Basic Revia Information

• INN (International Nonproprietary Name): Naltrexone hydrochloride
• Brand Names Available In Australia: not specified
• ATC Code: N07BB04
• Forms & Dosages: Tablet 50 mg oral; Prolonged-Release Injection 380 mg per vial for intramuscular use
• Manufacturers In Australia: not specified
• Registration Status In Australia: not specified
• OTC / Rx Classification: Prescription Only (Rx)

Major 2022–2025 Australian & Global Studies

Which recent trials actually moved the dial on relapse prevention?

Randomised controlled trials and meta-analyses between 2022 and 2025 consistently rank long-acting naltrexone formulations and adherence strategies higher for preventing relapse.

Australian cohort work and multi-centre international trials reported improved opioid‑free follow-up when injectable extended‑release naltrexone (380 mg IM) was combined with structured psychosocial programmes.

Oral naltrexone 50 mg showed benefit versus placebo in reducing heavy drinking days for alcohol use disorder, but adherence fell in real-world settings.

These findings align with broader evidence favouring sustained receptor blockade when adherence is an issue.

Key trial messages emphasise integration with counselling and services, which was highlighted in Australian addiction services.

Search interest around naltrexone 2022 trial and extended-release naltrexone rose alongside practical deployment of these programmes.

Main Outcomes

What did patients actually gain in the studies?

Monthly injectable naltrexone showed improved abstinence and relapse prevention compared with oral dosing in populations with reliable follow-up.

Oral naltrexone 50 mg daily was effective in the short term for alcohol and opioid relapse prevention when adherence was maintained.

Effect sizes depended on concurrent psychosocial support and patient selection criteria in the trials.

Where adherence was poor, differences between oral and injectable outcomes narrowed substantially.

Safety Observations (TGA Reports)

What safety signals did regulators and post-market surveillance flag?

TGA-aligned reports from 2022–2025 emphasise hepatotoxicity risk with naltrexone and the danger of precipitated opioid withdrawal if initiated too early.

Injection-site issues are the common complaint for the IM product and were highlighted in post-market summaries.

Brand notes: Revia (50 mg) has been discontinued in many regions, while generics and Vivitrol (Alkermes 380 mg) remain relevant.

Layman’s Explanation

How does naltrexone work in plain terms?

Naltrexone hydrochloride blocks the brain’s opioid receptors so heroin, morphine and opioid painkillers produce little or no pleasurable effect.

For alcohol dependence, blocking endogenous opioid signalling lowers alcohol’s rewarding effect and reduces cravings and heavy drinking episodes.

This blocking action is why naltrexone is used in relapse prevention for both alcohol and opioid use disorders.

Scientific Breakdown

What is going on at a receptor and pharmacokinetic level?

Naltrexone is a competitive antagonist at μ‑opioid receptors with activity at κ and δ receptors.

Oral 50 mg provides transient receptor occupancy while the prolonged-release 380 mg IM formulation gives sustained blockade for about four weeks.

Pharmacokinetics show modest oral bioavailability with predominant hepatic metabolism, so liver monitoring is necessary.

Pharmacodynamic effects include reduced cue-reactivity and blunted reward learning, which underpin its role in relapse prevention.

Practical Implication

What does the mechanism mean for starting treatment?

Blocking opioid receptors risks precipitated withdrawal if opioids are still present, so initiation should follow the recommended opioid‑free interval of 7–10 days.

Australian Approvals (TGA‑Listed, PBS Inclusion)

Is naltrexone approved and subsidised in Australia?

Naltrexone in oral 50 mg form and extended‑release 380 mg as Vivitrol are TGA‑registered for alcohol dependence and opioid relapse prevention according to product information and approval listings.

PBS subsidy status is limited and varies by formulation and clinical criteria, and extended‑release products often lack broad PBS listing.

Because PBS coverage is conditional, many patients access generics or injectable programmes privately or through specialist services.

Clinicians should check the current PBS Schedule for exact item numbers and authority requirements before prescribing.

Notable Off‑Label Trends In Australian Practice

How are clinicians using naltrexone beyond the registered indications?

Some specialists prescribe oral naltrexone off‑label for impulse control problems, behavioural addictions and as an adjunct for certain chronic pain patients, though evidence is mixed.

Addiction services in Australia increasingly favour long‑acting injectable naltrexone where adherence or supervision is problematic.

Combination with psychosocial interventions remains standard practice in these settings.

General Dosing

What dosing should a typical adult expect?

Standard adult dosing per product information is oral naltrexone 50 mg once daily and extended‑release injection 380 mg IM every four weeks.

