U-69,593 is a drug which acts as a potent and selective ú<sub>1</sub>-opioid receptor agonist. In animal studies it has been shown to produce antinociception, anti-inflammation, anxiolysis (at low doses), respiratory depression, and , while having little effect on gastrointestinal motility. It also inhibits the peripheral, though not central secretion of oxytocin and vasopressin in rats.