naltrexone extended release
Adjunctive therapy • Brands: Vivitrol
Last reviewed: 2026-02-12
General information
- Class: Adjunctive therapy
- Common US brands: Vivitrol
- Therapeutic drug monitoring not routinely recommended.
- Last reviewed: 2026-02-12
Dosing & forms
- Forms/strengths: —
- Frequency: —
- Food: —
- Typical range: —
Mechanism (brief)
Monthly extended-release injectable naltrexone (opioid antagonist) used for alcohol dependence and for opioid relapse prevention after detoxification. Requires an opioid-free interval to avoid precipitated withdrawal and carries important injection-site, hepatotoxicity, and overdose-vulnerability warnings (label/guideline).
Metabolism & Half‑life
- Metabolism: Extensive metabolism to 6β-naltrexol via dihydrodiol dehydrogenase (non-CYP) (label), Glucuronide conjugation (label)
- Half‑life: Single-dose range 120–240 h
Therapeutic Drug Monitoring (TDM)
Recommended: No
Monitoring highlights
- —
Sources
- VIVITROL (naltrexone for extended-release injectable suspension) prescribing information — DailyMed (2026)
- The ASAM National Practice Guideline for the Treatment of Opioid Use Disorder: 2020 Focused Update — Journal of Addiction Medicine (2020)
- TIP 63: Medications for Opioid Use Disorder — SAMHSA (2021)
- Comparative effectiveness of extended-release naltrexone versus buprenorphine-naloxone for opioid relapse prevention (X:BOT): a multicentre, open-label, randomised controlled trial — The Lancet (2018)
- The American Psychiatric Association Practice Guideline for the Pharmacological Treatment of Patients With Alcohol Use Disorder — American Journal of Psychiatry (2018)