Ketazocine also known as ketocyclazocine, is a benzomorphan

Benzomorphan

Benzomorphan is a chemical compound.It is the base for a series of drugs which variably act on the opioid and sigma receptors, including, but not limited to, the following compounds:...

 derivative used in opioid receptor

Opioid receptor

Opioid receptors are a group of G protein-coupled receptors with opioids as ligands. The endogenous opioids are dynorphins, enkephalins, endorphins, endomorphins and nociceptin. The opioid receptors are ~40% identical to somatostatin receptors...

 research. Ketocyclazocine is an exogenous

Exogenous

Exogenous refers to an action or object coming from outside a system. It is the opposite of endogenous, something generated from within the system....

 opioid that binds to the kappa opioid receptor

Kappa Opioid receptor

The κ-opioid receptor is a protein that in humans is encoded by the OPRK1 gene. The κ-opioid receptor is one of five related receptors that bind opium-like compounds in the brain and are responsible for mediating the effects of these compounds...

.

Activation of this receptor causes a decrease in pain sensations and increased sleepiness but can also cause psychological symptoms such as feelings of unease, paranoia

Paranoia

Paranoia [] is a thought process believed to be heavily influenced by anxiety or fear, often to the point of irrationality and delusion. Paranoid thinking typically includes persecutory beliefs, or beliefs of conspiracy concerning a perceived threat towards oneself...

, and hallucinations. It also causes an increase in urine production because it inhibits the release of vasopressin. (Vasopressin

Vasopressin

Arginine vasopressin , also known as vasopressin, argipressin or antidiuretic hormone , is a neurohypophysial hormone found in most mammals, including humans. Vasopressin is a peptide hormone that controls the reabsorption of molecules in the tubules of the kidneys by affecting the tissue's...

 is an endogenous

Endogenous

Endogenous substances are those that originate from within an organism, tissue, or cell. Endogenous retroviruses are caused by ancient infections of germ cells in humans, mammals and other vertebrates...

substance that assists in regulating fluid and electrolyte balance in the body and decreases the amount of water released into the urine.)

Unlike other opioids, substances that only bind to the kappa receptor theoretically do not impair the normal drive to breathe.