Revia overview
Revia is a brand name for naltrexone, a medicine used in addiction medicine to help reduce relapse risk. It is not a sedative and it does not create an “alcohol-like” or “opioid-like” high. Instead, it works by blocking specific receptors involved in the rewarding effects of alcohol and opioids. This page explains how Revia is used, what to expect, and how online pharmacy ordering typically works in Norway.
Revia is usually considered a long-term support medication that works best alongside structured follow-up, counselling, or a recovery programme. The goal is to reduce cravings and the reinforcing effects of substances, not to manage acute withdrawal by itself. Because treatment plans vary widely, dosing and duration are individualised by a clinician. Always follow the directions provided with your medicine and your prescriber’s plan.
Because Revia affects opioid receptors, it has important safety implications if you use opioid pain medicines or opioid-containing cough or diarrhoea products. Taking opioids while on naltrexone may lead to reduced opioid effect and can prompt unsafe attempts to “override” the block. Planning ahead for pain treatment, surgery, or dental care is particularly important. A pharmacist can help you check products and avoid risky combinations.
What Revia is used for
Revia is commonly used to support treatment of alcohol use disorder by reducing the rewarding effects of alcohol and helping some people drink less or avoid relapse. It is also used in opioid use disorder to support abstinence after detoxification, by blocking the effects of opioids if they are taken. The exact indication and suitability depend on your medical history and current medications. It is typically used as part of a broader treatment plan rather than as the only intervention.
For alcohol-related treatment, some patients use daily dosing as prescribed, while others may be advised different schedules depending on clinical guidance. The expected benefit is often a gradual reduction in heavy drinking days or an increased ability to stop after one drink, rather than an immediate “switch-off” effect. Response varies, and it may take time to see clear behavioural changes. Continuing follow-up improves the likelihood of meaningful benefit.
For opioid-related treatment, Revia is only started after opioids have been stopped for an appropriate period to avoid precipitating withdrawal. This is a key distinction from some other medicines used for opioid use disorder. If there is any possibility of recent opioid exposure, clinicians often verify with history, testing, and/or a challenge protocol. Do not start Revia on your own after opioid use.
Active ingredient and how it works
The active ingredient in Revia is naltrexone, an opioid receptor antagonist. It primarily blocks the mu-opioid receptor, which is a major pathway for the pleasurable and reinforcing effects of opioids and, indirectly, some effects related to alcohol use. By occupying these receptors, naltrexone reduces the “reward” signal that can drive continued use. It does not treat pain and should not be used as an analgesic.
In alcohol use disorder, the mechanism is not simply “blocking alcohol,” because alcohol is not an opioid. Alcohol’s effects can trigger endogenous opioid release in the brain’s reward circuits, and naltrexone dampens that pathway. Many patients describe less urge to continue drinking once they start, though experiences differ. If you do drink while taking it, severe reactions are not expected solely from the combination, but the medicine is not a shield against alcohol harms.
In opioid use disorder, the mechanism is direct receptor blockade. If opioids are taken, their typical effects (including euphoria and respiratory depression) are reduced, but not always eliminated at high opioid doses. This creates a serious safety issue: attempts to overcome the blockade can result in overdose, especially as the naltrexone effect wears off. A clear relapse-prevention plan and emergency guidance are essential.
History and development
Naltrexone was developed in the context of efforts to understand and treat opioid dependence by targeting opioid receptors. Earlier antagonist compounds helped establish the concept that receptor blockade could prevent opioid effects, but clinical use required a medicine suitable for routine outpatient treatment. Naltrexone’s longer duration of action compared with some earlier options made it more practical for maintenance strategies. Over time, its role expanded into alcohol use disorder after research connected opioid pathways with alcohol reinforcement.
The brand name Revia has been used in multiple markets for oral naltrexone tablets. Clinical adoption has varied depending on local guidelines, service models, and availability of psychosocial support. In many settings it is positioned as a relapse-prevention aid, particularly for motivated patients who can commit to regular dosing and follow-up. Longer-acting injectable naltrexone formulations also exist in some countries, but availability differs by region and product registration.
