Enadoline is a drug which acts as a highly selective κ-opioid

agonist An agonist is a chemical that activates a receptor to produce a biological response. Receptors are cellular proteins whose activation causes the cell to modify what it is currently doing. In contrast, an antagonist blocks the action of the ago ...

. In human studies, it produced visual distortions and feelings of

dissociation Dissociation, in the wide sense of the word, is an act of disuniting or separating a complex object into parts. Dissociation may also refer to: * Dissociation (chemistry), general process in which molecules or ionic compounds (complexes, or salts) ...

, reminiscent of the effects of

salvinorin A Salvinorin A is the main active psychotropic molecule in '' Salvia divinorum''. Salvinorin A is considered a dissociative hallucinogen. It is structurally distinct from other naturally occurring hallucinogens (such as DMT, psilocybin, and ...

. It was studied as a potential

analgesic An analgesic drug, also called simply an analgesic (American English), analgaesic (British English), pain reliever, or painkiller, is any member of the group of drugs used to achieve relief from pain (that is, analgesia or pain management). It ...

, but abandoned because of the dose-limiting effects of

dysphoria Dysphoria (; ) is a profound state of unease or dissatisfaction. It is the semantic opposite of euphoria. In a psychiatric context, dysphoria may accompany depression, anxiety, or agitation. In psychiatry Intense states of distress and unea ...

, which could be expected from a κ-opioid agonist. There was mention of its potential in treating

coma A coma is a deep state of prolonged unconsciousness in which a person cannot be awakened, fails to respond normally to painful stimuli, light, or sound, lacks a normal wake-sleep cycle and does not initiate voluntary actions. Coma patients exhi ...

tose head injury or

stroke A stroke is a medical condition in which poor blood flow to the brain causes cell death. There are two main types of stroke: ischemic, due to lack of blood flow, and hemorrhagic, due to bleeding. Both cause parts of the brain to stop functionin ...

victims, where that type of side effect would be immaterial.

Potency

When enadoline was first reported in 1990, it was "the most potent κ-selective analgesic ever reported ... 25 times more potent than morphine and 17 times more potent than

U-62066 Spiradoline (U-62066) is a drug which acts as a highly selective κ-opioid agonist. It has analgesic, diuretic, and antitussive effects, and produces subjective effects in animals similar to those of ketazocine and alazocine. The main effect in ...

References

Synthetic opioids Dissociative drugs Pyrrolidines Kappa-opioid receptor agonists Tetrahydrofurans Acetamides Benzofuranethanamines Spiro compounds Psychedelic drugs Abandoned drugs {{Psychoactive-stub