Lost medicines: a longer view of the pharmaceutical industry with the potential to reinvigorate discovery.

It is widely understood that the 1962 Kefauver-Harris Amendment to the Food, Drug and Cosmetics Act ushered in the modern regulation of medicines requiring a combination of safety and efficacy. However, fewer appreciate the amendment was applied retroactively to virtually all medicines sold in the USA. For various reasons, many medicines faded into history. Here, we identify and analyze >1600 medicines (including over-the-counter drugs) and their innovators prior to the enactment of Kefauver-Harris. We report 880 of these past medicines are no longer accessible. This project also reveals new insight into the pharmaceutical enterprise, which reveals an industry already mature and beginning to retract before enactment of the legislation. Beyond its historical implications, the recollection of these medicines could offer potential starting points for the future development of much-needed drugs.