Arylacetamide κ opioid receptor agonists with reduced cytochrome P450 2D6 inhibitory activity

Some K opioid receptor agonists of the arylacetamide class, for example, ICI 199441 (1), were found to strongly inhibit the activity of cytochrome P450 2D6 (CYP2D6) (1: CYP2D6 IC50 = 26 nM). Certain analogs bearing a substituted sulfonylamino group, for example, 13, were discovered to have significantly reduced CYP2D6 inhibitory activity (13: CYP2D6 IC50 > 10 mu M) while displaying high affinity toward the cloned human K opioid receptor, good kappa/delta and kappa/mu selectivity, and potent in vitro and in vivo agonist activity. (c) 2005 Elsevier Ltd. All rights reserved.