What is "naltrexone"

n. An opiate antagonist used to treat opioid dependence

n. an oral antagonist against the action of opiates

Naltrexone is a drug that reverses the effects of opioids and is used primarily in the management of alcohol dependence and opioid dependence.

The closely related medication methylnaltrexone is used to treat opioid-induced constipation. Nalmefene is a very similar drug that is used for the same purposes as naltrexone. Naltrexone should not be confused with naloxone nor nalorphine, which are used in emergency cases of opioid overdose.

In the US, naltrexone tablets cost between $0.93 and $12.14 per day. It is marketed as its hydrochloride salt, naltrexone hydrochloride, under the trade names Revia and Depade. A once-monthly extended-release injectable formulation is marketed under the trade name Vivitrol.