U-50488

U-50488 is a drug which acts as a highly selective κ-opioid agonist, but without any μ-opioid antagonist effects. It has analgesic, diuretic and antitussive effects, and reverses the memory impairment produced by anticholinergic drugs. U-50488 was one of the first selective kappa agonists invented and research on its derivatives has led to the development of a large family of related compounds.