Revia (Naltrexone) — Patient Information (Australia)

Revia is a medicine that contains naltrexone. It is used to help support treatment goals in certain alcohol- and opioid-related conditions. This page explains how Revia works, how it is used, what to expect, important safety information, and practical tips for everyday use.

Note: Medicines affect people differently. Always follow the instructions given to you by your healthcare professional and read the consumer medicine information (CMI) provided with your product.

Quick facts

• Active ingredient: Naltrexone
• Brand: Revia
• Common forms: Oral tablets
• Typical purpose: Supports treatment for alcohol dependence and helps prevent relapse in people who have stopped opioid use
• How it works: Blocks opioid receptors and helps reduce the effects of alcohol/opioids

What is Revia (naltrexone)?

Revia is an oral opioid antagonist. Opioid antagonists block the effects of opioids by attaching to opioid receptors in the brain and other parts of the body. By doing this, naltrexone can help reduce opioid-related effects and can also support treatment plans for certain alcohol-related conditions.

In Australia, naltrexone is available via supply through pharmacies and is commonly used as part of a broader treatment approach that may include counselling, behavioural therapies, support services, and ongoing clinical review.

How Revia works (mechanism of action)

Naltrexone primarily acts by blocking opioid receptors—especially the mu (μ) opioid receptors. Opioids exert their effects (such as pain relief and feelings of euphoria) by stimulating these receptors. When naltrexone occupies the receptors, opioids are less able to bind and produce their effects.

For people with alcohol dependence, the exact way naltrexone supports outcomes is not fully explained by opioid receptor blockade alone, but it is thought that blocking opioid signalling can influence brain pathways involved in reward and reinforcement related to alcohol. For opioid dependence, blocking receptors reduces the likelihood of opioid effects if opioids are taken again.

• Opioid blockade: reduces or blocks the effects of opioid medicines and illicit opioids
• Support for alcohol dependence: may reduce heavy drinking and help with abstinence goals when used as part of treatment

Pharmacokinetics: how the body processes naltrexone

Pharmacokinetics describes how a drug moves through the body—how it is absorbed, transformed, and removed.

Because naltrexone is processed in the liver and eliminated by the kidneys, people with liver or kidney problems should discuss suitability and monitoring with a clinician.

Typical uses of Revia

Revia is used in specific situations. Your healthcare professional will confirm whether it is appropriate for you.

Common indications (general)

• Alcohol dependence: to support treatment goals such as reducing heavy drinking and maintaining abstinence, in combination with psychosocial support.
• Opioid dependence: to help prevent relapse in people who have discontinued opioids. It helps by blocking opioid effects.

Revia may be considered part of a broader plan that includes counselling and ongoing monitoring.

Dosing: how Revia is usually taken

Dosing can vary depending on the condition being treated and your individual situation. Always follow your clinician’s directions. The following describes typical dosing approaches used in practice and reflected in product guidance.

Typical oral dosing (general)

• Alcohol dependence: often starts with a daily dose (commonly once daily). Treatment may be planned for a set duration and reviewed regularly.
• Opioid dependence: naltrexone is generally used only after opioids have been stopped and withdrawal has resolved. This is important to avoid precipitated withdrawal.

Important timing note for opioid use

If you have used opioids recently, naltrexone may trigger withdrawal symptoms because it blocks opioid receptors. Clinicians typically assess opioid-free status before starting naltrexone. If you are unsure whether you may have opioids in your system, speak with your healthcare professional before starting.

Missed dose

• If you miss a dose, take it when you remember unless it is close to the time of your next dose.
• Do not double up doses to “catch up.”
• If you miss multiple doses, contact your clinician for advice.

When does Revia start working?

Some opioid-blocking effects may be present after taking a dose, but treatment benefits—particularly for alcohol dependence—may develop over time with consistent use and supportive therapy. The timeline differs person to person and depends on adherence and the overall treatment plan.

For opioid-related goals, Revia is intended to help reduce the rewarding effects of opioid use when taken regularly.

