Naltrexone (By mouth)
Helps prevent alcohol or drug abuse relapse.
When This Medicine Should Not Be Used
How to Use This Medicine
- Take your medicine as directed. Your dose may need to be changed several times to find what works best for you.
- Missed dose: Take a dose as soon as you remember. If it is almost time for your next dose, wait until then and take a regular dose. Do not take extra medicine to make up for a missed dose.
- Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light.
Drugs and Foods to Avoid
Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.
- Do not take this medicine if you are using or have used heroin or other narcotic drugs (such as buprenorphine, codeine, methadone, or other habit-forming painkillers) within the past 7 to 10 days.
- Some foods and medicines can affect how naltrexone works. Tell your doctor if you are using disulfiram, thioridazine, or medicine for pain, diarrhea, cough, or colds.
Warnings While Using This Medicine
- Tell your doctor if you are pregnant, planning to become pregnant, or breastfeeding, or if you have kidney disease, liver disease (including hepatitis B or C, cirrhosis), or a history of depression or mental illness.
- You have a higher risk of accidental overdose, serious injury, or death if you use heroin or any other narcotic medicine while you are being treated with naltrexone. Also, naltrexone prevents you from feeling the effects of heroin if you use it.
- This medicine may increase thoughts of suicide. Tell your doctor right away if you start to feel depressed or have thoughts about hurting yourself.
- This medicine may cause liver problems.
- This medicine may make you dizzy or drowsy. Do not drive or do anything else that could be dangerous until you know how this medicine affects you.
- Tell your doctor and all other caregivers that you are taking naltrexone. You may need to carry a card to let others know you are taking this medicine if you have a medical emergency. Ask your doctor about this.
- Your doctor will do lab tests at regular visits to check on the effects of this medicine. Keep all appointments.
Possible Side Effects While Using This Medicine
Call your doctor right away if you notice any of these side effects:
- Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing
- Anxiety, confusion, depression, or unusual thoughts and behaviors
- Dark urine or pale stools, nausea, vomiting, loss of appetite, stomach pain, or yellow skin or eyes
- Trouble sleeping, getting upset easily, a big increase in energy, or reckless behavior
If you notice these less serious side effects, talk with your doctor:
- Constipation, diarrhea, stomach cramps or pain
- Dizziness or drowsiness
- Joint or muscle pain
If you notice other side effects that you think are caused by this medicine, tell your doctor
Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088
- Last reviewed on 10/4/2017
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