Revia (Naltrexone) – Patient Guide (Australia)

Revia® (naltrexone) is a medicine used to help certain conditions related to opioid use and to reduce cravings and relapse risk associated with alcohol dependence in some people. This guide is designed to help you understand how naltrexone works, how it’s typically taken, what to expect, and what to watch for—so you can use it safely and effectively.

Important: Always follow the directions provided by your healthcare professional and read the consumer medicine information (CMI) for your specific product. Information in this page supports understanding, not replacing personalised medical advice.

Basic product information

How Revia (naltrexone) works

Naltrexone is an opioid receptor antagonist. It attaches to opioid receptors in the brain and other parts of the body, and helps block the effects of opioids such as heroin, oxycodone, morphine, codeine and others.

Because it blocks opioid receptors:

• It can reduce the rewarding effects associated with opioid use.
• In some people, it helps support abstinence by decreasing reinforcement and cravings.
• For alcohol dependence, naltrexone may reduce the pleasure/reward pathways involved in alcohol consumption (the exact mechanism in alcohol use is complex, but involves the brain’s opioid-related signalling systems).

Mechanism of action (more detail)

Opioid receptors (primarily mu, but also other opioid receptor types) are involved in the body’s response to opioids and—indirectly—in alcohol-related reward. By competitively antagonising these receptors, naltrexone:

• Prevents opioid agonists from exerting their typical effects.
• May influence downstream neurotransmitter release that contributes to craving and relapse cycles.

After taking naltrexone, if an opioid is taken, its effects may be reduced or blocked. This can be helpful in relapse prevention. However, attempting to “override” the blockade by taking more opioids can be dangerous and can lead to serious harm.

Pharmacokinetics: how your body processes naltrexone

Pharmacokinetics refers to what the body does to a medicine—absorption, distribution, metabolism and elimination.

• Absorption: Naltrexone is absorbed after oral dosing and reaches peak levels within a few hours (exact timing may vary by individual and formulation).
• Distribution: It distributes into body tissues, including the central nervous system.
• Metabolism: Naltrexone is metabolised mainly in the liver to an active metabolite called 6β-naltrexol.
• Elimination: Most metabolites are excreted through the kidneys (urine).
• Half-life: Naltrexone and its metabolite have elimination half-lives that support daily dosing in many clinical plans.

Liver health matters: Because metabolism involves the liver, people with liver impairment may require extra caution and monitoring.

Typical uses in Australia

Revia (naltrexone) is commonly used as part of a comprehensive treatment plan for:

• Alcohol dependence: to help reduce the risk of relapse and assist with maintenance of abstinence or reduction of heavy drinking in some individuals.
• Opioid dependence: to help prevent opioid relapse by blocking opioid effects after detoxification/when opioids are no longer active in the body.

It’s usually combined with supportive services such as counselling, psychosocial therapy, addiction support groups, and other strategies that address triggers and long-term recovery.

Indications: who it may be suitable for

Suitability depends on your medical history, current substance use status, and health conditions. In general, naltrexone may be considered when:

• The goal is to reduce alcohol-related relapse risk (for alcohol dependence).
• The person is opioid-free (or already detoxified) and the goal is relapse prevention by blocking opioid effects.
• There are clear treatment goals and a plan for ongoing support.

Not for everyone: If you currently use opioids, have recent opioid exposure, or may have opioids in your system, naltrexone can precipitate withdrawal and is not appropriate without careful clinical evaluation.

Dosing: typical adult regimen

Dosage should be individualised. The following provides general expectations. Your prescriber may adjust the dose based on your response, tolerability, and liver function.

Alcohol dependence

• Commonly started at a lower dose initially (in some protocols) and then continued.
• Many regimens use a daily tablet schedule.

Opioid dependence (relapse prevention)

• Usually started after ensuring you have no opioids in your system.
• A specialist plan may include an observation period to reduce the risk of precipitated withdrawal.
• The dose is typically daily once opioid abstinence is confirmed.

Do not change the dose or stop/start without guidance. Stopping may reduce the protective effect against cravings/relapse.

Timing: when to take Revia

For most people, Revia is taken:

• Once daily at about the same time each day
• With or without food (see food interactions below)

Missed dose: If you miss a dose, take it when you remember unless it’s close to the time for your next dose. Don’t double up to make up for a missed tablet. If you’re unsure, ask your pharmacist.

Starting: If you are beginning naltrexone, follow the exact start plan provided—particularly important for opioid dependence due to withdrawal risk.

