naltrexone microspheres

For the best possible benefit, it is important to receive each scheduled dose of this medication as directed. If you miss a dose, contact your doctor or pharmacist immediately to establish a new dosing schedule.

Read the Medication Guide provided by your pharmacist before you start using naltrexone and each time you get a refill. If you have any questions, ask your doctor or pharmacist. Before you receive this medication, you should have a urine test to check for recent opiate drug use. Your doctor may give you another medication (naloxone challenge test) to check for opiate use. Do not use alcohol/any opiates for at least 7 days before starting naltrexone. This medication is injected into a muscle in the buttock by a health care professional, usually once a month or as directed by your doctor. Dosage is based on your medical condition and response to treatment. Your doctor may start you at a lower dose and monitor you for any side effects or withdrawal symptoms before increasing your dose. To get the most benefit from this medication, use it regularly and continue your treatment program. To help you remember, mark your calendar with the days you need to receive this drug and/or be treated. Tell your doctor if you start drinking alcohol again or start using drugs.

Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval. Some products that may interact with this drug include: "blood thinners" (e.g., warfarin, enoxaparin), cough medication (e.g., dextromethorphan), diarrhea medication (e.g., diphenoxylate), narcotic medication (e.g., codeine, hydrocodone, propoxyphene). This medication may interfere with certain laboratory tests (including drug tests), possibly causing false test results. Make sure laboratory personnel and all your doctors know you use this drug.

Your condition can cause complications in a medical emergency. For information about enrolling in MedicAlert, call 1-800-854-1166 (USA) or 1-800-668-1507 (Canada).

Laboratory and/or medical tests (e.g., liver function tests) should be performed periodically to monitor your progress or check for side effects. Consult your doctor for more details.

If overdose is suspected, contact your local poison control center or emergency room immediately. US residents can call the US National Poison Hotline at 1-800-222-1222. Canada residents can call a provincial poison control center.

Before using naltrexone, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details. This medication should not be used if you have certain medical conditions. Before using this medicine, consult your doctor or pharmacist if you: have taken any type of opioid drugs (e.g., codeine, oxycodone, morphine) in the last 7 to 10 days, are currently withdrawing from or dependent on any opioid (including methadone maintenance), currently have liver disease/liver failure. Before using this medication, tell your doctor or pharmacist your medical history, especially of: bleeding problems (e.g., hemophilia, low platelets), kidney disease, liver problems. You should carry or wear medical identification stating that you are using this drug so that appropriate treatment can be given in a medical emergency. See also Medical Alert section. This drug may make you dizzy or drowsy. Do not drive, use machinery, or do any activity that requires alertness until you are sure you can perform such activities safely. Avoid alcoholic beverages. After stopping naltrexone treatment, you may be more sensitive to lower doses of opioids, increasing your risk of serious, possibly fatal side effects from the narcotic (e.g., decreased breathing, loss of consciousness). Before having surgery or any medical/dental treatment, tell your doctor or dentist that you are using this medication. This medication blocks the effects of opiate drugs (including heroin) and similar drugs (opioids). However, large doses of heroin or narcotics can overcome this block. Trying to overcome this block is very dangerous and may cause serious injury, loss of consciousness, and death. Make sure you completely understand and accept the risks and benefits of using this medication. Follow your doctor's instructions closely. During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor. This drug passes into breast milk and may have undesirable effects on a nursing infant. Consult your doctor before breast-feeding.

Not applicable. This medication is given in a hospital and will not be stored at home.

Nausea, headache, dizziness, drowsiness, anxiety, tiredness, and loss of appetite may occur. If you have been using opiate narcotics regularly, mild opiate withdrawal symptoms may occur, including abdominal cramps, restlessness, bone/joint pain, muscle aches, and runny nose. If any of these effects persist or worsen, tell your doctor or pharmacist promptly. Pain/redness/swelling/itching/bruising at the injection site may also occur. If any of these effects steadily worsen, or if they persist longer than two weeks, tell your doctor or pharmacist immediately. Rarely, a severe injection site reaction can cause permanent injury if not treated. Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects. Sudden opiate withdrawal symptoms can occur within minutes after using naltrexone if you are physically addicted to narcotics. Tell your doctor immediately if any of these withdrawal symptoms occur: vomiting, diarrhea, mental/mood changes (e.g., anxiety, confusion, extreme sleepiness, visual hallucinations). Tell your doctor right away if you have any serious side effects, including: fast/irregular heartbeat, depression/rare thoughts of suicide, signs of a serious breathing problem/pneumonia (e.g., cough, shortness of breath, wheezing), blisters/sores at injection site. Get medical help right away if this rare but very serious side effect occurs: chest pain. Naltrexone has rarely caused serious liver disease. The risk is increased when larger doses are used. (See also Warning section.) A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing. This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist. In the US - Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088. In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Naltrexone can cause liver problems when given in large doses. Stop using this medication and tell your doctor immediately if symptoms of liver problems develop (e.g., persistent nausea, unusual tiredness, abdominal/stomach pain, yellowing eyes/skin, pale stools, dark urine). This medication should not be used in patients who already have liver problems (e.g., active hepatitis, liver failure). (See also Side Effects section.)