The FDA has approved Vivitrol (naltrexone extended-release injectable IM suspension, from Alkermes) to treat and prevent relapse after patients with opioid dependence have undergone detoxification treatment. Vivitrol is an extended-release formulation of naltrexone administered once a month by intramuscular injection. Naltrexone works to block opioid receptors in the brain to block the effects of drugs like morphine, heroin, and other opioids.

This approval was based on study data comparing Vivitrol to placebo in patients who had completed detoxification and who were no longer physically dependent on opioids. Thirty-six percent of Vivitrol-treated patients were able to stay in treatment for the full six months without using drugs, compared with 23% in the placebo group.

For more information call (800) VIVITROL or visit