NUBAIN (nalbuphine hydrochloride) is a synthetic opioid agonist-antagonist analgesic of the phenanthrene series. It is chemically related to both the widely used opioid antagonist, naloxone, and the potent opioid analgesic, oxymorphone. Chemically nalbuphine hydrochloride is 17-(cyclobutylmethyl)-4,5α-epoxymorphinan-3,6α,14-triol hydrochloride. Nalbuphine hydrochloride molecular weight is 393.91 and is soluble in H2O (35.5 mg/mL @ 25ºC) and ethanol (0.8%); insoluble in CHCl3 and ether. Nalbuphine hydrochloride has pKa values of 8.71 and 9.96.
Nubain is an opiate used by fitness enthusiasts to increase their pain threshold.