51481-60-8

White or almost white, hygroscopic, crystalline powder.

Antagonist (to narcotics).

Naloxone Hydrochloride Dihydrate is a specific opioid antagonist. Narcotic antagonist.

Narcan (Bristol-Myers Squibb); Narcan (Endo).

Competitive antagonist for μ, κ, δ, and σ opioid receptors; blocks the action of σ-agonists at opioid sites. Naloxone′s antagonistic effect last for about 45 min and thus, requires repeated dosage. It results in critical side effects such as pulmonary edema.

This opiate antagonist has been recrystallised from EtOH/Et2O or H2O. It is soluble in H2O (5%) and EtOH but insoluble in Et2O. The free base has m 184o (177-178o also reported) after recrystallisation from EtOAc, and [] D -194.5o (c 0.93, CHCl3). [Olofson et al. Tetrahedron Lett 1567 1977, Gold et al. Med Res Rev 2 211 1982.]