| Treatment outcomes | long-acting Nalmefene (Nalmefene Consta 393.1 mg) (n = 1500) | extended-release Naltrexone (Vivitrol 380 mg) (n = 1500) | Treatment effect |
| 3200 Assessed for eligibility 3000 Randomized | 1500 Randomized to receive Long-acting intramuscular formulation of Nalmefene (Nalmefene Consta 393.1 mg) | 1500 Randomized to receive Extended-release Naltrexone (Vivitrol 380 mg) | 1815 Completed 12 weeks treatment |
| Opioid relapse patients weeks 4 - 12 | 14% (n = 210) | 67% (n = 855) | (P < 0.0001) |
| Opioid-free patients weeks 4 - 12 | 86% (n = 1290) | 43% (n = 645) | (P < 0.0001) |
| Retention in treatment | 83% (n = 1245) | 38% (n = 570) | (P < 0.0001). |
| Median time in treatment | >84 days | 48 days | (P < 0.0001). |
| Adverse reaction and adverse events | 31.7% (n = 465) | 60.0% (n = 900) | (P < 0.001) |