascular disease.