Food interactions: can you take Revia with meals?

For most people, naltrexone can be taken with or without food. Taking it with food may reduce the chance of stomach upset if you are sensitive to medications.

• Take with water and swallow the tablet whole.
• If nausea or stomach discomfort occurs, discuss strategies with your pharmacist (for example, taking with a meal).

Alcohol and medicine interactions

Alcohol while taking Revia

Revia is used in alcohol dependence treatment plans, so alcohol use may be a sensitive and clinically important issue. Even if alcohol effects are reduced for some people, alcohol can still cause harm (including accidents, liver strain, and interactions with other medicines).

• Do not use alcohol to test whether you are “blocked”—your response can vary.
• If you are drinking or at risk of relapse, seek support from your healthcare team.

Opioids and opioid-containing medicines

This is the most important interaction. Naltrexone blocks opioid receptors, so:

• Opioid pain relief (for example morphine, oxycodone, codeine, heroin) may become less effective.
• Attempting to overcome the blockage by taking opioids can be dangerous and may lead to unpredictable outcomes, including overdose if naltrexone levels change.
• If emergency pain management is needed, healthcare providers should be told you take naltrexone.

Other medicines

Several medicines can affect liver enzymes or drug metabolism. Always tell your pharmacist or doctor about all medicines you take, including:

• Prescription medicines
• Over-the-counter medicines
• Herbal products
• Supplements

If you are taking medicines that affect the liver, you should discuss your risk profile and whether monitoring (such as liver function tests) is needed.

Safety profile: who should be careful with Revia?

Common side effects

Many people experience mild or temporary effects when starting naltrexone. Report persistent or severe symptoms to a healthcare professional. Commonly reported side effects may include:

• Nausea or stomach discomfort
• Headache
• Dizziness
• Fatigue or sleep changes
• Reduced appetite
• Muscle aches

Serious risks (seek medical help urgently if needed)

• Withdrawal symptoms in people with recent opioid use (can include agitation, anxiety, sweating, nausea, diarrhoea, muscle cramps, and rapid heart rate).
• Liver injury: naltrexone can affect liver enzymes in some individuals. Seek prompt medical advice if you develop symptoms such as unusual tiredness, upper right abdominal pain, dark urine, or yellowing of the eyes/skin.
• Allergic reactions (e.g., rash, swelling of the face/lips, difficulty breathing).

Who should discuss naltrexone with a clinician before starting?

• People with liver disease or a history of significant liver problems
• People who have used opioids recently (including prescription opioids)
• People with kidney impairment (dose suitability may need review)
• Pregnant or breastfeeding individuals (risk/benefit discussion is needed)
• People taking medicines that may affect liver function

Practical tips for using Revia safely

1) Don’t start if opioid use was recent

If there is any chance you have used opioids in the timeframe relevant to your body, talk to your clinician first. Starting naltrexone too soon can cause significant withdrawal symptoms.

2) Keep a plan for cravings and triggers

Revia can support recovery, but medication is usually most effective when combined with psychosocial support. Consider:

• Identifying triggers (people, places, stress, emotions)
• Planning coping strategies (call a support person, attend counselling, use structured routines)
• Using supportive services available in Australia (GP, counselling, community services)

3) Tell healthcare providers you take naltrexone

If you need medical or dental treatment—especially pain relief—ensure clinicians know you take Revia. This helps avoid ineffective opioid analgesia and helps guide safe alternatives.

4) Alcohol and “testing” are not safe

Avoid trying to see how alcohol or opioids affect you while on naltrexone. Your response can be unpredictable and may not protect you from harm.

5) Consider monitoring if advised

If you have liver risk factors, clinicians may recommend periodic blood tests. Follow the monitoring schedule they provide.

