Naltrexone is a prescription medication used to treat alcohol use disorder and opioid use disorder. It helps you stop using these substances and remain off them.
Naltrexone belongs to a class of drugs known as opioid antagonists and works by blocking the mu opioid receptor. It blocks the effects of alcohol and opioid medications, preventing the intoxication these substances cause. Naltrexone also modifies how the hypothalamus, pituitary gland and adrenal gland (hypothalamic-pituitary-adrenal axis, HPA axis) interact to suppress the amount of alcohol consumed.
Naltrexone comes as an extended-release intramuscular injection (Vivitrol) and as oral tablets. The branded versions of naltrexone tablets (Revia, Depade) have been discontinued, but generic versions are available.