Naltrexone is a drug that’s used in the treatment of opioid dependence. It blocks the effects of opioids, and some studies have shown that it may be effective in suppressing cravings.

Naltrexone was introduced in 1984 by the pharmaceutical company DuPont Merck, as an alternative to methadone for managing heroin addiction and dependence.

It’s also used as a part of therapy for alcohol dependence. It can relieve some, but not all of the discomfort people feel when they stop drinking alcohol or taking opiates or sedatives (e.g., benzodiazepines).

Naltrexone may be very effective in suppressing alcohol withdrawal symptoms, although it does not seem to help with relapse after people stop using alcohol.

People taking naltrexone for alcohol dependence often try to avoid drinking by cutting down on or stopping drinking, or go without alcohol altogether. But as long as they have naltrexone in their system, they’ll still get a little bit of a buzz if they drink an alcoholic drink containing the drug.

In 2013, the United States Food and Drug Administration (FDA) approved Vivitrol, which is made by up-and-coming pharmaceutical company Biohaven Pharmaceuticals.