WIN-7681

WIN-7681 (Allylnorpethidine) is a 4-phenylpiperidine derivative that is related to the opioid analgesic drug pethidine (meperidine).

WIN-7681 is an analogue of pethidine where the N-methyl group has been replaced by allyl. In many other opioid derivatives, placing an allyl substituent on the nitrogen instead of a methyl will reverse the normal opioid effects, to produce μ-opioid antagonists which among other things reverse the respiratory depression caused by opioid agonists such as morphine. This is not true with WIN-7681, as while it does partially reverse the respiratory depression produced by morphine it is actually an active analgesic and has no antagonistic properties when administered alone, so is instead a partial agonist.