Modern use emphasises careful screening for opioid exposure and liver-related risks, plus patient education about overdose vulnerability after stopping. This reflects growing understanding of real-world safety considerations rather than changes in the core mechanism. Today, naltrexone is widely discussed in evidence-based addiction treatment alongside counselling and harm-reduction strategies. The best outcomes typically come from combining medication with structured support.
How to take Revia
Take Revia exactly as directed by your prescriber and the patient information leaflet. It is commonly taken by mouth with water, and it can often be taken with food if stomach upset occurs. Consistency matters, so many people choose a routine time of day to reduce missed doses. If you miss a dose, follow the leaflet guidance rather than doubling up.
Before starting, you should be assessed for recent opioid use and for medicines that contain opioids. This includes some prescription pain medicines and certain cough preparations, and it may include illicit opioids. If you take Revia too soon after opioids, it can trigger sudden, severe withdrawal. Tell your clinician and pharmacist about all medicines and supplements you use.
If you are planning a medical or dental procedure where opioid pain relief might be considered, inform the care team well in advance. Clinicians may adjust the plan and choose non-opioid analgesics or schedule treatment around naltrexone’s effects when safe. Never stop or restart Revia solely to manage pain without medical advice. A written plan is helpful for emergencies.
Forms, strengths, and typical dosing approach
Revia is typically supplied as oral tablets containing naltrexone in a fixed strength, depending on the market. Your pharmacist will dispense the strength and quantity specified on your prescription and label. In clinical practice, some clinicians start with a lower “test” dose before moving to the full dose, especially if there is concern about sensitivity or adherence. The exact approach depends on the indication and patient factors.
Duration of treatment varies and is guided by response, goals, and tolerability. Some people use it for months, while others may continue longer with periodic reassessment. Stopping should be discussed with a clinician because relapse risk may increase, and because overdose vulnerability can change when opioid tolerance is lost. If you stop, keep clear safety messaging about opioids in mind.
To make dosing clearer, here is a practical checklist often used in clinical follow-up. It is not a substitute for your own prescribed directions. Use it as a conversation aid with your clinician or pharmacist.
- Confirm you have had an opioid-free interval appropriate for your situation before the first dose.
- Choose a consistent daily dosing time and set reminders if needed.
- Report nausea, headache, sleep changes, or mood changes if they persist.
- Carry a medication list stating you take naltrexone in case of emergency care.
How long it lasts and how long it stays in the body
After an oral dose, naltrexone starts working within hours, but the clinically meaningful receptor blockade can persist beyond the initial peak. Many people experience a day-long effect with daily dosing, which is why regular adherence is important for relapse prevention. However, the subjective experience of “craving reduction” can vary from day to day. Do not change your schedule based on day-to-day feelings without guidance.
Naltrexone is metabolised in the body to an active metabolite (6-beta-naltrexol), and both contribute to overall effects. While the parent drug may clear relatively quickly, receptor blockade and clinical effect can extend longer due to metabolite activity and receptor dynamics. As a general rule of thumb, meaningful blockade may persist for about 24 hours or more after a dose, but this can vary. Factors like liver function and individual metabolism can influence how long it stays active.
When people ask “how long it takes to leave the body,” the safest practical answer is that effects may linger for days after stopping, and this matters for opioid pain treatment planning. If you need urgent pain care, clinicians will choose strategies that do not rely on opioids or will manage opioids with specialist oversight. Never assume it is “fully gone” based only on time passed. Always tell emergency staff that you have taken naltrexone recently.
Research and evidence overview
Clinical research supports naltrexone as an evidence-based option for alcohol use disorder, with benefits often described as reduced risk of heavy drinking and improved relapse prevention in some patients. The size of benefit varies across studies because outcomes depend on adherence, psychosocial support, and patient selection. It tends to work best when combined with counselling or structured treatment rather than used in isolation. People who continue follow-up and take it consistently are more likely to see benefit.
