Bucinnazine
Bucinnazine
Opioid analgesic drug
Bucinnazine (AP-237, 1-butyryl-4-cinnamylpiperazine) is an opioid analgesic drug that was widely used in China to treat pain in cancer patients as of 1986.[1] It is one of the most potent compounds among a series of piperazine-amides first synthesized and reported in Japan in the 1970s.[2][3][4] Bucinnazine has analgesic potency comparable to that of morphine but with a relatively higher therapeutic index.
The drug was initially claimed to be a non-narcotic analgesic. However, subsequent studies have shown bucinnazine and similar acyl piperazines to be potent and selective agonists of μ-opioid receptor (MOR) with relatively low affinity for the δ-opioid receptor and the κ-opioid receptor.[5] In accordance with these studies, results from the intravenous self-administration experiments in rats showed that bucinnazine has a marked reinforcing effect with tolerance and dependence quickly developing.[1] In addition, the morphine antagonist naloxone reverses the effect of bucinnazine and precipitates withdrawal symptoms in bucinnazine treated rats further indicating a mechanism of analgesia mediated via selective agonist activity at μ-opioid receptors.