Benzomorphans

Pentazocine, sold under the brand name Talwin among others, is an analgesic medication used to treat moderate to severe pain. It is believed to work by activating (agonizing) κ-opioid receptors (KOR) and μ-opioid receptors (MOR). As such it is called an opioid as it delivers its effects on pain by interacting with the opioid receptors. It shares many of the side effects of other opioids like constipation, nausea, itching, drowsiness, and respiratory depression, but, unlike most other opioids, it fairly frequently causes hallucinations, nightmares, and delusions. It is also, unlike most other o

Benzomorphan is a chemical compound that is the base for a series of drugs which variably act on the sigma receptors and κ-opioid receptors, including the following compounds:

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

Metazocine is an opioid analgesic related to pentazocine. While metazocine has significant analgesic effects, mediated through a mixed agonist–antagonist action at the mu opioid receptor, its clinical use is limited by dysphoric and hallucinogenic effects which are most likely caused by activity at kappa opioid receptors (where it is a high-efficacy agonist) and/or sigma receptors.

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. It acts preferentially as a κ-opioid receptor partial agonist and to a lesser extent as a μ-opioid receptor partial agonist.

Ethylketazocine (WIN-35,197-2), is an opioid drug of the benzomorphan family which has been used extensively in scientific research in the last few decades as a tool to aid in the study of the κ-opioid receptor. However, due to its relatively poor selectivity for the κ-opioid receptor over the μ- and δ-opioid receptors (of which it has approximately 80% and 20% of the affinity for, respectively, in comparison), as well as its relatively poor intrinsic activity at all sites (i.e., acts as a partial agonist with mixed agonist and antagonist properties), it has been mostly replaced in recent time

Alazocine (developmental code name -10047), also known more commonly as '''N-allylnormetazocine (NANM'''), is a synthetic opioid analgesic of the benzomorphan family related to metazocine, which was never marketed. In addition to its opioid activity, the drug is a sigma receptor agonist, and has been used widely in scientific research in studies of this receptor. Alazocine is described as a potent analgesic, psychotomimetic or hallucinogen, and opioid antagonist. Moreover, one of its enantiomers was the first compound that was found to selectively label the σ1 receptor, and led to the discover

Cyclazocine is a mixed opioid agonist/antagonist related to dezocine, pentazocine and phenazocine. It is in the benzomorphan and benzazocine family of drugs. It is a κ-opioid receptor agonist and μ-opioid receptor partial agonist, and also has high affinity for the δ-opioid receptor.

Bremazocine is a κ-opioid receptor agonist related to pentazocine. It has potent and long-lasting analgesic and diuretic effects. It has 200 times the activity of morphine, but appears to have no addictive properties and does not depress breathing. The crystal structure of bremazocine was determined in 1984

Cogazocine (INN) is an opioid analgesic of the benzomorphan family which was never marketed.

Ketazocine (INN), also known as ketocyclazocine, is a benzomorphan derivative used in opioid receptor research. Ketazocine, for which the receptor is named, is an exogenous opioid that binds to the κ opioid receptor.

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. It acts as a partial agonist of the μ- and δ-opioid receptors, with less intrinsic activity at the former receptor and more at the latter receptor (hence, it behaves more antagonistically at the former and more agonistically at the latter), and produces antinociceptive effects in animal studies.

Volazocine is an opioid analgesic of the benzomorphan class which was never marketed.