Overview of Revia
Revia is a brand name for naltrexone, a prescription medication used in addiction medicine to support recovery. It is not an opioid and it does not create a “high,” but it can change how the body responds to opioids and alcohol. In Canada, naltrexone is typically used as part of a broader treatment plan that includes counselling, follow-up, and relapse-prevention strategies. This page explains how Revia works, how it is taken, and what to consider before starting it.
Revia is best understood as a medication that helps reduce the reinforcing effects of substances, which can make it easier to stay on track with recovery goals. It does not treat acute withdrawal on its own and is not an emergency medication. Most people take it on a regular schedule, and consistent use is important for benefit. Decisions about starting or continuing Revia should be individualized and guided by a qualified clinician.
Because Revia affects opioid receptors, it has unique safety considerations, especially for anyone using opioid pain medicines or illicit opioids. It can also interact with certain liver conditions and requires attention to symptoms that could suggest liver stress. If you are unsure whether Revia is appropriate for you, a pharmacist or prescriber can review your history and medications. The information below is educational and intended to support informed, safe use.
What Revia Is Used For
Revia (naltrexone) is commonly used to help maintain abstinence in opioid use disorder after a person has fully stopped opioids. It can also be used to help reduce alcohol cravings or the rewarding effects of drinking in alcohol use disorder. The goal is to support recovery by lowering relapse risk and reducing the pull to return to use. It is usually combined with behavioural supports rather than used alone.
For opioid use disorder, Revia is generally started only after an adequate opioid-free period to avoid triggering sudden withdrawal. For alcohol use disorder, it may be started while a person is abstinent or, in some care plans, when the person is still drinking but working toward reduction. The right approach depends on medical history, goals, and monitoring. A clinician can help decide the timing and whether oral naltrexone is suitable.
Revia is not a treatment for pain and will block the effects of opioid pain medications. If opioid pain control is needed for surgery or injury, clinicians must plan ahead because standard opioid doses may be less effective. This is one reason it is important to carry an updated medication list and inform all care providers. If you have chronic pain, discuss alternatives and a contingency plan before taking Revia.
Active Ingredient and How It Relates to Other Names
The active ingredient in Revia is naltrexone hydrochloride. You may see it described simply as “naltrexone” on labels, prescriptions, or medication profiles. Different manufacturers can supply naltrexone tablets under various brand names or as a generic product. The clinical effect is determined by the active ingredient and dose, not by the brand.
Naltrexone is part of a group of medications called opioid antagonists. These medications bind to opioid receptors without activating them, which blocks opioids from producing their typical effects. This receptor activity also influences reward pathways involved in alcohol use disorder. If you have previously taken naloxone (an emergency opioid overdose antidote), note that it is a different medication with a different purpose and duration, even though both interact with opioid receptors.
When comparing products, pay attention to tablet strength, excipients (inactive ingredients), and any special dispensing notes. People with sensitivities to certain dyes or fillers may need a specific manufacturer. Your pharmacist can confirm whether a product is bioequivalent and appropriate to substitute. Always verify that the medication is naltrexone before starting, especially if switching pharmacies.
Origin and Development History
Naltrexone was developed after earlier opioid antagonists showed that blocking opioid receptors could reverse or prevent opioid effects. Researchers sought an option with longer activity than short-acting antagonists used in emergencies. Over time, naltrexone became part of clinical approaches to relapse prevention, particularly for people who had already achieved opioid abstinence. Its role expanded as evidence grew for alcohol use disorder as well.
The medication’s history also reflects the evolution of addiction treatment from a purely abstinence-based lens to a chronic-care model that uses medications to support sustained recovery. Naltrexone’s non-intoxicating profile helped it fit into care plans where avoiding sedation and impairment is important. Clinical practice has continued to refine who benefits most, how to support adherence, and how to combine medication with psychosocial care. These refinements matter because outcomes often depend on the whole treatment program rather than a single pill.
In modern use, naltrexone is one option among several evidence-based medications for substance use disorders. It is particularly relevant for people who want an opioid-free maintenance strategy or who are seeking support to reduce heavy drinking. Ongoing research continues to explore predictors of response and the best follow-up strategies. As with many medications, real-world success depends on careful selection, monitoring, and patient preference.
