While several minor developments occurred between 1938 and 1962, the next significant milestone in drug regulation was in 1962. Once again, a tragedy caused by drugs motivated the American government to strengthen the FDA. Thalidomide, marketed as a sleeping pill and a treatment for morning sickness, had an unexpected side effect that resulted in the birth of thousands of malformed babies across Europe. Thankfully, FDA Medical Officer Frances Kelsey had blocked thalidomide from being sold on American markets. Kelsey’s decision to bar thalidomide garnered public support and interest for stronger drug regulation. Congress took advantage of the political momentum to pass the Kefauver-Harris Drug Amendments to the FD&C Act. This legislation required pharmaceutical companies to not only prove safety but also effectiveness of their medicine. Significantly, the Kefauver-Harris Drug Amendments were a foundation for extensive clinical trials of medicines, which, of course, is a cornerstone of modern pharmaceutical development. Throughout the 1960s, government contractors retroactively tested drugs approved between 1938 and 1962 to ensure their effectiveness as well as their safety, further reinforcing the emphasis that the FDA now placed on drug efficacy.[17]
