Vivitrol / ReVia Tapering Guide
naltrexone
Overview
Naltrexone is an opioid antagonist used for alcohol use disorder and opioid use disorder relapse prevention. Low-dose naltrexone (4.5mg, LDN) is used off-label for chronic pain, fibromyalgia, and inflammatory conditions — different mechanism, different evidence base.
50mg tablets (oral); 380mg IM monthly (Vivitrol); 4.5mg compounded (low-dose naltrexone, off-label)
Tablets: 50mg; IM (Vivitrol): 380mg/month; Compounded LDN: 1.5-4.5mg (off-label)
Category C
Mechanism of Action
Competitive antagonist at mu, kappa, and delta opioid receptors. At low doses, paradoxical effects may involve transient receptor blockade and endogenous opioid upregulation.
Taper Notes
For oral naltrexone, most patients can stop without taper. For depot, the long half-life provides a natural taper. Plan for return of cravings.
Hyperbolic Tapering Guidance
Naltrexone is not dependence-forming; the main risk on discontinuation is loss of the medication-supported buffer against the underlying disorder, not pharmacological withdrawal.
Summary written by TaperCommunity, informed by the Maudsley Deprescribing Guidelines (Horowitz & Taylor) and related literature — see Sources & References below. Not affiliated with or endorsed by the Maudsley.
Withdrawal Timeline
Days (oral) or weeks (depot wear-off)
1-2 weeks
Usually 2-4 weeks
Rare for the medication itself; the underlying condition is the main long-term consideration
Common Withdrawal Symptoms
Interactions & Safety
Drug Interactions
- All opioids — naltrexone blocks effects; if opioid is needed for pain, will require much higher doses with careful monitoring
- Yohimbine — additive effects
Contraindications
- Current opioid use or dependence (will precipitate withdrawal)
- Acute opioid withdrawal
- Severe hepatic impairment
Toxicity
Hepatotoxicity (dose-dependent — uncommon at standard doses), nausea, headache, dizziness, anxiety, insomnia, depression. Will precipitate severe withdrawal in opioid-dependent patients.
Pharmacokinetics
ADME Profile
Hepatic via dihydrodiol dehydrogenase.
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Other Drug Profiles
Sources & References
Vivitrol / ReVia (naltrexone) information on this page is sourced from peer-reviewed research, regulatory bodies, clinical guidelines, and patient-advocacy organizations.
Encyclopedic & chemical databases
Neutral, high-authority entity references.
Regulatory sources
Official prescribing information and safety notices.
Peer-reviewed research
Primary literature cited in this taper guide.
Clinical guidelines
Evidence-based deprescribing and prescribing standards.
Deprescribing-specific resources
Clinician-facing references on tapering protocols.
- SAMHSA — Medication-Assisted Treatment — Federal guidance on MAT for opioid use disorder
- Deprescribing.org — opioid algorithm — Evidence-based opioid deprescribing algorithm
- CDC Clinical Practice Guideline for Prescribing Opioids — 2022 CDC guideline on opioid prescribing for chronic pain
Patient-advocacy & lived-experience
Long-running communities documenting withdrawal experience.
- SAMHSA National Helpline — 24/7 confidential support for substance use and mental health
- Mad in America — opioid coverage — Independent journalism on opioid tapering and recovery
- Inner Compass Initiative — Withdrawal Project — Peer-led resources for medication withdrawal
- RxISK — adverse drug reaction reporting — Independent database of patient-reported adverse effects
TaperCommunity does not provide medical advice. Always consult a qualified prescriber before adjusting psychiatric medication.