Why were the Fentanyl patches recalled twice than put on the market?
Duragesic patches were recalled because there were negligible tears in the patches, thus releasing more fentanyl than should have been released per hour. These patches were taken off the market, the pharmaceutical companies (including the ones that made generic patches) rectified the problem and then the patches were on the market again.
Why is the Fentanyl patch used for drug withdrawls?
Because it will keep you from withdrawling without feeling "High" from the opiates .