Clinical trials for the safety of drugs on the market

GlaxoSmithKline Plc's diabetes drug Avandia is at the center of controversy. During recent clinical trials of the drug, safety issues have arisen. This brought up the issue looking at whether or not it was ethical to look at the risks of a drug already in use.

The Institute of Medicine concluded:
Clinical trials aimed at pinpointing emerging safety problems with drugs already on the market should only be conducted when other, less invasive research is not possible.

Read the full article here. What do you think of this statement?