REL-1017 (esmethadone) Demonstrates No Withdrawal Effects or Evidence of Physical Dependence in a Rat Study

Gauvin D, Henningfield JE, Fant RV, Buchhalter AR, Ashworth J, Caron J, Pappagallo M, Bifari F, Folli F, Manfredi PL

REL-1017 (esmethadone) is a novel NMDA channel blocker in development for major depressive disorder (MDD). REL-1017 has twenty-fold lower affinity than levomethadone at the mu-opioid receptor. According to a 2019 DEA statement, “The d-isomer lacks significant respiratory depressant action and addiction liability but possesses antitussive activity.” We assessed the potential of REL-1017 to produce physical dependence and signs of withdrawal. The active comparators were morphine and ketamine.

Presented at the College on Problems of Drug Dependence 83rd Annual Scientific Virtual Meeting, June 21–24, 2021