Mechanism of Action (How Revia Works)
Revia works primarily by blocking mu-opioid receptors in the brain and body. When these receptors are blocked, opioids such as morphine, oxycodone, or heroin have reduced or no effect. This can help reduce the incentive to return to opioid use because the expected “reward” is diminished. The blockade is pharmacologic, meaning it depends on taking the medication consistently.
For alcohol use disorder, the mechanism is more indirect but still related to reward circuitry. Alcohol can influence endogenous opioid signalling, and blocking opioid receptors may reduce the pleasurable or reinforcing effects of drinking for some people. As a result, many patients report fewer cravings or less satisfaction from alcohol. Response varies, and structured follow-up helps determine whether the medication is meeting goals.
Because Revia blocks opioid receptors, it can also block opioid-based cough syrups and some antidiarrheal medications with opioid activity. It does not block non-opioid pain relievers such as acetaminophen or ibuprofen. If you are unsure whether a product contains an opioid, ask a pharmacist before using it. This check is especially important for combination products and older prescriptions.
How to Take Revia Safely
Revia is taken by mouth as a tablet, usually once daily, exactly as directed by a prescriber. Some clinicians use alternate dosing schedules in select cases, but those plans should be followed precisely because missed doses can reduce receptor blockade. Taking it with food can help reduce stomach upset for some people. Do not change the dose or schedule without medical guidance.
Before starting Revia for opioid use disorder, you must be opioid-free for a period determined by your clinician to reduce the risk of precipitated withdrawal. Starting too soon after opioid use can cause sudden and severe withdrawal symptoms. If there is uncertainty about opioid abstinence, clinicians may use history, urine testing, or a supervised challenge approach based on local practice. Never try to “test” whether Revia will cause withdrawal on your own.
If you miss a dose, follow your prescriber’s instructions or the pharmacy label guidance. Do not double up doses to “catch up” unless you have been specifically advised to do so. If you stop Revia, your tolerance to opioids may be lower than before, which increases overdose risk if you return to opioid use. This is a critical safety point to discuss during follow-up visits.
Available Forms and Common Dosages
Revia is most commonly available as oral tablets of naltrexone. In many settings, naltrexone tablets are supplied in a standard strength, and dosing is individualized according to the condition being treated, tolerability, and adherence considerations. Your prescription label will specify the exact strength and instructions. If you receive a generic product, the strength should match the prescription.
Some people may start with a lower initial dose to assess tolerability, especially if nausea or headache is a concern. Dose adjustments should be made by a clinician who understands your substance use history and medical status. Liver function may be assessed before and during treatment depending on risk factors. This monitoring is part of safe use and not a sign that problems are expected.
There is also a long-acting injectable naltrexone formulation in some markets, which is different from Revia tablets. If adherence to daily tablets is difficult, ask a clinician about whether an extended-release option is available and appropriate in Canada. Availability and coverage can vary by province and insurer. Do not assume interchangeability without professional advice.
How Long Revia Takes to Work and How Long Effects Last
After an oral dose, Revia begins to block opioid receptors within hours, but the clinical experience can differ depending on the goal. For opioid blockade, the effect is tied to receptor occupancy and is strongest when doses are taken consistently. For alcohol use disorder, changes in cravings or drinking patterns may emerge over days to weeks, especially when paired with counselling. Tracking cravings and drinking can help determine whether the medication is helping.
The opioid-blocking effect of a single tablet can last beyond the time you “feel” anything, because Revia does not cause sedation or noticeable effects in many people. Even if you do not notice a sensation, receptor blockade may still be present. This is why attempting to override the blockade by taking opioids is dangerous. High doses of opioids can lead to overdose once the blockade is incomplete or wears off.
If you anticipate surgery, dental work, or emergency pain treatment, notify the treating team that you are taking naltrexone. Managing pain may require non-opioid approaches or specialized planning. Do not stop Revia on your own to “allow opioids to work,” because stopping creates other risks and requires individualized timing. Coordination between prescriber, surgeon/dentist, and pharmacist is the safest approach.
