Normorphine is an

opiate An opiate, in classical pharmacology, is a substance derived from opium. In more modern usage, the term ''opioid'' is used to designate all substances, both natural and synthetic, that bind to opioid receptors in the brain (including antagonis ...

analogue, the N-demethylated derivative of

morphine Morphine is a strong opiate that is found naturally in opium, a dark brown resin in poppies (''Papaver somniferum''). It is mainly used as a analgesic, pain medication, and is also commonly used recreational drug, recreationally, or to make ...

, that was first described in the 1950s when a large group of N-substituted morphine analogues were characterized for activity. The compound has relatively little opioid activity in its own right, but is a useful intermediate which can be used to produce both

opioid antagonist An opioid antagonist, or opioid receptor antagonist, is a receptor antagonist that acts on one or more of the opioid receptors. Naloxone and naltrexone are commonly used opioid antagonist drugs which are competitive antagonists that bind to the o ...

s such as

nalorphine Nalorphine () (brand names Lethidrone, Nalline), also known as ''N''-allylnormorphine, is a mixed opioid agonist–antagonist with opioid antagonist and analgesic properties. It was introduced in 1954 and was used as an antidote to reverse op ...

, and also potent opioid agonists such as

N-phenethylnormorphine ''N''-Phenethylnormorphine is an opioid analgesic drug derived from morphine by replacing the ''N''-methyl group with β-phenethyl. It is around eight to fourteen times more potent than morphine as a result of this modification, in contrast to m ...

. with its formation from morphine catalyzed by the

liver The liver is a major Organ (anatomy), organ only found in vertebrates which performs many essential biological functions such as detoxification of the organism, and the Protein biosynthesis, synthesis of proteins and biochemicals necessary for ...

enzyme Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. A ...

CYP3A4 Cytochrome P450 3A4 (abbreviated CYP3A4) () is an important enzyme in the body, mainly found in the liver and in the intestine. It oxidizes small foreign organic molecules (xenobiotics), such as toxins or drugs, so that they can be removed from t ...

and

CYP2C8 Cytochrome P4502C8 (abbreviated CYP2C8), a member of the cytochrome P450 mixed-function oxidase system, is involved in the metabolism of xenobiotics in the body. Cytochrome P4502C8 also possesses epoxygenase activity, i.e. it metabolizes long-cha ...

. Normorphine is a controlled substance listed under the Single Convention On Narcotic Drugs 1961 and the laws in various states implementing it; for example, in the United States it is a Schedule I Narcotic controlled substance, with an ACSCN of 9313 and an annual aggregate manufacturing quota of 18 grams in 2014, unchanged from the prior year. The salts in use are the free base hexahydrate (free base conversion ratio 0.715), and hydrochloride (0.833).

References

{{Opioidergics 4,5-Epoxymorphinans Opiates Phenols Secondary alcohols Opioid metabolites