WASHINGTON -- Despite being plagued by major safety problems in recent years, drug makers have failed to initiate more than 70 percent of promised studies on drugs already approved for the market, according to the latest numbers from the Food and Drug Administration.

A report posted by the FDA shows that 899 -- or 71 percent -- of the 1,259 post-market studies committed to by drug makers had not been started as of Sept. 30, 2006. That's an increase of 5 percent over last year, when the FDA reported that 65 percent of the promised 1,231 studies were still pending, according to Bloomberg News.
The report found that only 185 -- or 15 percent -- of studies were ongoing, 31 were delayed, and 144 were submitted.

Currently, some drugs are approved with outstanding safety concerns on the promise that the drug's maker will perform post-market safety studies to determine if the medication causes side effects over a period of time. But the FDA has no authority under law to require those studies be performed.