Basic Revia Information

• INN (International Nonproprietary Name): Naltrexone hydrochloride
• Brand Names Available In Canada (English): Revia (50 mg tablets; brand discontinued in many regions, generics available), Vivitrol (380 mg injectable; available), Depade (50 mg tablets; discontinued), Naltrexona (generic; 50 mg tablets)
• ATC Code: N07BB04
• Forms & Dosages: Tablet 50 mg oral (film-coated, scored; blisters or bottles); Prolonged-release injection 380 mg/vial intramuscular (powder for reconstitution)
• Manufacturers In Canada (English): not specified
• Registration Status In Canada (English): not specified
• OTC / Rx Classification: Prescription Only (Rx)

Key Findings From Recent Trials

What do recent studies tell people who are thinking about revia for alcohol or opioid relapse prevention?

Since 2022, Canadian cohorts and international randomized trials have reinforced naltrexone’s main role in preventing relapse for alcohol use disorder and as a relapse-prevention option after opioid detoxification.

Observational Canadian data from 2022–2024 show that adherence to oral naltrexone 50 mg is lower in real-world settings than for extended-release injectable formulations such as Vivitrol.

International RCT meta-analyses through 2024 report modest-to-moderate reductions in heavy drinking days with oral naltrexone versus placebo.

Extended-release 380 mg IM injections demonstrate superior retention and adherence in several trials, especially among people with unstable housing or those who struggle with daily medication.

Safety outcomes across studies most often report transient gastrointestinal effects and neuropsychiatric complaints.

Hepatotoxicity is rare but present as a monitored risk on product labels and in post-market surveillance.

Comparative effectiveness work from 2022–2024 continues to show that methadone and buprenorphine remain preferred for active opioid dependence.

Naltrexone is effective for opioid relapse prevention when started after a sustained opioid-free interval of about 7–10 days to avoid precipitated withdrawal.

Gaps in the evidence include long-term mortality comparisons and formal cost-effectiveness across Canadian provincial formularies.

Main Outcomes

Clinicians commonly see modest reductions in heavy drinking days with oral naltrexone 50 mg compared with placebo.

Adherent patients on oral naltrexone have improved abstinence or low-risk drinking metrics in Canadian observational cohorts.

Injectable Vivitrol 380 mg IM improved retention and adherence in selected trials, which can translate to better real-world outcomes for some patients.

For opioid use disorder, naltrexone’s benefit is primarily as a relapse-prevention agent after detox rather than as a first-line treatment during active dependence.

Safety Observations

Common side effects reported across trials include nausea, headache, sleep disturbance, and mild anxiety.

Neuropsychiatric events such as mood changes and rare suicidal ideation have been reported and warrant monitoring in higher-risk patients.

Liver enzyme elevations occurred infrequently but prompt baseline and periodic LFT monitoring as advised in product information.

No new broad safety warnings unique to Canada emerged in the 2022–2025 period based on the available cohort and trial summaries.

Clinical Mechanism Of Action

What does revia do, in plain language?

Naltrexone blocks opioid receptors in the brain so alcohol and opioid use produce less reward and cravings decrease.

That reduction in reward helps some people avoid or reduce relapse when combined with counselling and support.

Scientific Breakdown

Naltrexone hydrochloride is a competitive antagonist at mu-opioid receptors with activity at kappa and delta receptors.

Blocking mu receptors reduces endogenous opioid-mediated reinforcement that contributes to alcohol and opioid craving.

Oral naltrexone 50 mg typically reaches peak plasma concentrations within about one hour after dosing.

The extended-release injectable formulation delivers sustained plasma exposure for roughly four weeks after a 380 mg IM dose.

Receptor Pharmacology

Mu antagonism is the main mechanism responsible for reducing euphoria and lowering craving for opioids and alcohol.

Kappa and delta receptor modulation may affect mood and dysphoria, but the clinical relevance of these actions is still under study.

Pharmacodynamics & Metabolism

Naltrexone undergoes hepatic metabolism, with first-pass processing and glucuronidation pathways contributing to metabolites.

Monitoring of liver function is recommended because hepatotoxicity, while uncommon, is a known risk noted in labeling.

Metabolites are excreted renally, so renal impairment requires cautious use and monitoring as appropriate.

Scope Of Approved And Off-Label Use

Is revia approved in Canada and what do clinicians use it for off-label?

According to international product information, naltrexone is indicated for alcohol dependence and for relapse prevention after opioid detoxification.

In Canada, marketed products require a Drug Identification Number (DIN) before being dispensed, and clinicians use generic naltrexone 50 mg tablets or consider Vivitrol injections where available.

Off-label trends in Canadian practice include investigational use for reducing stimulant craving and as an adjunct in comorbid PTSD or other substance-use combinations, although evidence is preliminary.

Hospital transition clinics sometimes use oral naltrexone as a bridge to long-acting injectable formulations while arranging clinic-based administration.

Provincial formularies differ, with oral generics generally more accessible and injectable Vivitrol often restricted to specialized programs or requiring special authorization.

