Kappa agonists

Nalbuphine is a semi-synthetic opioid used commercially as an analgesic under a variety of trade names, including Nubain and Manfine.

Dynorphins (Dyn) are a class of opioid peptides that arise from the precursor protein prodynorphin.

Ketamine, sold under the brand name Ketalar among others, is a medication mainly used for starting and maintaining anesthesia.

Morphine is a pain medication of the opiate type which is found naturally in a number of plants and animals.

Mirtazapine (originally branded Remeron, many generics) is an atypical antidepressant with noradrenergic and specific serotonergic activity.

Levomethorphan (INN, BAN) is an opioid analgesic of the morphinan family that has never been marketed.

Menthol is an organic compound or obtained from corn mint, peppermint, or other mint oils.

Pethidine, also known as meperidine and Demerol, is a synthetic opioid pain medication of the phenylpiperidine class.

Pentazocine is a synthetically-prepared prototypical mixed agonist–antagonist narcotic (opioid analgesic) drug of the benzomorphan class of opioids used to treat moderate to moderately severe pain.

Salvinorin A is the main active psychotropic molecule in Salvia divinorum, a Mexican plant which has a long history of use as an entheogen by indigenous Mazatec shamans.

Butorphanol (AAN, BAN, INN and USAN) is a morphinan-type synthetic opioid analgesic developed by Bristol-Myers.

Levorphanol /lɛvaʊrfɑːnɒl/ (brand name Levo-Dromoran) is an opioid medication used to treat moderate to severe pain.

Nalorphine (INN) (brand names Lethidrone, Nalline), also known as N-allyl-normorphine, is a mixed opioid agonist–antagonist with opioid antagonist and analgesic properties.

Herkinorin is an opioid analgesic that is an analogue of the natural product Salvinorin A.

U-69,593 is a drug which acts as a potent and selective κ1-opioid receptor agonist.

8-Carboxamidocyclazocine (8-CAC) is an opioid analgesic drug related to cyclazocine, invented by medicinal chemist Mark P.

Tonazocine (WIN-42,156) is an opioid analgesic of the benzomorphan family which made it to phase II clinical trials for the treatment of postoperative pain, but development was apparently ceased and ultimately it was never marketed.

Hemorphin-4 is an endogenous opioid peptide of the hemorphin family which possesses antinociceptive properties and is derived from the β-chain of hemoglobin in the bloodstream.

Cyprenorphine (M-285) is an opioid drug.

Dynorphin A is a form of dynorphin and an endogenous opioid peptide with the amino acid sequence: Tyr-Gly-Gly-Phe-Leu-Arg-Arg-Ile-Arg-Pro-Lys-Leu-Lys.

Oxilorphan (INN, USAN) (developmental code name L-BC-2605) is an opioid antagonist of the morphinan family that was never marketed.

Asimadoline (EMD-61753) is a drug which acts as a peripherally selective κ-opioid receptor (KOR) agonist.

Difelikefalin (INN) (developmental code names CR845, FE-202845), also known as D-Phe-D-Phe-D-Leu-D-Lys-[γ-(4-N-piperidinyl)amino carboxylic acid] (as the acetate salt), is an analgesic opioid peptide acting as a peripherally specific, highly selective agonist of the κ-opioid receptor (KOR).

Mianserin (brand names: Depnon (IN), Lantanon (ZA), Lerivon (AR, BE, CZ, PL, RU, SK), Lumin (AU), Norval (UK), Tolvon (AU, HK†, IE†, NZ, SG†), Tolmin (DK); where † indicates discontinued products) is a psychoactive drug of the tetracyclic antidepressant (TeCA) therapeutic family.

Etorphine (M99) is a semi-synthetic opioid possessing an analgesic potency approximately 1,000–3,000 times that of morphine.

Levallorphan (INN, BAN) (brand names Lorfan, Naloxifan, Naloxiphan), also known as levallorphan tartate (USAN), is an opioid modulator of the morphinan family used as an opioid analgesic and opioid antagonist/antidote.

Cyclazocine is a mixed opioid agonist/antagonist related to dezocine, pentazocine and phenazocine.

Ketazocine (INN), also known as ketocyclazocine, is a benzomorphan derivative used in opioid receptor research.

Nalodeine, also known more commonly as N-allylnorcodeine, is an opioid antagonist (specifically, an antagonist of the μ-opioid receptor) that was never marketed but is of notability in having been the first opioid antagonist to have been discovered.

RB-64 or 22-thiocyanatosalvinorin A is a semi-synthetic salvonorin derivative and a κ-opioid receptor (KOR) agonist which is used in scientific research.

U-50488 is a drug which acts as a highly selective κ-opioid agonist, but without any μ-opioid antagonist effects.

Naltriben is a potent and selective antagonist for the delta opioid receptor, which is used in scientific research.

HZ-2 is a drug which acts as a highly selective κ-opioid agonist.

Spiradoline (U-62066) is a drug which acts as a highly selective κ-opioid agonist.

Proxorphan (INN), also known as proxorphan tartate (USAN) (developmental code name BL-5572M), is an opioid analgesic and antitussive drug of the morphinan family that was never marketed.

Diacetylnalorphine (BAN) is an opioid drug described as an analgesic and antidote which was never marketed.

Xorphanol (INN) (developmental code name TR-5379 or TR-5379M), also known as xorphanol mesylate (USAN), is an opioid analgesic of the morphinan family that was never marketed.