Alternative options

Treatment for alcohol dependence and opioid dependence is individualised. Depending on your needs, healthcare professionals may consider alternatives such as:

For alcohol dependence

• Acamprosate (helps maintain abstinence for some people)
• Disulfiram (causes unpleasant reactions with alcohol—suitable only for selected patients and requires strict adherence)
• Behavioural therapies and support programs (often core components)

For opioid dependence

• Opioid agonist therapy (commonly methadone or buprenorphine-containing treatments where appropriate)
• Non-pharmacological supports such as counselling, harm-reduction services, and psychosocial programs

Ask your clinician what options are suitable for your situation and how they compare in benefits, monitoring needs, and risks.

Revia in the Australian market: practical legal and guidance context

In Australia, medicines are supplied in line with national medicines regulation and state/territory requirements. Many medicines used for substance dependence require careful clinical assessment and follow-up.

For naltrexone-containing products, clinicians generally focus on:

• Confirming diagnosis and treatment goals
• Checking for opioid-free status before starting (to reduce withdrawal risk)
• Assessing liver health and medicine history
• Providing education about opioid blockade and pain management planning

Recent guidance (what to consider)

Across substance-use treatment services, ongoing principles emphasise:

• Medication should be combined with psychosocial support where possible
• Close follow-up during initiation and dose changes
• Clear safety planning regarding opioid use and emergency analgesia
• Regular review of effectiveness and side effects

Your healthcare team may align local practice with updates from Australian health authorities and clinical guidelines. Because recommendations can evolve, ask your clinician or pharmacist what current guidance applies to you.

Delivery and availability

Revia availability can vary depending on supply and prescribing/supply requirements. When ordering online in Australia, allow time for dispensing and dispatch.

• Dispatch times: typically depend on pharmacy stock and verification processes
• Delivery: standard courier delivery or express options may be offered
• Cold chain: usually not required for tablet formulations

If you have time-critical needs (for example, starting a new treatment plan), contact customer support or check estimated delivery at checkout.

FAQ

1) Can I take Revia if I still have opioid medicines in my system?

It depends on timing and the type of opioid. Starting naltrexone too soon after opioid use can trigger withdrawal symptoms. Discuss your situation with your clinician before starting.

2) Will naltrexone stop me from feeling the effects of opioids completely?

Naltrexone blocks opioid receptors, but individual responses vary. Do not rely on it to “safe-proof” opioid use. It can also reduce effectiveness of prescribed opioid pain relief.

3) How long do I need to take Revia?

Treatment length varies based on your goals (for example, maintaining abstinence) and your response. Regular review with your clinician is important to determine the best duration.

4) Can I drive or operate machinery after taking Revia?

Some people experience dizziness or fatigue. If you feel unwell or drowsy, avoid driving and operating machinery until you know how the medicine affects you.

5) Are there food restrictions?

Usually, you can take Revia with or without food. If nausea occurs, taking it with a meal may help.

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

Take it when you remember unless it’s near the next dose. Do not double up. If you miss several doses, contact your healthcare provider for advice.

7) What if I need surgery or dental pain relief?

Tell your dentist/surgeon and anaesthetist that you take naltrexone. Pain management plans may need adjustment because opioid analgesics may not work as expected.

8) Does Revia interact with alcohol?

Revia is used for alcohol dependence, but drinking alcohol can still cause harm. Avoid “testing” effects and seek support if you are at risk of relapse.

9) Can Revia be used alongside counselling or support programs?

Yes. Many treatment models for alcohol and opioid dependence combine medication with counselling and psychosocial support. This combination often improves outcomes.

10) What symptoms would suggest I should get medical help?

Seek urgent medical advice if you develop signs of allergic reaction, severe or worsening symptoms, significant nausea/vomiting with dehydration, symptoms of liver problems (such as yellowing eyes/skin, dark urine, severe fatigue), or signs of withdrawal after recent opioid use.

Important note

This information is intended to help you understand Revia (naltrexone) and how it may fit into your treatment. It does not replace advice from your healthcare professional. If you have questions about your suitability, dosing timing, or interactions with your current medicines, speak with a clinician or pharmacist.