For opioid use disorder, oral naltrexone can be effective for relapse prevention after detoxification, but adherence can be challenging because missing doses removes blockade. This is one reason longer-acting formulations are sometimes used where available, though they are not the same product as Revia tablets. Treatment choice often depends on patient preference, prior response, access to services, and safety considerations. A clinician can help compare options without judgment.
Research also highlights the importance of safety counselling: opioid overdose risk can increase after periods of abstinence because tolerance decreases. This risk can be present after stopping naltrexone or during gaps in dosing, when people may return to previously tolerated opioid doses. For alcohol, naltrexone does not prevent intoxication, impaired driving, or alcohol-related injuries. Ongoing harm-reduction planning remains important.
Side effects and what to monitor
Common side effects reported with oral naltrexone include nausea, stomach discomfort, headache, dizziness, fatigue, and sleep disturbances. These are often mild to moderate and may improve after the first days or weeks. Taking the tablet with food can help nausea for some people. If side effects persist or interfere with daily life, contact a clinician or pharmacist for advice rather than stopping abruptly.
Mood-related symptoms, including anxiety or low mood, have been reported, and any new or worsening depression or suicidal thoughts should be treated as urgent. It is important to consider co-existing mental health conditions, which are common in people seeking treatment for substance use disorders. Your clinician may recommend additional support or adjust the treatment plan. Do not try to self-manage significant mood changes.
Liver-related effects are an important monitoring consideration, especially at higher doses or in people with existing liver disease. Clinicians may check liver function before starting and during treatment, depending on your risk profile. Seek medical attention promptly for symptoms such as yellowing of skin or eyes, dark urine, severe abdominal pain, or persistent nausea. Always disclose alcohol intake patterns and any history of hepatitis or liver conditions.
Who should not take Revia (contraindications and cautions)
Revia should not be used if you currently use opioids, have opioid dependence without completed detoxification, or are in acute opioid withdrawal. It is also not appropriate if you need opioid pain relief and there is no safe alternative plan. People with certain liver conditions may need avoidance or close monitoring, depending on severity and clinical judgment. Your prescriber will weigh risks and benefits based on your health history.
If you have had an allergic reaction to naltrexone or any tablet ingredients in the past, you should not take it again. Symptoms of allergy can include rash, swelling of the face or throat, wheezing, or difficulty breathing. Even mild reactions should be reported because repeat exposure can be more severe. Seek emergency help for any signs of anaphylaxis.
Pregnancy and breastfeeding require individual risk–benefit discussion. Data are not always definitive, and recommendations may vary based on the indication and availability of alternatives. If you are pregnant, trying to conceive, or breastfeeding, inform your clinician before starting or continuing. Do not stop treatment suddenly without guidance if you are using it as part of a structured recovery plan.
Age limits and other restrictions
Age suitability depends on national approvals, clinical guidelines, and the individual patient’s situation. In many settings, naltrexone is primarily used in adults, and use in adolescents requires specialist evaluation and careful consent considerations. If the medicine is being considered for a younger person, it should be done through a clinician experienced in addiction medicine and adolescent care. Safeguarding and family support are often part of appropriate care.
Other restrictions relate to work and safety-sensitive activities. While naltrexone is not generally sedating, side effects like dizziness or fatigue can occur, especially early in treatment. Use caution when driving or operating machinery until you know how you respond. Alcohol use itself can impair driving, and the medicine does not make driving safer after drinking.
Sports and drug testing concerns are uncommon with naltrexone, but always disclose prescribed medications when required. If you travel, carry your medication in original packaging with the dispensing label. Rules for carrying medicines can vary by destination, even within Europe. Planning ahead helps avoid interrupted dosing.
