TEMPORAL TRENDS IN SPONTANEOUS REPORTING OF UNLABELED ADVERSE DRUG-REACTIONS

Aims Trends in spontaneous reporting during the first years on the mar ket were analyzed from a sample of selected drugs, with special attent ion to unlabelled effects. Methods Ten drugs were selected giving rise to approximately 100 spontaneous reports each during the first 4 year s of marketing. Case reports were identified from the national pharmac ovigilance database. A bibliographical score assigned at the time of r eporting was used to identify unlabelled effects. Results were express ed as reporting rates. Results The average reporting rate peaked durin g the first year of marketing (54.6 per million treatment-months; s.d. :62.8), then progressively decreased during the following years. Unlab elled effects represented 63% of all the spontaneous reports during th e first year. Conclusions Unlabelled adverse effects represent a high proportion of spontaneous reports during the early years of marketing.