How Long Revia Stays in the Body
Revia and its active metabolite are cleared over time through metabolism and excretion. Practically, this means the opioid receptor blockade can persist for a period after the last dose, and the exact duration varies by person. Factors such as liver function, adherence pattern, and individual metabolism can influence how long meaningful effects remain. Because of this variability, only a clinician can advise on timing for planned opioid use in medical settings.
For most patients, the medication does not “build up” indefinitely when taken as directed. However, consistency matters, and intermittent use may lead to unpredictable blockade levels. If you stop and restart, discuss it with your clinician to reduce safety risks. This is especially important if there has been any opioid exposure while off the medication.
Drug testing and medication timing are separate issues: naltrexone presence on a test depends on the specific assay used. Revia is not an opioid and is not expected to cause a positive opioid screen on standard panels. Still, testing protocols differ, and you can ask the testing site what substances are included. Share your prescription information if questions arise.
Scientific Evidence and What Research Generally Shows
Clinical research supports naltrexone as an evidence-based option for alcohol use disorder and for relapse prevention in opioid use disorder when started after detoxification. Studies generally evaluate outcomes such as reduced heavy drinking days, lower relapse rates, and improved treatment retention when medication is paired with psychosocial support. The magnitude of benefit varies, and not everyone responds the same way. This is normal in addiction medicine, where multiple effective options exist.
Research also highlights that adherence is a key predictor of benefit with oral naltrexone. People who have support for routine dosing and follow-up often do better than those who take it inconsistently. For some patients, long-acting formulations may help with adherence, where available. Your clinician can help match the option to your preferences and circumstances.
Importantly, naltrexone is not considered a stand-alone cure. The most durable outcomes usually involve combined approaches such as counselling, peer support, and addressing co-occurring mental health conditions. If you are managing anxiety, depression, or trauma, integrated care can improve results. A pharmacist can also help by reviewing interactions and simplifying medication routines.
Dependence, Misuse, and Addiction Potential
Revia is not considered addictive and does not produce euphoria. It does not cause physical dependence in the way opioids, benzodiazepines, or alcohol can. People generally do not develop cravings for naltrexone itself. For these reasons, it is not typically associated with misuse.
That said, stopping Revia can carry indirect risk because opioid tolerance may be reduced after a period of abstinence. If a person returns to opioid use, the dose that previously felt “normal” may become dangerous. This overdose risk is a key counselling point and one reason ongoing support matters. If relapse risk is high, talk with your care team about naloxone access and a safety plan.
If you feel increased cravings, worsening mood, or thoughts of self-harm while taking Revia, seek medical support promptly. These symptoms may not be caused by the medication, but they should always be taken seriously. Addiction treatment often requires adjustments over time. Your clinician can reassess the plan and consider alternatives if needed.
Side Effects and What to Watch For
Common side effects reported with naltrexone include nausea, stomach discomfort, headache, dizziness, fatigue, and sleep changes. Many of these are mild to moderate and may improve after the first days to weeks. Taking the tablet with food and staying hydrated can help with gastrointestinal effects. If side effects persist or interfere with daily function, consult your prescriber.
Because naltrexone is processed by the liver, clinicians may be cautious in people with active liver disease. Seek urgent medical attention if you develop symptoms that could suggest liver problems, such as persistent upper abdominal pain, severe nausea, dark urine, or yellowing of the skin or eyes. These symptoms have many possible causes, but they require prompt evaluation. Do not ignore them or attempt to self-treat.
Some people notice increased anxiety, restlessness, or changes in mood. If you have a history of depression or other mental health conditions, proactive monitoring is sensible. Keep a brief log of symptoms, sleep, and cravings to discuss at follow-up visits. This information can help your clinician decide whether to continue, adjust, or change therapy.
Who Should Not Take Revia and Key Restrictions
Revia should not be used by anyone who is currently taking opioid medications or using illicit opioids, because it can block opioid effects and may trigger acute withdrawal if opioids are still in the system. It is also generally avoided in people with acute hepatitis or severe liver impairment unless a specialist determines benefits outweigh risks. People with a known hypersensitivity to naltrexone or any tablet component should not take it. Always disclose your full medication and substance use history before starting.
