Revia (Naltrexone) belongs to a group of medications known as pure opioid antagonists. It is used to help individuals who were previously dependent on drugs of addiction (such as alcohol, or opiate drugs such as Methadone and heroin) to remain free from their dependence.

Opiate drugs (also known as opioid drugs) and opioids that are naturally part of the body affect certain parts of the brain called opiate receptors. Revia (Naltrexone) works by binding to these opiate receptors to block the effects of opiates drugs and the body's own opiates. It is believed that this helps prevent a person from returning to using these substances.

Revia (Naltrexone) is used together with other forms of treatment such as psychological counselling and social support.

Your doctor may have suggested Revia (Naltrexone) for conditions other than those listed in these drug information articles. As well, some forms of Revia (Naltrexone) may not be used for all of the conditions discussed here. If you have not discussed this with your doctor or are not sure why you are taking Revia (Naltrexone), speak to your doctor. Do not stop taking Revia (Naltrexone) without consulting your doctor.

Do not give Revia (Naltrexone) to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take Revia (Naltrexone) if their doctor has not prescribed it.

The dose of Revia (Naltrexone) depends on the type of dependence it is being used to treat, and whether administration of the medication will be supervised.

To treat Alcoholism, the usual recommended dose is 50 mg once daily.

To treat opioid dependence (e.g., addiction to methadone or heroin), the dose will vary but the usual starting dose is 25 mg once daily, to be slowly increased to the most appropriate dose.

Your doctor will determine a dose and dosing schedule for your individual situation. It is important that you take Revia (Naltrexone) exactly as prescribed by your doctor.

Your doctor may request a urine sample before initiating treatment with Revia (Naltrexone) in order to make sure that you have not used any narcotics (opioid drugs) within the previous 7 to 10 days. You should not take Revia (Naltrexone) if there is any possibility that you have used an opiate within the previous 7 to 10 days. If there is any question about your opiate use, your doctor may request that you take a NARCAN challenge test in order to confirm that your body is opiate-free before you take Revia (Naltrexone).

If you miss a dose, take it as soon as possible and continue with your regular schedule. If it is almost time for your next dose, skip the missed dose and continue with your regular dosing schedule. Do not take a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.

Store Revia (Naltrexone) at room temperature, protect it from light and moisture, and keep it out of the reach of children.

Do not dispose of medications in wastewater (e.g. down the sink or in the toilet) or in household garbage. Ask your pharmacist how to dispose of medications that are no longer needed or have expired.

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes Revia (Naltrexone). If you are concerned about side effects, discuss the risks and benefits of Revia (Naltrexone) with your doctor.

The following side effects have been reported by at least 1% of people taking Revia (Naltrexone). Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• abdominal pain or cramps
• anxiety
• chills
• Constipation
• decreased libido
• delayed ejaculation
• difficulty sleeping
• drowsiness
• Dry Mouth
• fatigue
• feeling down
• headache
• increased energy
• increased thirst
• indigestion
• irritability
• joint and muscle pain
• loss of appetite
• low energy
• nausea
• nervousness
• vomiting
• weight changes

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• dizziness
• increased blood pressure
• signs of liver problems (e.g., nausea, vomiting, Diarrhea, loss of appetite, weight loss, yellowing of the skin or whites of the eyes, dark urine, pale stools)
• increased blood pressure
• skin rash
• symptoms of a cold (e.g., nasal congestion, runny nose, sneezing, sore throat, excess phlegm, cough, hoarseness)
• symptoms of Depression (e.g., low energy, feelings of worthlessness, guilt, helplessness or hopelessness)
• symptoms of narcotic withdrawal (e.g., tearfulness, nausea, abdominal cramps, restlessness, bone or joint pain, muscle pain, nasal irritation)

Stop taking the medication and seek immediate medical attention if any of the following occur:

• attempts at suicide or thoughts of suicide
• rapid or irregular heartbeat
• signs of an allergic reaction (such as difficulty breathing, Hives, skin rash, swelling of the face or throat)

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking Revia (Naltrexone).

Each pale yellow, film-coated, capsule-shaped tablet, engraved with "R11" on one side and with "50" and a bisect on the other side, contains 50 mg of Revia (Naltrexone) HCl. Nonmedicinal ingredients: colloidal silicon dioxide, crospovidone, lactose monohydrate, magnesium stearate, microcrystalline cellulose, and Pale Yellow Opadry YS-1-6378-G.

Do not take Revia (Naltrexone) if you:

• are allergic to Revia (Naltrexone) or to any of the ingredients of the medication
• are dependent upon opiates, including if you are receiving opiate agonists (e.g., methadone)
• are experiencing opiate withdrawal
• are receiving opiate analgesics (e.g., narcotics medications such as Oxycodone and Codeine)
• have a urine test that is positive for opiates
• have acute hepatitis or liver failure
• have failed the NARCAN challenge (a test used to determine if you have used opiates)

There may be an interaction between Revia (Naltrexone) and any of the following:

• disulfiram
• Glyburide
• opiate-containing medications (e.g., codeine, Morphine, oxycodone)
• Nabilone
• Naloxegol

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with Revia (Naltrexone). Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the Nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.