Abstract: Previous studies (Xiao et al., 2001) have identified two metabolites of methadone, EMDP (2-ethyl-5-methyl-3,3-diphenyl-1-pyrroline) and EDDP (2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine), which are considered to be inactive at opiate receptors, as relatively potent noncompetitive channel blockers of ?3?4 nAChRs. We have now evaluated these compounds in rats and mice in preclinical behavioral models predictive of potential anxiolytic and antidepressant efficacy. We found that EMDP, but not EDDP, displayed robust effects predictive of anxiolytic and antidepressant efficacy without significant effects on locomotor activity. Moreover, EMDP at behaviorally active doses, unlike mecamylamine, did not produce eyelid ptosis, suggesting it may produce fewer autonomic side effects than mecamylamine. Thus, the methadone metabolite EMDP may represent a novel therapeutic avenue for the treatment of some affective disorders.

Abstract: Previous studies (Xiao et al., 2001) have identified two metabolites of methadone, EMDP (2-ethyl-5-methyl-3,3-diphenyl-1-pyrroline) and EDDP (2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine), which are considered to be inactive at opiate receptors, as relatively potent noncompetitive channel blockers of ?3?4 nAChRs. We have now evaluated these compounds in rats and mice in preclinical behavioral models predictive of potential anxiolytic and antidepressant efficacy. We found that EMDP, but not EDDP, displayed robust effects predictive of anxiolytic and antidepressant efficacy without significant effects on locomotor activity. Moreover, EMDP at behaviorally active doses, unlike mecamylamine, did not produce eyelid ptosis, suggesting it may produce fewer autonomic side effects than mecamylamine. Thus, the methadone metabolite EMDP may represent a novel therapeutic avenue for the treatment of some affective disorders.

Abstract: Disclosed are methods of treating anxiety or depression, comprising administering to a subject in need thereof a therapeutically effective amount of a compound selected from the group consisting of 2-ethyl-5-methyl-3,3-diphenyl-1-pyrroline (EMDP), 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP), and pharmaceutically acceptable salts thereof.

Abstract: Disclosed are methods of treating anxiety or depression, comprising administering to a subject in need thereof a therapeutically effective amount of a compound selected from the group consisting of 2-ethyl-5-methyl-3,3-diphenyl-1-pyrroline (EMDP), 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP), and pharmaceutically acceptable salts thereof.