Food interactions

Naltrexone is generally considered not strongly affected by food. You can typically take it:

• With food to reduce stomach discomfort, or
• Without food if it suits you

If you experience nausea or stomach upset, taking the dose with a meal may help.

Alcohol interactions

Revia is used to support alcohol dependence treatment, but it does not mean it’s safe to drink heavily while taking it.

Key points:

• Naltrexone may reduce the reinforcing effects of alcohol for some people, but you may still experience alcohol’s effects on judgement, coordination, and safety.
• Combining alcohol with any treatment plan can increase risk of relapse, accidents, or health complications.
• Because alcohol can affect the liver, ongoing heavy drinking can worsen liver health—important since naltrexone is metabolised by the liver.

If you’re drinking, aim for safer drinking limits (as advised by your healthcare professional) and seek support if you feel at risk of losing control.

Medicine interactions: important examples

Naltrexone’s main interaction risks involve medications that:

• Contain opioids, or
• Impact the liver

Opioid medicines (critical)

• Opioid pain medicines (e.g., oxycodone, morphine, codeine, fentanyl) may be blocked by naltrexone.
• In some cases this can lead to inadequate pain relief.
• Attempting to overcome opioid blockade by taking extra opioid doses can be dangerous.

If you need pain control (including before surgery or dental procedures), tell healthcare providers that you take Revia. They may need to use non-opioid pain strategies or carefully plan management.

Other medicines

• Some medicines may affect liver enzymes or liver function. Your pharmacist can check for potential interactions.
• Always provide a full list of medications, supplements and herbal products.

Safety profile: what to expect

Like all medicines, Revia can cause side effects. Many people experience mild, temporary effects—especially in the first days to weeks. However, some symptoms may require urgent attention.

Common side effects (often mild to moderate)

• Nausea
• Headache
• Dizziness or tiredness
• Fatigue
• Sleep disturbances
• Decreased appetite

Possible changes in mood or behaviour

• Some people report anxiety, irritability or changes in mood.

Liver-related risks (important)

Naltrexone can affect the liver, particularly at higher doses or in people who already have liver disease or continue heavy alcohol use.

Seek medical advice promptly if you develop:

• Yellowing of the skin or eyes (jaundice)
• Dark urine
• Severe or persistent abdominal pain (especially upper right side)
• Unexplained severe fatigue

Clinicians often arrange liver function tests before and during treatment for those at risk.

Opioid withdrawal risk

If opioids are still present in the body, taking naltrexone can trigger precipitated withdrawal. Symptoms may include sweating, nausea, diarrhoea, muscle aches, agitation, and strong cravings. This is another key reason why a careful start plan is essential for people previously using opioids.

Practical use tips for success

Revia works best when combined with a structured plan. Here are practical steps that many people find helpful:

• Start with a clear plan: especially if you’re moving from opioid use to naltrexone.
• Take it daily: consistency supports ongoing protection against relapse triggers.
• Track triggers: note times, places, feelings, or situations associated with cravings.
• Use support alongside medication: counselling, peer support, and behavioural strategies improve outcomes.
• Plan for pain care: carry a medication list or note that you take Revia in case you need urgent care.
• Monitor alcohol intake: avoid heavy drinking and seek support if drinking increases.
• Don’t “test” opioid blockade: it can lead to overdose risk if opioids are taken in larger amounts, especially when naltrexone levels fluctuate.

What if you need emergency treatment?

If you or someone else develops severe symptoms (e.g., unconsciousness, breathing problems, suspected overdose), call emergency services immediately (000 in Australia).

For emergency staff, it’s helpful to know:

• You take naltrexone (Revia)
• When your last dose was taken
• Any substances involved and timing

Alternative options

If Revia isn’t suitable, other approaches may be considered depending on your situation. Options can include:

For alcohol dependence

• Psychosocial support (e.g., cognitive behavioural therapy, motivational interviewing, relapse prevention planning)
• Other approved medications used in alcohol dependence (your clinician can advise what fits your health profile)
• Support services through alcohol and drug counselling programs

For opioid dependence

• Medication-assisted treatment such as opioid agonist therapy (as appropriate for the individual)
• Psychosocial interventions and structured relapse prevention
• Specialist care through drug and alcohol services

Choice depends on medical history, goals (abstinence vs harm reduction), liver function, previous treatment response, and access to support.

Market and legal context for Australia

In Australia, medicines are regulated through the Therapeutic Goods Administration (TGA). Availability, prescribing requirements, and subsidisation can vary depending on product and circumstances.