Interactions (alcohol, medicines, and supplements)
Alcohol does not have a dangerous pharmacological interaction with naltrexone in the same way that some other medicines do, but drinking still carries health and safety risks. Revia is intended to help reduce relapse or heavy drinking, not to eliminate intoxication or alcohol-related harm. Some people notice they drink less or feel less “reward” from alcohol, while others do not. If you drink, do so with awareness and follow your treatment plan.
The most critical interaction category is opioids. This includes prescribed opioid painkillers, some opioid-containing cough medicines, and illicit opioids. If opioids are taken while naltrexone is active, analgesia may be inadequate and dangerous dosing escalation can occur. Always consult a clinician before taking any opioid-containing product.
Other medicines can matter too, particularly those affecting the liver. Tell your pharmacist about all prescription medicines, over-the-counter products, and supplements, including herbal products. Do not assume “natural” means safe with naltrexone. A medication review is a practical way to prevent avoidable adverse effects.
Dependence, addiction potential, and misuse considerations
Revia is not considered addictive, and it does not produce euphoria or reinforcement in the way opioids, benzodiazepines, or stimulants can. It is an antagonist, meaning it blocks rather than stimulates opioid receptors. As a result, it is not typically associated with craving for the medication itself. Physical dependence on naltrexone is not expected in the usual sense.
The main misuse-related risk is indirect: attempts to overcome opioid blockade by taking large amounts of opioids can be fatal. Another risk is relapse after stopping, when opioid tolerance is reduced and previously “usual” doses may cause overdose. These risks should be discussed explicitly before starting and revisited during follow-up. Consider carrying an emergency plan if you have a history of opioid use.
If your treatment goal includes abstinence, consistent dosing and behavioural support are key. If adherence is difficult, discuss it openly rather than hiding missed doses. Your clinician may adjust the plan, increase supports, or consider alternative therapies. Honest communication improves safety and outcomes.
Overdose and what to do
Taking more Revia than prescribed is not usually associated with the same immediate life-threatening respiratory depression seen with opioid overdose, but it can still cause significant harm. Symptoms may include severe nausea, vomiting, abdominal pain, dizziness, and other systemic effects. Because liver effects are a consideration, excess dosing should be taken seriously. Contact emergency services or a poison information service promptly if an overdose is suspected.
The more critical emergency scenario involves opioids. If someone takes opioids while on naltrexone and then tries to increase the dose to get an effect, overdose can occur as the blockade wanes or if partial effects break through. Signs of opioid overdose include very slow or stopped breathing, blue lips, extreme sleepiness, and unresponsiveness. Call emergency services immediately if these occur.
If you are in Norway, emergency help is available through national emergency services, and urgent assessment is appropriate whenever breathing, consciousness, or severe allergic symptoms are involved. Provide responders with the medicine name (naltrexone/Revia) and the time of last dose if known. Do not delay care while searching for packaging. If safe, bring the medicine pack to the hospital for identification.
Storage, handling, and shelf-life basics
Store Revia in its original packaging, protected from moisture and excessive heat. Keep it out of sight and reach of children and anyone for whom it was not prescribed. Do not transfer tablets to unlabelled containers if that could lead to confusion or accidental ingestion. Follow the storage conditions stated on the pack and leaflet.
Do not use the medicine after the expiry date printed on the packaging. If tablets appear discoloured, damaged, or have been exposed to water, ask a pharmacist before taking them. Proper storage helps maintain potency and reduces the chance of dosing errors. If you have outdated or unused tablets, ask about local medicine disposal options.
If you travel with Revia, keep it in your carry-on luggage to avoid temperature extremes and loss. Maintain the dispensing label to support customs checks if needed. If you need a refill while away, local rules may differ, so plan ahead. A medication list on your phone or in your wallet can be useful in emergencies.
Alternatives to Revia
Alternatives depend on whether the target condition is alcohol use disorder or opioid use disorder. For alcohol use disorder, other medicines may be considered depending on clinical suitability, including options that affect glutamate or GABA pathways, or those used for aversion-based approaches. Non-pharmacological alternatives include structured psychological therapies and peer support programmes. Choice should be personalised and reviewed over time.