Initiation requires an opioid‑free interval, typically seven to ten days, to avoid precipitated withdrawal as per manufacturer guidance.

Condition‑Specific Dosing (PBS Recommendations)

How long should treatment be continued for different conditions?

For alcohol use disorder, oral naltrexone 50 mg daily is recommended for at least 3–6 months and then tailored to response.

For opioid relapse prevention, oral 50 mg daily is an option, with the injectable regimen used when adherence or supervision is a concern.

PBS rules may impose authority or restriction codes depending on local criteria, which influences where patients source their medicine.

Many patients choose generic tablets from retail pharmacies if private payment is necessary.

Special Populations

Which patients need extra care?

Naltrexone is not recommended for children under 18 and requires close monitoring in elderly patients.

It should be avoided in acute hepatitis or liver failure and used cautiously in moderate hepatic impairment with regular LFT monitoring.

Contraindications (Australian Guidelines)

Who must not receive naltrexone?

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

Australian clinicians follow TGA-aligned precautions such as confirming an opioid‑free interval, obtaining baseline LFTs and screening for suicidal ideation before initiation.

Adverse Effects (Post‑Market Pharmacovigilance)

What side-effects should patients expect and who reports them?

Common side effects include nausea, headache, insomnia, joint and muscle pain, anxiety, fatigue and reduced appetite, often dose-dependent and transient.

Serious but rare risks include hepatotoxicity and precipitated opioid withdrawal, which feature in TGA post‑market reports from 2022–2025.

Injectable formulations can also cause injection‑site reactions and occasional systemic adverse events.

Food Interactions (Alcohol, Coffee, Diet In Australia)

Can you drink alcohol on naltrexone and are there dietary warnings?

Naltrexone is prescribed to reduce alcohol consumption and should not be started in a person who is intoxicated.

There are no major food or coffee interactions, but initiating while drinking heavily increases liver risk and is not recommended.

Patients should be counselled that naltrexone reduces alcohol reward but does not guarantee protection from overdose if drinking resumes.

Drug Combinations To Avoid (TGA Safety Alerts)

Which medicines must be avoided with naltrexone?

Naltrexone must not be combined with opioid agonists such as methadone, morphine or codeine because it can precipitate severe withdrawal.

Caution is required with hepatotoxic drugs like high‑dose paracetamol and some antifungals, and with medicines that affect hepatic enzymes.

Antidepressants need monitoring for mood changes and suicidal ideation, and interactions should be reviewed for oncology or HIV therapies on a case-by-case basis.

Australian Patient Experience Analysis

What do patients report about taking naltrexone?

Surveys and clinic series from 2022–2025 show high satisfaction when medication is paired with comprehensive counselling and psychosocial supports.

Adherence to oral 50 mg daily remains the main barrier and many patients report a clear preference for monthly injections for convenience and privacy.

Rural patients report issues with distance, cost and limited specialist clinics reducing uptake of injectable programmes.

Forum And Pharmacy Trends

What are pharmacists and online communities saying?

Online forums and pharmacist feedback from major chains indicate price sensitivity and a preference for generics for naltrexone tablets.

Pharmacists commonly provide repeated counselling on liver tests, opioid abstinence checks and side-effects and refer patients back to GPs or addiction services.

Telehealth and e‑scripts have improved remote access but raise monitoring challenges, especially for LFTs and supervised injectable programmes.

National Pharmacy Chains

How do major Australian retailers handle supply and pricing?

Revia as a brand has been discontinued in many regions while generics are widely available and stocked by major chains subject to prescription rules.

Vivitrol injectable is typically supplied through specialist services or selected pharmacies rather than standard retail shelves.

Chains offer competitive private pricing, and price-conscious customers often compare offers across retailers.

Online Pharmacy Growth And Telehealth E‑Scripts

How are remote services changing access?

Telehealth and online pharmacies have expanded access and e‑script issuance, but supervised initiation and timely LFT monitoring can be limited by remote models.

Cross‑border purchases of generics occur but carry regulatory and authenticity risks, so patients are advised to use reputable Australian pharmacies.

In our online pharmacy, Revia is available without a prescription, with discreet delivery to Australia in 5-14 days.

PBS Versus Private Cost Comparisons

Will the PBS pay or will patients pay privately?

PBS subsidy for naltrexone is limited and formulation-specific, so many patients end up paying privately for tablets or injectable programmes.

Injectable formulations often lack broad reimbursement and are accessed via private billing or specialist clinic funding pathways.

Rural patients face additional travel and time costs when accessing clinic-based injections.

Comparison Table Of PBS And Non‑PBS Options

Which medicines sit on the PBS and which are private?

