Naloxazone is an irreversible

μ-opioid receptor The μ-opioid receptors (MOR) are a class of opioid receptors with a high affinity for enkephalins and beta-endorphin, but a low affinity for dynorphins. They are also referred to as μ(''mu'')-opioid peptide (MOP) receptors. The prototypical � ...

antagonist which is selective for the μ₁ receptor subtype. Naloxazone produces very long lasting antagonist effects as it forms a covalent bond to the active site of the μ-opioid receptor, thus making it impossible for the molecule to unbind and blocking the receptor permanently until the receptor is recycled by endocytosis. Naloxazone is the

hydrazone Hydrazones are a class of organic compounds with the structure . They are related to ketones and aldehydes by the replacement of the oxygen =O with the = functional group. They are formed usually by the action of hydrazine on ketones or aldehyde ...

analog of

naloxone Naloxone, sold under the brand names Narcan (4 mg) and Kloxxado (8 mg) among others, is a medication used to reverse or reduce the effects of opioids. It is commonly used to counter decreased breathing in opioid overdose. Effects begin withi ...

. It has been reported that naloxazone is unstable in acidic solution, dimerizing into the more stable and much more potent antagonist naloxonazine via the free NH₂ of the hydrazone to form an

azine Azines are a functional class of organic compounds with the connectivity RR'C=N-N=CRR'. These compounds are the product of the condensation of hydrazine with ketones and aldehydes, although in practice they are often made by alternative routes ...

linkage. Under conditions in which no naloxonazine formation could be detected, naloxazone did not display irreversible μ opioid receptor binding.

References

Mu-opioid receptor antagonists 4,5-Epoxymorphinans Phenols Tertiary alcohols Cyclohexanols Allylamines Ethers Semisynthetic opioids Hydrazones Alkylating agents Irreversible antagonists {{nervous-system-drug-stub

See also

References