It happened during the Toon admin. Why do you think?
Because the liability lawyers in the U.S. have made it impossible for you to determine your own cost to benefit ratio. Most of these drugs deliver lots of benefit to lots of people, but, in rare cases they cause problems.
The U.S. liability lawyers have sold the soccer moms on the idea that risk can equal zero, so when *any* measurable risk shows up, if the drug doesn't solve a life threatening issue, it has to be taken off the market or the company is bankrupted, no matter how small the risk.