[The need for 'postmarketing surveillance'].

Postmarketing surveillance of medicines includes two activities: pharmacovigilance and pharmaco-epidemiology. Despite the importance of postmarketing surveillance, too few surveillance studies are performed. The studies carried out by the pharmaceutical industry predominantly consist of 'seeding trials': offering prescribing physicians financial rewards if they prescribe a particular product, thus trying to change the prescription habits. The results of such trials are scientifically worthless. These activities cast a shadow on sincere postmarketing surveillance. A recent nationwide cohort study by the Inspectorate for Health Care on mortality in users of ibopamine demonstrates that Dutch medical doctors and pharmacists are very co-operative if further studying of a particular adverse reaction is warranted.