What is fentanyl? Fentanyl is a synthetic opioid pain reliever, 80 to 100 times more potent than morphine, that is typically used for severe pain treatment and management for patients who are physically tolerant to other opioids. In prescription form, fentanyl is known by brand names such as Duragesic®, Sublimaze® and Actiq®. In its prescribed form, it comes in transdermal […]