According to this Reuters story, Senator Grassley now is asking "for Congress to give the Food and Drug Administration more power to review drugs after they are approved for the public, citing a government report that found lingering safety concerns at the agency." More from the article:
The FDA sometimes approves products under the condition that companies later provide more data, but it lacks the authority to require such studies in most cases. The GAO said longer trials after approval could "answer safety questions about risks associated with the longer-term use of drugs."
Thanks to Deb for the pointer!