A critical restriction is that you should not attempt to overcome Revia’s opioid blockade by taking more opioids. This behaviour can lead to life-threatening overdose, particularly as the blockade wanes. If you anticipate needing opioid pain control, your care team must plan an approach that may involve temporarily stopping naltrexone under supervision and using alternative pain strategies. Emergency departments can manage pain in patients on naltrexone, but they need to know about it.
Pregnancy and breastfeeding decisions are individualized and should involve a clinician experienced in perinatal care and substance use treatment. If you are pregnant, planning pregnancy, or breastfeeding, discuss the risks and benefits before starting or continuing Revia. Do not stop medication abruptly without a plan, especially if it supports abstinence. Shared decision-making is essential in this setting.
Age Limits and Use in Younger or Older Adults
Age eligibility depends on the indication, clinical context, and product authorization in Canada. In general, use in adolescents requires specialist oversight, careful assessment, and involvement of guardians as appropriate. If Revia is considered for a younger patient, clinicians weigh maturity, comorbidities, and the ability to adhere to treatment. Monitoring and supportive services are particularly important in this group.
For older adults, naltrexone may still be used, but clinicians consider liver function, other medications, and fall risk if dizziness occurs. Older patients are more likely to take multiple medications, increasing the importance of a pharmacy interaction check. Dose selection and follow-up may be more cautious. Reporting new symptoms early helps prevent complications.
No matter the age, Revia is only one part of care. Treatment plans that include behavioural support, family involvement when appropriate, and follow-up appointments tend to be more effective. If age-related consent or privacy questions arise, Canadian provincial rules and clinic policies may apply. A pharmacist can explain what information is needed for safe dispensing.
Allergic Reactions and When to Seek Help
Allergic reactions to Revia are uncommon but possible. Symptoms can include hives, itching, swelling of the face or tongue, wheezing, or difficulty breathing. These symptoms require urgent medical attention, as they may represent a severe reaction. Do not take another dose if you suspect an allergy.
Some reactions are non-allergic but still important, such as severe rash, blistering, or fever with skin symptoms. Because it can be difficult to distinguish allergy from other causes, it is safest to seek assessment promptly. Bring the medication package or a photo of the label if possible. This helps clinicians identify the product and any inactive ingredients.
If you have had allergic reactions to medications in the past, tell your pharmacist. In some cases, a different manufacturer’s generic tablet may be better tolerated due to different excipients. Never attempt to “desensitize” yourself by taking small amounts without medical supervision. Safety should come first.
Interactions, Including Alcohol and Other Medicines
Revia’s most important interactions involve opioids. It will block opioid analgesics and opioid-containing cough or diarrhea medicines, which can lead to inadequate symptom control or unsafe attempts to increase opioid doses. Tell every prescriber and pharmacist that you take naltrexone before accepting new prescriptions. If you use over-the-counter products, ask specifically whether they contain an opioid.
With alcohol, naltrexone does not create a dangerous “disulfiram-like” reaction. However, drinking can still impair judgment, worsen mental health symptoms, and increase accident risk, even if cravings are reduced. If your care plan includes reducing or stopping alcohol, your clinician can suggest practical supports. Avoid driving or safety-sensitive work if alcohol use has occurred.
Other interactions may involve medications that affect the liver or that cause similar side effects such as dizziness or nausea. While naltrexone does not have a broad sedating profile, combined effects can still occur. Share all supplements and natural health products, since some may affect liver function. A pharmacist can provide an interaction review tailored to your medication list.
Overdose, Emergencies, and What to Do
An overdose of Revia itself is not typically associated with the same respiratory depression risk as opioid overdose, but taking more than prescribed can still cause significant side effects and requires medical advice. More importantly, a major safety concern is opioid overdose risk if someone tries to override receptor blockade or returns to opioid use after stopping naltrexone. Reduced tolerance after abstinence can make previously tolerated doses fatal. If opioid exposure occurs, seek urgent help.
