Naltrexone

Naltrexone is a synthetic opioid antagonist used primarily in the management of opioid and alcohol dependence. It is a derivative of noroxymorphone with a cyclopropylmethyl substitution, which gives it strong antagonistic activity at opioid receptors, particularly the mu-opioid receptor. Naltrexone blocks the effects of both exogenous (drug-related) and endogenous (naturally occurring) opioids, preventing their euphoric and sedative properties. Unlike naloxone, naltrexone is orally effective, exhibits high potency, and causes prolonged blockade. It is available as naltrexone hydrochloride in oral and injectable forms, with brand names including ReVia, Depade, and Vivitrol. Major safety concerns include the risk of hepatotoxicity, requiring routine monitoring of liver function, and potential for precipitated withdrawal in opioid-dependent patients if used inappropriately.

Other names

Naltrexone hydrochlorideReViaDepadeNalorexAntaxoneVivitrolVivitrexCelupanEN-1639 APTI-901UM 792Nih8503NSC 409767Ccris 1168Nalmefene-3naltrexone HCl

Competitive antagonism at opioid receptors, mainly mu-opioid receptor; Blocks the euphoric and sedative effects of opioids; May modulate reward pathways indirectly in alcohol dependence