“Opioid Use Disorders There are several medications approved for use with opioid users. These fall into two categories: 1) blocking the effects of opioids, and 2) replacing the abused opioid with a different, longer-acting opioid for maintenance on that medication. Opioid replacement or maintenance therapy has a long and documented history of effectiveness and safety. Opioid blocking medications, while basically safe, have been poorly received by the client community. We hope that the effectiveness profile of blockers changes with the advent of new, long-acting (one-month) injectable blockers (Vivitrol), but evidence is still being collected. Blockers: Naltrexone/Vivitrol: This blocks opioid receptors (yes, the same naltrexone from the alcohol category, but used for opioids for an entirely different effect). Naltrexone is given daily and orally and therefore has compliance problems because people can simply stop taking the medication and get high within a couple of days. Vivitrol, an injectable form of naltrexone that blocks opioid receptors for one month, is showing promising results in improving compliance. This”