Quadazocine (WIN-44,441) is an opioid antagonist of the benzomorphan family which is used in scientific research. It acts as a silent antagonist at all three of the major opioid receptors—μ, κ, and δ, but with a significant preference in affinity for the μ receptor and the κ2 subtype. As such, it has been touted as a `κ2-selective` antag.....