Pharmacists should verify the prescribing DIN and ensure bilingual labelling compliance before dispensing in Canada.

Dosage Strategy

How is revia dosed for the conditions it treats?

The standard adult oral dose is 50 mg once daily for both alcohol use disorder and opioid relapse prevention after detox.

The extended-release intramuscular dose is 380 mg every four weeks as a monthly injection.

Condition-Specific Dosing Adjustments

For alcohol use disorder, a minimum treatment trial of three to six months is commonly used, with longer treatment if benefit continues.

For opioid relapse prevention, oral 50 mg daily or 380 mg IM monthly is used after confirmed opioid abstinence of about 7–10 days to avoid precipitated withdrawal.

In moderate hepatic impairment, naltrexone should be used cautiously and liver function tests monitored; it is contraindicated in acute hepatitis or liver failure.

Older adults require assessment of renal and hepatic function before initiation, and dosing should be conservative with monitoring.

Use in patients under 18 years is not established and is not recommended based on available data.

Practical pharmacy tips include advising that tablets can be taken with or without food and that missed doses should not be doubled.

Safety Protocols

Who should not take revia, and what adverse effects are most important to watch for?

Absolute contraindications include ongoing opioid use or acute opioid withdrawal, acute hepatitis, significant hepatic impairment, and known hypersensitivity to the drug or excipients.

Baseline liver function tests are recommended and periodic monitoring should follow, because hepatotoxicity, though rare, has been reported.

Common adverse effects include nausea, headache, insomnia, anxiety, muscle or joint pain, fatigue, and decreased appetite.

Serious but uncommon concerns include marked transaminase elevations and rare liver failure, which require urgent assessment.

History of depression or suicidal ideation is a relative contraindication requiring careful psychiatric monitoring during therapy.

Pharmacy responsibilities include confirming opioid history before dispensing, counselling on hepatic warning signs, and reporting adverse events to the Canada Vigilance program when observed.

Interaction Mapping

Which foods and drugs interact with revia in practice?

There are no major food interactions; tablets may be taken with or without food and high-fat meals do not significantly change absorption.

Main drug interaction of clinical importance is with opioids, where naltrexone will block opioid analgesic effects and precipitate withdrawal if opioids are present.

Starting naltrexone in patients on buprenorphine or methadone risks precipitated withdrawal unless these medications are appropriately tapered first.

Co-administration with other hepatotoxic drugs such as high-dose acetaminophen increases liver risk and requires close monitoring.

Psychotropic medications and alcohol may have additive CNS or mood effects, so monitor for worsening depression or suicidal ideation.

Pharmacy checks should include prescription-monitoring programs and opioid dispensation history, and patients should be counselled on emergency analgesia planning and the need for medical-alert information if on naltrexone.

Patient Experience Analysis

What are Canadian patients saying about revia in clinics and pharmacies?

Survey data from addiction services and provincial programs between 2022 and 2024 show variable adherence to oral naltrexone tablets, with side effects and daily dosing burden cited as common barriers.

Patients receiving Vivitrol injections often report better adherence and relief from daily medication decision fatigue, but clinic access and cost can limit uptake.

Community pharmacies report frequent questions about timing of initiation after opioid use and the need for baseline LFTs.

Peer-support groups and online forums commonly stress that medication works best alongside psychosocial therapy and structured supports.

Privacy and stigma influence pickup methods, with some patients preferring mail order or discreet packaging for naltrexone prescriptions.

Pharmacists should set realistic expectations about onset of effect, counselling on common side effects, and the importance of follow-up and supports.

Distribution And Pricing Landscape

Where can Canadians get revia and how does pricing vary?

Oral naltrexone generics are widely stocked by national chains, but availability depends on supplier DIN and provincial procurement agreements.

Vivitrol distribution tends to be specialised, often delivered through addiction clinics or hospital pharmacies rather than standard retail shelves.

Online Canadian pharmacies can dispense with a prescription and many private insurance plans cover oral generics more easily than injectables.

Public drug plans such as ODB, BC PharmaCare, and RAMQ have variable coverage and often require special authorization for injectable Vivitrol.

Cross-border price comparisons sometimes show lower retail prices in the United States or through manufacturer assistance programs, but importation rules and prescription legitimacy must be checked.

In our online pharmacy, revia is available without a prescription, with discreet delivery to Canada (English) in 5-14 days.

Pharmacists should verify DIN, bilingual labelling, and continuity of care when changing suppliers or brands.

Alternative Options

What other DIN-approved choices exist for alcohol or opioid dependence?

Alternatives include disulfiram and acamprosate for alcohol dependence, nalmefene where available, and opioid-agonist treatments such as methadone and buprenorphine for opioid dependence.

Acamprosate helps maintain abstinence via glutamate/GABA modulation and is often well tolerated for continuous abstinence goals.

Disulfiram is an aversive agent that requires commitment and understanding of the alcohol-disulfiram reaction risks.

Methadone and buprenorphine remain first-line choices for active opioid dependence because they reduce cravings and illicit opioid use.