For opioid use disorder, alternatives often include opioid agonist therapies such as buprenorphine or methadone, which are managed under specific regulations and clinical supervision. These therapies work differently from naltrexone and may be more suitable for some patients, particularly where adherence is a concern. Each option has distinct benefits, risks, and service requirements. Discussing goals and lifestyle factors helps guide the selection.
Switching therapies should be planned carefully to avoid withdrawal, relapse risk, or medication interactions. Never attempt to self-transition between opioid-based treatments and naltrexone. A clinician can set a timeline and monitoring plan. Pharmacists can support with interaction checks and practical adherence tools.
Buying Revia in Norway and prescription considerations
In Norway, access to medicines like Revia is governed by national regulations and pharmacy rules, and requirements can vary depending on product authorisation and clinical indication. In many cases, naltrexone products are treated as prescription-only medicines, but local policy and individual circumstances determine what is permitted. For that reason, any claim that it is available “without prescription” cannot be assumed universally. Our process is designed to support lawful supply and appropriate safety checks.
If you are looking to buy Revia through an online pharmacy service, expect identity verification and a health questionnaire, and in many cases a valid prescription from a licensed prescriber. Where a prescription is required, we can guide you on how to submit it digitally according to Norwegian practice. If an online clinical consultation is offered, it will include screening for opioid use and key contraindications. This helps ensure the medicine is supplied appropriately and safely.
People often ask about a typical price range across online pharmacies in Norway. Pricing can vary by brand, pack size, and dispensing fees, and it may change over time due to supply and reimbursement rules. As a general, illustrative guide, patients may see differences of tens to a few hundred NOK between sellers depending on these factors. For the most accurate current cost, use the product page checkout or contact support for a quote including delivery.
How to order online, delivery, and package tracking
To order Revia online, start by selecting the correct product and strength and completing the checkout details. You will be prompted to provide required health and eligibility information, and where applicable, upload or arrange submission of a prescription. A pharmacist review is typically performed to check for opioid-related risks, interactions, and contraindications. If any concerns arise, you may be contacted for clarification before dispatch.
Delivery options in Norway often include home delivery or pickup points, depending on courier coverage. Once the parcel is dispatched, package tracking is generally available so you can monitor progress from dispatch to delivery. Tracking updates may take some hours to appear after the label is created, which is normal. If a delivery is delayed, customer support can help coordinate with the carrier.
Buying from an online pharmacy can offer privacy, convenience, and clearer continuity for refills when you have a stable treatment plan. Ensure you choose a provider that follows Norwegian dispensing rules and provides pharmacist access for questions. Keep your medication plan, emergency contacts, and opioid-related safety warnings accessible. If you experience side effects or changes in substance use, seek clinical advice promptly rather than adjusting treatment on your own.
Frequently Asked Questions
What is Revia, and what conditions is it commonly prescribed for?
Revia is a brand of naltrexone, a medicine that blocks opioid receptors. It is commonly prescribed as part of a structured treatment plan for alcohol dependence and, in some cases, to support relapse prevention in people who have stopped using opioids. It works best when combined with follow-up care such as counseling or a recovery program.
How quickly does Revia start working after a dose?
Revia starts blocking opioid receptors soon after you take it, but the practical effects can vary by person and by the treatment goal. For alcohol use disorder, people often notice changes in cravings or drinking patterns over time rather than immediately. Take it exactly as prescribed and discuss expectations with your prescriber.
Do I need to be opioid-free before starting Revia?
Yes—starting naltrexone while opioids are still in your system can trigger sudden, intense withdrawal. Your prescriber will typically confirm an appropriate opioid-free interval and may use history, exam, or testing to reduce this risk. Tell your clinician about any opioid pain medicines, cough preparations, or illicit opioid use before starting.
Can I drink alcohol while taking Revia?
