Enadoline (Free Base) is a kappa-opioid receptor agonist; PD 129290 (CAM 570; CI 977) is the S,S(-)-enantiomer; PD 129289 (CAM 569) is the corresponding R,R(+)-enantiomer. In human studies, it produced visual distortions and feelings of dissociation, reminiscent of the effects of salvinorin A. It was studied as a potential analgesic, but abandoned because of the dose-limiting effects of dysphoria, which could be expected from a κ-opioid agonist. There was mention of its potential in treating comatose head injury or stroke victims, where that type of side effect would be immaterial.