Cyclorphan is an opioid analgesic of the morphinan family that was never marketed.

CR665 (H-D-Phe-D-Phe-D-Nle-D-Arg-NH-4-Picolyl), also known by the previous developmental code names FE-200665 and JNJ-38488502, is an all D-amino acid peptide that acts as a peripherally restricted κ-opioid receptor agonist.

Lufuradom (INN) is a drug and benzodiazepine derivative which, unlike other benzodiazepines, is described as an analgesic.

Fedotozine (INN; Jo-1196) is an opioid drug of the arylacetamide series which acts as a peripherally-specific, selective κ1-opioid receptor agonist with preference for the κ1A subtype.

Zenazocine (INN; WIN-42,964) is an opioid analgesic of the benzomorphan family which made it to phase II clinical trials before development was ultimately halted and it was never marketed.

Eluxadoline (INN, USAN) (brand name Viberzi vye-BER-zee; former developmental code name JNJ-27018966) is an orally-active drug approved for the treatment of diarrhea and abdominal pain in individuals with diarrhea-predominant irritable bowel syndrome (IBS-D).

Thienorphine is a very potent, extremely long-acting, orally-active opioid analgesic with mixed agonist–antagonist properties which was developed by the Beijing Institute of Pharmacology and Toxicology as a potential treatment for opioid dependence.

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

Nalmefene (trade name Selincro), originally known as nalmetrene, is an opioid antagonist developed in the early 1970s, used primarily in the management of alcohol dependence.

Phenazocine (brand names Prinadol, Narphen) is an opioid analgesic drug, which is related to pentazocine and has a similar profile of effects.

Norbuprenorphine is a major active metabolite of the opioid modulator buprenorphine.

Tifluadom is a benzodiazepine derivative with an unusual activity profile.

Norketamine, or N-desmethylketamine, is the major active metabolite of ketamine, which is formed mainly by CYP3A4.

Lofentanil is one of the most potent opioid analgesics known and is an analogue of fentanyl, which was developed in 1960.

(–)-18-Methoxycoronaridine (18-MC) is a derivative of ibogaine invented in 1996 by the research team around the pharmacologist Stanley D.

Diprenorphine (brand name Revivon; former developmental code name M5050), also known as diprenorfin, is a non-selective, high-affinity, weak partial agonist of the μ- (MOR), κ- (KOR), and δ-opioid receptor (DOR) (with equal affinity) that is employed in veterinary medicine as an opioid antagonist.

Metazocine is an opioid analgesic related to pentazocine.

Matrine is an alkaloid found in plants from the Sophora genus.

Noribogaine, or 12-hydroxyibogamine, is the principal psychoactive metabolite of the hallucinogenic drug ibogaine.

Adrenorphin, also sometimes referred to as metorphamide, is an endogenous, C-terminally amidated, opioid octapeptide (Tyr-Gly-Gly-Phe-Met-Arg-Arg-Val-NH2) that is produced from proteolytic cleavage of proenkephalin A and is widely distributed throughout the mammalian brain.

Alazocine ((-)-SKF-10,047), or (-)-N-allylnormetazocine ((-)-ANMC), was the first drug discovered to act as a σ1 receptor agonist (Ki = 24 nM).

Dynorphin B, also known as rimorphin, is a form of dynorphin and an endogenous opioid peptide with the amino acid sequence Tyr-Gly-Gly-Phe-Leu-Arg-Arg-Gln-Phe-Lys-Val-Val-Thr.

Leumorphin, also called dynorphin B-29, is a naturally occurring, endogenous opioid peptide.

Nalfurafine (INN, USAN) (brand name Remitch; former developmental code names TRK-820, AC-820, MT-9938) is an antipruritic (anti-itch drug) that is marketed in Japan for the treatment of uremic pruritus in individuals with chronic kidney disease undergoing hemodialysis.

Salvinorin B methoxymethyl ether (2-O-methoxymethylsalvinorin B) is a semi-synthetic analogue of the natural product salvinorin A which is used in scientific research.

Bremazocine is a κ-opioid receptor agonist related to pentazocine.

BRL-52537 is a drug which acts as a potent and highly selective κ-opioid agonist.

ICI-204,448 is a drug which acts as a potent and peripherally selective κ-opioid agonist, with possible uses in the treatment of heart attack as well as anti-itching effects.

GR-89696 is a drug which acts as a highly selective κ-opioid agonist.

ICI-199,441 is a drug which acts as a potent and selective κ-opioid agonist, and has analgesic effects.

LPK-26 is a potent and selective κ-opioid agonist, and has analgesic effects.

Samidorphan (INN, USAN) (developmental code names ALKS-33, RDC-0313), also known as 3-carboxamido-4-hydroxynaltrexone, is an opioid antagonist that preferentially acts as an antagonist of the μ-opioid receptor (MOR).

Cebranopadol (GRT-6005) is a novel opioid analgesic of the benzenoid class which is currently under development internationally by Grünenthal, a German pharmaceutical company, and its partner Depomed, a pharmaceutical company in the United States, for the treatment of a variety of different acute and chronic pain states.

Norbuprenorphine-3-glucuronide (N3G) is a major active metabolite of the opioid modulator buprenorphine.

6'-Guanidinonaltrindole (6'-GNTI) is a κ−δ-opioid receptor selective ligand used in scientific research.