Although computed statistics may vary from study to study, there is general consensus that the incorrect use of medicine costs billions of dollars a year and harm millions of people. There are estimates that as high as 20% of all dosages administered in hospitals contain errors; although most of them concern quantity errors (1mg vs 10mg) rather than patients being given incorrect medication.
Both the University Health System (U.H.S.) and F.D.A.'s MedWatch offer users the opportunity to directly report negative reactions to drugs, fostering accountability in healthcare.
By contrast, an ergonomist would dissect the problem and try to find out contributing factors and key players (e.g. pharmacists, doctors, patients) who they could study the tasks of (e.g. sorting, prescribing, & consuming miedications) in order to arrive at an ergonomically sound solution. In the UHS, the solution was to improve training.