Painkiller Patch Fentanyl May Have Killed 3,500 People, Warns FDA

The popular patch version of the pain killer fentanyl is suspected in more than 3,500 deaths, and the FDA has issued a new warning about its use.

The fentanyl patch is designed for patients with chronic pain, especially those who have trouble swallowing pills. The patch steadily releases the drug over the course of three days.

Many safety advocates have criticized the FDA's most recent warning as insufficient, noting that fentanyl has killed far more people than the 932 deaths attributed to Vioxx, which the FDA has withdrawn from the market

"I think there is more that needs to be done, or else we're just going to see this [warning] happen again another two years from now," said Michael Cohen, president of the Institute for Safe Medication Practices. "The deaths are going to continue."