DuP 747 hydrochloride is an analgesic with selective kappa-opioid receptor agonist activity. DuP 747 showed less spiradoline-appropriate selection when administered SC, but showed a partial generalized response to spiradoline when administered IP or PO. The 5-hydroxy-desmethoxy metabolite of DuP 747 induced selection of the saline-appropriate lever only. The effects of DuP 747 suggest that its metabolites may play a major role in the similar responses to spiradoline after IP and PO administration.