Fentanyl, a narcotic analgesic, is the active ingredient contained in adhesive patch form for use by
chronic pain and cancer patients that are opioid tolerant. Long acting release of up to 3 days in a single patch. Duragesic is the brand name of
the original patch system which is now
available in several generic forms and differing patch systems. Patches come in 5 different dosages that deliver from 12.5 micrograms/hour up to 100 micrograms/hour in situ through the skin into the bloodstream.