For opioid- and alcohol-related treatment, clinicians often consider evidence-based guidelines and local service models. Availability may also depend on supply routes and pharmacy stock.

Consumer medicines information (CMI) is available for authorised products and should be consulted for the most accurate safety and usage details relevant to your specific supply.

Recent guidance and clinical updates (what matters to patients)

Clinical practice continues to emphasise:

• Careful opioid-free assessment before starting naltrexone for opioid relapse prevention
• Liver monitoring—particularly for people with liver disease or ongoing heavy alcohol use
• Shared decision-making: matching treatment choice to individual goals and risk factors
• Integrated care: medication combined with counselling and structured relapse prevention

Because guidance may evolve, your pharmacist or healthcare professional can confirm the most up-to-date advice based on Australian practice.

Delivery and availability (online pharmacy guidance)

Revia availability may vary by region and stock levels. When ordering online in Australia, typical options include:

• Home delivery (timing depends on location and courier schedules)
• Standard or express shipping if offered by the online pharmacy
• Package tracking so you can monitor progress

What to expect: packaging is usually tamper-evident and labelled with dosing and batch/expiry details. If you’re ordering for the first time, allow time for verification and processing.

If you need Revia urgently (for example, because your next dose is due), it’s best to plan ahead and order early. If you miss doses, speak with a pharmacist for advice on restarting safely.

Safety: when to seek urgent advice

Get medical help urgently if you experience:

• Signs of an allergic reaction (swelling of face/lips, rash, difficulty breathing)
• Yellow skin/eyes, dark urine, severe upper abdominal pain, persistent vomiting
• Symptoms of severe opioid withdrawal after starting naltrexone
• Suicidal thoughts or severe mood changes (seek immediate help)

FAQ about Revia (naltrexone)

1) What is Revia used for?

Revia (naltrexone) is used in treatment plans for alcohol dependence to reduce relapse risk for some people, and in opioid dependence to help prevent relapse by blocking opioid effects once opioids are no longer present.

2) How quickly does it start working?

After taking an oral tablet, blood levels rise within hours and opioid blockade can begin soon after absorption. For alcohol dependence, benefits are typically assessed over weeks as part of an overall treatment plan.

3) Can I drink alcohol while taking Revia?

Revia may reduce the rewarding effects of alcohol for some people, but it does not make alcohol risk-free. Avoid heavy or unsafe drinking, and seek support if drinking increases or cravings become difficult.

4) Will naltrexone block pain relief from opioids?

Yes. If you take opioid pain medicines while on naltrexone, their effects may be reduced or blocked. If you need pain relief, tell clinicians that you take Revia so they can plan alternatives.

5) What happens if I take opioids while on Revia?

Opioid effects may be blocked, but attempting to override the blockade by taking more opioids can be dangerous and increase overdose risk—especially if the blockade lessens. Do not attempt to “test” or override naltrexone.

6) Can I stop Revia suddenly?

Stopping may reduce relapse protection and may increase cravings in some people. If you’re thinking of stopping, talk to your healthcare professional first to discuss a safe plan.

7) Do I need liver function tests?

They are often considered, especially if you have liver disease or ongoing heavy alcohol use. Your pharmacist or doctor can explain what monitoring is recommended for your situation.

8) Is it safe with other medicines?

Many medicines can be taken with naltrexone, but opioid-containing medicines and some liver-metabolised medicines require extra caution. Provide your complete medicine list to your pharmacist for a safety check.

9) What should I do if I miss a dose?

Take it when you remember if it’s not too close to your next dose. Don’t double up. If you’re unsure, ask your pharmacist, especially if you’ve missed multiple doses or you’re using naltrexone for opioid relapse prevention.

10) How is Revia different from “opioid-blocking” treatments for everyone?

Naltrexone is specifically an opioid receptor antagonist. Treatment choice depends on whether the primary goal is alcohol dependence relapse prevention or opioid relapse prevention, your opioid-free status, and your overall health.

Key takeaways

• Revia (naltrexone) helps support treatment plans for alcohol dependence and opioid relapse prevention.
• It blocks opioid receptors, so it’s essential to be opioid-free before starting for opioid relapse prevention.
• Liver health monitoring may be important, particularly for those with liver disease or ongoing heavy alcohol use.
• It may reduce the reward from alcohol and opioids, but it doesn’t eliminate all risks.
• For best results, combine medication with counselling, relapse prevention strategies, and ongoing support.

Need help choosing a plan or managing side effects? You can speak with a pharmacist or healthcare professional for personalised advice based on your medical history and substance use goals.