Novel opioids have been reported to cause psychoactive effects similar to heroin, fentanyl, and other opioids. Novel opioids have also
caused adverse events, including death, as described in the literature. Structurally similar compounds include etonitazene, metonitazene, and isotonitazene. Etonitazene and its analogue synthetic opioids were first synthesized and reported in the literature in the 1950s.
Data suggest that this group of analogues can have potency similar to or greater than fentanyl. Recent in vitro data suggest that N-pyrrolidino etonitazene is similar in potency to etonitazene.
N-Pyrrolidino Etonitazene is not explicitly scheduled in the United States; however, etonitazene and isotonitazene are Schedule I