If you suspect an opioid overdose in yourself or someone else, call emergency services immediately. Signs include slowed or stopped breathing, blue lips or fingertips, pinpoint pupils, or inability to wake. In Canada, naloxone kits are widely recommended for overdose response and can be life-saving. Even if a person is on naltrexone, naloxone may still be used in an emergency when opioid overdose is suspected, and emergency assessment is essential.
If you have taken Revia and now require emergency pain treatment, disclose the medication right away. Clinicians can use non-opioid analgesics, regional anesthesia techniques, and other strategies. Do not attempt to self-manage severe pain with leftover opioids. Emergency departments are equipped to handle these situations when they have accurate information.
Storage, Handling, and Medication Safety at Home
Store Revia at room temperature in its original packaging, away from excess heat, moisture, and direct sunlight. Keep it out of reach of children and pets. Avoid storing tablets in bathrooms where humidity fluctuates. Proper storage helps maintain medication integrity and reduces accidental ingestion.
Do not share Revia with anyone else, even if their symptoms seem similar. The opioid-blocking effects can be dangerous for someone using opioids or requiring opioid pain control. If tablets are no longer needed or are expired, ask a Canadian pharmacy about take-back options. Safe disposal reduces the risk of misuse and environmental contamination.
If your tablets change appearance between refills, check with the pharmacy before taking them. Generic products can look different, but verification is wise. Keep a current medication list in your wallet or phone. This is helpful in emergencies and routine medical visits.
Buying Revia Through an Online Pharmacy in Canada
In Canada, access to naltrexone is generally prescription-based, and online supply is typically provided through licensed pharmacy services that verify a valid prescription. If a site claims to provide Revia “without prescription,” treat that as a safety red flag, because it may bypass medical screening and could involve counterfeit or inappropriate products. Requirements can vary by province and by pharmacy licensing rules. A legitimate process focuses on patient identity checks, appropriate clinical review, and secure dispensing.
If you are looking to buy Revia online, prioritize pharmacies that provide pharmacist access and clear contact information. A safe service will ask for your prescription, confirm your opioid-free status when relevant, and screen for interactions and contraindications. It should also provide proper labeling, patient information, and discreet packaging. These steps protect you and improve treatment success.
Illustrative pricing in other Canadian online pharmacies can vary based on brand versus generic, tablet strength, quantity, and dispensing fees. As a general guide, monthly costs for oral naltrexone may range from modest to moderate, and insurance or provincial coverage can change out-of-pocket costs significantly. Because prices change, the most reliable approach is to request a quote and confirm what is included, such as pharmacist counselling and shipping. If cost is a barrier, ask about generic options and coverage pathways.
How to Place an Order, Shipping, and Package Tracking
Ordering Revia through a reputable online pharmacy usually begins with creating a patient profile and providing prescription details. Some services accept prescriptions sent directly from your prescriber, while others allow you to upload documentation for verification. Expect to answer safety questions about opioid use, liver history, pregnancy status, and current medications. This screening is an important part of responsible dispensing.
After the pharmacy team validates the prescription and completes a clinical check, the medication is prepared and shipped in discreet packaging. Many services provide package tracking so you can follow the shipment from dispatch to delivery. Tracking helps reduce missed deliveries and supports continuity, which matters for daily medications. If your delivery is delayed, contact the pharmacy promptly to avoid gaps in treatment.
Before finalizing an order, confirm the return/refund policy, temperature considerations during shipping, and how the pharmacy handles lost packages. Ensure there is a clear way to reach a pharmacist for questions about side effects, missed doses, or interactions. Keep your refill timing in mind, since waiting until the last dose increases the risk of interruption. If you travel within Canada, ask about address changes and delivery timelines.
Alternatives to Revia and When They May Be Considered
Alternatives depend on the condition being treated. For alcohol use disorder, other medications may be considered based on medical history, treatment goals, and tolerability, and non-medication supports remain central. For opioid use disorder, other evidence-based options include opioid agonist therapies that work differently from naltrexone and may be preferred for many patients. The right choice is individualized and should be discussed with a clinician experienced in addiction care.
Revia may be a good fit for people who want an opioid-free maintenance option and can maintain adherence, while other options may be better for those at high relapse risk or who benefit from medications that reduce withdrawal and cravings through receptor activation. Accessibility, follow-up availability, and patient preference are important considerations. If one option is not effective or tolerable, it is common to reassess rather than abandon treatment. Recovery plans can evolve over time.
