Vivitrol is indicated in the treatment of Opioid Use Disorder, and Alcohol Abuse. This special extended release depot injection last 28 days. Naltrexone is a competitive antagonist at the mu-opioid receptor. Therefore it attaches and blocks opioids such as Heroin or Oxycodone from attaching. One of the risks is a person trying to take large doses of opioids to overcome the Naltrexone, can lead life threatening respiratory depression and death. Vivitrol is the injectable form of naltrexone. There is also plain oral naltrexone that works the same way, but needs to be taken daily VIVITROL FEDERAL WAY opioid addiction family practice physician