Since the 1930s a series of tragic adverse drug reactions (ADRs) has placed progressively more attention on the new field of pharmacoepidemiology. The stimulus for the 1938 Food and Drug Act was thc marketing of elixir of sulfanilamide dissolved in diethylene glycol, which resulted in the death of over 100 children. The resulting public outcry led to stricter requirements for drug safety (1). In the early 1 960s the world experienced the notorious thalidomide disaster. Mothers who ingested this mild hypnotic (available mostly in Europe) during the first trimester of their pregnancy had an in creased risk of delivering a child with phocomelia, i.e. one missing one or more limbs or parts of limbs (2). Fortunately the drug had not yet been marketed in the United States. The resulting Kefauver-Harris Amendment to the Food, Drug, and Cosmetic Act strengthened the requirements for testing of safety and added a new premarketing requirement for proof of efficacy. In the latc 1960s and early 1 970s Japan experienced an epidemic of subacute myelo-optic-neuropathy (SMON), later attributed to an antimicrobial drug used for prophylaxis and treatment of traveler's diarrhea�lioquinol (3). During the 1970s practolol was recognized as responsible for an oculomucocutaneous syndrome, but only after one million patient-years of worldwide use (4). In the 1980s ticrynafen, benoxaprofen, and zomepirac were all removed from the US market because of serious ADRs, including death. As these and other problems developed, the potential of pharma coepidemiology for addressing them became more clear. For years,