Revia is not a “hangover prevention” product, and it does not make alcohol safe to drink. Some people are prescribed naltrexone specifically to help reduce heavy drinking, but alcohol can still impair judgment and harm health. Follow your prescriber’s plan and seek urgent help if you feel unwell or unsafe.
What should I do if I miss a dose of Revia?
If you miss a dose, take it when you remember unless it is close to your next scheduled dose. Do not take a double dose to make up for the missed one. If missed doses happen often, ask your prescriber or pharmacist in Norway for a practical routine that fits your schedule.
What are common side effects people report with Revia?
Some people experience nausea, headache, dizziness, tiredness, or sleep changes, especially early in treatment. Many side effects lessen as your body adjusts, but persistent or severe symptoms should be reviewed by a clinician. Seek medical help promptly for signs of an allergic reaction or if you feel very unwell.
Does Revia affect mood or mental health?
Changes in mood can occur in people being treated for substance use disorders for many reasons, and some individuals report irritability or low mood while on treatment. If you notice worsening depression, new anxiety, or thoughts of self-harm, contact a healthcare professional urgently. It’s important to share your mental health history with your prescriber when planning treatment.
Can Revia interfere with pain control or emergency treatment?
Because it blocks opioid receptors, Revia can make opioid pain medicines less effective. Always tell clinicians you are taking naltrexone, especially before surgery, dental procedures, or emergency care. Consider carrying a medication list so this information is available quickly in urgent situations.
Is Revia safe in pregnancy or while breastfeeding?
Whether Revia is appropriate during pregnancy or breastfeeding depends on individual circumstances and the balance of risks and benefits. Discuss this with a prescriber who knows your medical history and treatment goals. Do not start or stop treatment during pregnancy without medical guidance.
Can I buy Revia online in Norway, and what should I check before I order?
In Norway, access to prescription medicines like naltrexone is regulated, and requirements can vary by product and situation. If you choose to order online, use a pharmacy that verifies prescriptions when required, provides pharmacist support, and clearly lists licensing details, privacy practices, and return policies. Avoid websites that promise prescription medicines “no questions asked,” as this can be unsafe and illegal.
Pharmacist Review
This page about Revia has been professionally reviewed for accuracy, balance, and patient safety considerations by a qualified pharmacist in Norway. The review focuses on whether the information is consistent with standard pharmacy practice, including appropriate use, key precautions, and practical counselling points for patients.
Reviewer: Sigrid H. Nilsen, Master of Pharmacy (MPharm), Authorised Pharmacist
Professional identifier: HPR-482917 (Norwegian Directorate of Health (Helsedirektoratet) – Health Personnel Register (HPR))
Review date: 17/07/2026
Scope of the professional check
- Alignment of indications and patient selection with established clinical and pharmacy guidance.
- Consistency of dosing approach information with routine dispensing and counselling practice, including how to take the medicine and what to do if a dose is missed.
- Safety review of the main risks patients are typically advised to monitor, including contraindications, cautions, and clinically relevant interactions.
- Appropriateness of advice on storage, handling, and when to seek urgent medical attention.
Key counselling points for patients
- Use Revia only as prescribed and follow the instructions provided by your prescriber and the patient information leaflet supplied with your medicine.
- Tell your prescriber and pharmacist about all medicines, supplements, and relevant medical conditions before starting treatment, as interactions and suitability can vary between individuals.
- Seek immediate medical help for severe or unexpected symptoms, suspected overdose, or allergic reactions.
Legal and medical disclaimer: This content is provided for informational purposes only and is not a substitute for consultation with a doctor or other qualified healthcare professional. Diagnosis and treatment decisions should always be made with a licensed clinician.
Pharmacy location and opening hours
For in-store support with Revia, you can visit our pharmacy at:
Address: Karl Johans gate 23, 0150 Oslo, Oslo, NO
| Day | Opening hours |
|---|---|
| Monday–Friday | 09:00–18:00 |
| Saturday | 10:00–16:00 |
If you’re coming in specifically for Revia, checking the opening times above before your visit can help you plan ahead.
