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Brand: Vivitrol
Published 2026-02-05 · Last reviewed 2026-02-12 · 5 references
Content sourced from FDA labeling (DailyMed) and peer-reviewed literature.
Extended-release naltrexone (Vivitrol) is a monthly intramuscular (IM) formulation of naltrexone, an opioid receptor antagonist. It is indicated for alcohol dependence and for opioid dependence relapse prevention after detoxification (label).
An opioid-free interval is required before initiation. Labeling recommends at least 7–10 opioid-free days to avoid precipitated withdrawal that can be severe enough to require hospitalization (label).
Because it is long acting and cannot be removed once injected, success depends on safe initiation, injection access, and follow-up reliability (label/clinical).
The X:BOT trial highlights a key implementation tradeoff: among patients who successfully initiate, outcomes with extended-release naltrexone and buprenorphine/naloxone were similar, but induction onto extended-release naltrexone had higher early failure due to the detoxification barrier (trial/clinical).
The compare view, extended-release naltrexone evidence feed, and print page support shared decision-making in patients with overlapping alcohol use disorder and opioid use disorder.
Often selected when patients prefer an opioid-antagonist approach, can complete detoxification, and can reliably attend monthly injections. Barriers include detoxification requirements, injection logistics, and boxed safety considerations (label/clinical).
View labelExactRefer to the Glossary entry on Neurotransmitters for background on receptor systems involved in serious mental illness.
Naltrexone is a competitive opioid receptor antagonist with highest affinity for μ-opioid receptors. It blocks the effects of exogenous opioids and is used for relapse prevention in OUD and for reducing heavy drinking outcomes in some patients with alcohol use disorder (AUD) (label/clinical).
Because blockade can be overcome by very high opioid doses, attempts to “override” naltrexone can result in fatal opioid overdose; this is a central safety counseling point (label/clinical).
Because missed injections can create predictable gaps in blockade, adherence planning and follow-up scheduling are practical determinants of benefit (clinical).