Psychosocial treatments are not “alternatives” so much as essential partners to medication. Counselling, relapse-prevention planning, peer support, and addressing housing, employment, and mental health needs can improve outcomes. If you are uncertain where to start, ask your pharmacist or clinician for local resources in your province. Combining supports often provides the most resilient results.
Frequently Asked Questions
Is Revia the same as naltrexone?
Revia is a brand name for naltrexone. Different brands may look different, but they contain the same active ingredient when the strength matches. If you’re switching brands, confirm the dose and directions on the label to avoid mix-ups.
Do I need to be opioid-free before starting Revia?
Revia can trigger sudden opioid withdrawal if opioids are still in your system. Before starting, clinicians typically confirm you are opioid-free for an appropriate period based on the opioid used and your medical history. If you’re unsure, ask your prescriber or pharmacist before taking the first dose.
Can Revia be used if I’m still drinking alcohol?
Revia is used to support treatment for alcohol dependence, and some people start it while they are still drinking. The safest approach depends on your overall health, liver function, and treatment plan. Do not use it as a substitute for medical care or counselling supports.
What should I do if I need pain control while taking Revia?
Revia blocks opioid pain medicines, which can make typical opioid-based pain control ineffective. Tell any doctor, dentist, or emergency team that you take naltrexone before procedures or treatment. Do not attempt to override the blockade with opioids, as this can be dangerous.
Is Revia safe during pregnancy or breastfeeding?
If you are pregnant, trying to conceive, or breastfeeding, discuss Revia with your prescriber as the benefits and risks must be weighed for your situation. Decisions often consider the condition being treated, relapse risk, and available alternatives. Do not start or stop Revia on your own without medical guidance.
Can Revia affect my liver, and do I need monitoring?
Naltrexone can affect the liver, particularly in people with existing liver disease or when used inappropriately. Prescribers may order baseline and follow-up liver tests based on your risk factors and symptoms. Contact a clinician promptly if you notice signs such as unusual fatigue, dark urine, or yellowing of the skin or eyes.
What if I miss a dose of Revia?
If you miss a dose, take it when you remember unless it’s close to your next scheduled dose. Do not double up doses to make up for a missed one. If you miss doses often, ask your pharmacist about strategies to stay on track.
Can I buy Revia online in Canada?
You can buy medications through an online pharmacy in Canada, but requirements vary by province and by the medication. Many pharmacies will request a valid prescription and may contact your prescriber to confirm appropriateness and safety. Choose a licensed pharmacy and avoid sites that claim Revia is available “without a prescription,” as that can be a safety and legal red flag.
Pharmacist Review
The information on this Revia product page has been professionally reviewed for clinical accuracy and patient-safety relevance by a licensed pharmacist in Canada.
| Reviewer | Alyssa M. Chen |
|---|---|
| Professional title | Doctor of Pharmacy (PharmD), Registered Pharmacist (RPh) |
| Professional identifier | OCP Registration No. 224981 |
| Regulatory body | Ontario College of Pharmacists (OCP) |
| Review date | July 17, 2026 |
This review focuses on whether the content presents Revia in a balanced, patient-appropriate way, including typical use, dosing and administration considerations, important precautions, common adverse effects, interactions, and when urgent medical advice is needed. It is not a substitute for individualized assessment, diagnosis, or monitoring.
Medical disclaimer: This material is provided for informational purposes only and does not replace consultation with a physician or other qualified healthcare professional. Always follow your prescriber’s directions and the official product information, and seek medical advice if symptoms persist, worsen, or if you suspect an adverse reaction.
Store Location & Pharmacy Hours
Picking up Revia in person? You can find our pharmacy at:
1055 W Georgia St
Vancouver, BC V6B 2W9
Canada
Opening hours
| Day | Hours |
|---|---|
| Monday–Friday | 9:00 a.m.–7:00 p.m. |
| Saturday | 10:00 a.m.–5:00 p.m. |
| Sunday | 11:00 a.m.–4:00 p.m. |