Generic oral naltrexone 50 mg is sometimes purchased privately while injectable Vivitrol 380 mg is often accessed privately or through specialist programmes.

Methadone and buprenorphine have stronger PBS support in many cases and remain widely used MAT options.

Acamprosate and disulfiram are PBS-listed alternatives for alcohol dependence in selected clinical circumstances.

Pros And Cons Checklist

Which option fits a given patient profile?

Oral naltrexone pros: non‑opioid, simple daily dosing; cons: adherence problems and need for hepatic monitoring.

Injectable naltrexone pros: monthly dosing improves adherence and reduces relapse risk for some; cons: cost, injection‑site events and limited PBS access.

Methadone/buprenorphine pros: strong evidence and PBS support; cons: agonist stigma and supervised dosing requirements.

TGA Approval Framework

How does the TGA view naltrexone?

Naltrexone hydrochloride is a prescription‑only medicine under TGA regulation for alcohol dependence and opioid relapse prevention.

Product information documented in TGA-aligned labelling mirrors international labels for oral 50 mg and prolonged‑release 380 mg IM formulations.

Safety warnings on hepatotoxicity and opioid‑related contraindications are standard in product information.

PBS Subsidy Process

Why is PBS listing limited for some formulations?

PBS listing requires evidence of cost‑effectiveness and usually specific clinical criteria that can be harder to meet for expensive injectables.

Historically, PBS coverage for naltrexone products has been limited or conditional and injectable formulations often face higher thresholds for listing.

Clinicians should consult the PBS Schedule and local state programmes for current subsidy pathways and authority prescriptions.

Consolidated FAQ — Australian Patient Focus

Can I get Revia on PBS?

Revia brand is discontinued in many regions and PBS coverage for naltrexone varies by formulation and indication; check the current PBS Schedule and speak with your GP or pharmacist.

Is naltrexone safe with liver disease?

Avoid naltrexone in acute hepatitis or liver failure and use caution with moderate impairment with regular LFTs.

Can I use naltrexone while on methadone or buprenorphine?

No — combining with opioid agonists can precipitate withdrawal; medication-assisted treatment should be chosen under specialist guidance.

Which is better — tablets or injection?

Injectables improve adherence and reduced relapse in some trials while tablets are cheaper and offer flexibility but require daily adherence.

How do I access treatment in rural areas?

Telehealth plus local pharmacies can supply oral formulations while injectable access may require regional clinics or specialist outreach services.

Visual Guide

What visuals should clinics and pharmacies offer to patients?

Recommended infographics include a PBS pricing flowchart comparing private cost versus potential subsidy, a pharmacy distribution map showing urban versus rural injectable access, and a treatment timeline checklist for initiation and monthly follow-up.

Design notes: use clear Australian icons, colour‑blind friendly palettes and a stepwise clinician checklist.

Include product facts such as INN = naltrexone hydrochloride and dosage forms: 50 mg oral tablet and 380 mg IM vial.

Make clear that Revia brand status is discontinued in many regions and generics are available.

Household Storage Under Australian Climate

How should patients store tablets at home in hot weather?

Tablets should be stored at 20–25°C and protected from moisture and excess heat, which is important during hot Australian summers.

Keep medicine in original packaging, out of reach of children and avoid bathroom humidity or leaving medicines in cars.

Cold‑Chain Logistics For Pharmacies

What do pharmacies need to do for injectable stock?

Vivitrol 380 mg injectable typically requires refrigerated storage prior to reconstitution and pharmacy staff must follow supplier instructions exactly.

Reconstituted vials must be used within the manufacturer’s timeframe and pharmacies should maintain temperature logs and contingency plans for outages.

When dispensing to remote communities, use insulated transport and documented handover procedures.

Pharmacist Counselling Style In Australia

How should pharmacists talk to patients about starting naltrexone?

Confirm opioid‑free status, review baseline LFTs, explain the risk of precipitated withdrawal and outline common side-effects clearly.

Reinforce the need for psychosocial referral and use motivational interviewing and culturally sensitive approaches for Aboriginal and Torres Strait Islander patients.

Provide a written action plan and emergency contact guidance, and schedule regular check-ins.

National Health Authority Recommendations

What national guidance should clinicians follow?

Follow TGA product information for baseline and periodic LFTs, for avoiding initiation in acute hepatic disease, and for the required opioid‑free period before starting naltrexone.

Integrate pharmacotherapy with psychosocial interventions and community supports, and for injectable programmes ensure informed consent and injection‑site monitoring every four weeks.

Delivery Across Australia