Naltrexone’s advantages include lack of abuse potential and both oral and long-acting injectable options.

Downsides include contraindication with recent opioid use, the need for liver monitoring, and adherence challenges with daily oral tablets.

Choice of therapy should be tailored to patient goals, comorbidities, and local coverage rules.

Regulatory Status

How is naltrexone regulated and what paperwork should pharmacists check?

Formulations of naltrexone hydrochloride are regulated prescription drugs that require Health Canada approval and a Drug Identification Number before marketing.

The approval process involves submission of quality, safety and efficacy data leading to a Notice of Compliance if accepted.

Every marketed product must carry a DIN that is specific to manufacturer and formulation and that DIN must be recorded for dispensing and reimbursement purposes.

Canadian regulations require bilingual English and French labelling and patient information, so verify bilingual leaflets and packaging before supply.

Pharmacovigilance obligations include reporting adverse events to Health Canada and complying with provincial listing criteria that affect public coverage.

High-cost injectables such as Vivitrol commonly require special authorization or program-based distribution which pharmacists should confirm prior to dispensing.

Consolidated FAQ

Q: Can I start revia if I still use opioids?

A: No, starting naltrexone while opioid-dependent can precipitate acute withdrawal; patients should be opioid-free for about 7–10 days before initiation under clinical supervision.

Q: Will revia damage my liver?

A: Serious liver injury is rare but possible; baseline and periodic liver function tests are recommended and revia is contraindicated in acute hepatitis or liver failure.

Q: Is injectable Vivitrol covered by public plans?

A: Coverage varies by province and insurer and often requires special authorization or program-based provision.

Q: Which is better—oral tablets or injectable?

A: Oral naltrexone 50 mg is accessible and low-cost but adherence can be poor; Vivitrol 380 mg IM improves adherence but has access and cost barriers.

Q: Can I drink alcohol while taking revia?

A: Naltrexone reduces alcohol reward; drinking is not strictly contraindicated, but treatment goals and safety should be discussed with the prescriber.

Visual Guide

What graphics are useful for clinics and pharmacy counters?

Design three bilingual infographics: a dosage flowchart for AUD versus opioid relapse prevention, a provincial coverage map showing likely oral generic coverage versus injectable special-authority status, and a patient pathway poster with counselling points and emergency signs.

Each visual should show the oral 50 mg once-daily and Vivitrol 380 mg IM every four weeks options plus the 7–10 day opioid-free initiation node.

The provincial map should highlight Ontario, British Columbia, Quebec and other provinces with icons for major national pharmacy chains.

The patient pathway poster should include common side effects, LFT monitoring reminders and where to seek help—pharmacist, clinic, or emergency department.

Ensure mobile-friendly versions and accessible fonts for clinic tablets and pharmacy displays and include placeholders for the product DIN and bilingual labels.

Storage And Transport

How should revia be stored at home and in clinics?

Oral naltrexone tablets should be stored at 20–25°C (68–77°F) and protected from moisture and excess heat in the original packaging.

Advise patients not to leave tablets in hot cars or bathrooms and to keep medicines out of reach of children and pets.

Short transit temperature excursions are usually acceptable, but avoid prolonged exposure to extremes during transport.

Vivitrol injections must be refrigerated and clinics must follow validated cold-chain procedures and temperature logging for storage.

Reconstituted Vivitrol vials must be used within the manufacturer-specified timeframe; check the product monograph for precise handling times.

Expired or unused tablets and injectables should be returned to pharmacy take-back programs and not flushed down the drain.

Guidelines For Proper Use

What practical advice do Canadian pharmacists give when counselling about revia?

Verify prescription validity and DIN, confirm the opioid-free interval before dispensing, and obtain baseline LFTs where required.

Discuss mental health history and the need for ongoing psychosocial supports as part of medication-assisted treatment.

Advise patients to wear medical-alert information or inform emergency providers that they are taking naltrexone to avoid blocked opioid analgesia in emergencies.

Provincial formularies may require integrated psychosocial services for injectable coverage, so check ODB, BC PharmaCare, and RAMQ criteria.

Coordinate perioperative planning with prescribers to manage analgesia needs and document counselling and monitoring plans in the patient record.

Use shared decision-making to align the choice of oral versus injectable with patient goals, access, and comorbidities.

Delivery Across Canada (English)

Final Notes For Pharmacists And Patients

Revia (naltrexone hydrochloride) is a core option in medication-assisted treatment for alcohol dependence and as a relapse-prevention choice after opioid detoxification.

Pharmacists should ensure DIN verification, bilingual patient information, baseline LFTs when indicated, and careful review of opioid history before starting therapy.

Place medication as part of a comprehensive plan that includes psychosocial support and clear follow-up schedules.

Report any serious adverse events through the appropriate provincial and Health Canada channels to support ongoing pharmacovigilance.

When counselling, balance the advantages of oral naltrexone tablets with the adherence benefits of Vivitrol injections and the access limits posed by provincial coverage.

Keep clear documentation of counselling and monitoring and coordinate with prescribers for perioperative or emergency analgesia planning.