Medication-assisted treatment for opioid addiction: methadone and buprenorphine.

Among agents for treatment of opioid addiction, methadone is a full mu-opioid receptor agonist, whereas buprenorphine is a partial agonist. Both are long-acting. Buprenorphine has a superior safety profile. Methadone is formulated for oral administration and buprenorphine for sublingual administration. A subdermal buprenorphine implant with a 6-month duration of action is being considered for approval by the U.S. Food and Drug Administration. Both medications reduce mortality rates and improve other outcomes. Data from a recent randomized controlled comparison of both medications (N = 1269) show better treatment retention with methadone but reduced illicit opioid use early in treatment with buprenorphine. Human immunodeficiency virus (HIV) risk behaviors were measured using the Risk Behavior Survey at baseline, 12 weeks, and 24 weeks for study completers. In the 30 days prior to treatment entry, 14.4% of the completers randomized to treatment with buprenorphine (n = 340) and 14.1% of the completers randomized to methadone treatment (n = 391) shared needles. The percent sharing needles decreased to 2.4% for buprenorphine and 4.8 for methadone in the 30 days prior to Week 24 (p < 0.0001). In the 30 days prior to treatment entry, 6.8% of the completers randomized to buprenorphine and 8.2% of the completers randomized to methadone had multiple sexual partners, with only 5.2% and 5.1%, respectively, reporting multiple partners at Week 24 (p < 0.04).