Naltrexone (By injection)
Helps prevent alcohol or drug abuse relapse.
When This Medicine Should Not Be Used
How to Use This Medicine
- Your doctor will prescribe your exact dose. A nurse or other health provider will give you this medicine as a shot into your buttocks muscle. It is usually given every 4 weeks.
- Missed dose: If you miss your scheduled dose, call to make another appointment as soon as possible.
- This medicine should come with a Medication Guide. Ask your pharmacist for a copy if you do not have one.
Drugs and Foods to Avoid
Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.
- Any prescription narcotic medicine, such as cough syrup, will not work well while you are being treated with this medicine.
- Do not drink alcohol while you are using this medicine.
Warnings While Using This Medicine
- Make sure your doctor knows if you are pregnant or breastfeeding, or if you have kidney problems, liver problems, lung or breathing problems, low platelets in the blood, or bleeding problems such as hemophilia.
- 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.
- Call your doctor if you have a reaction to the shot that does not go away or gets worse within 2 weeks after you get the shot.
- This medicine can cause serious liver problems or eosinophilic pneumonia.
- This medicine may increase thoughts of suicide. Tell your doctor right away if you start to feel depressed or have thoughts about hurting yourself.
- Do not drive, use machines, or do anything else that could be dangerous until you know how this medicine affects you.
- Tell any doctor or dentist who treats you that you are using this medicine. This medicine may affect certain medical test results. You may want to carry a card or a paper with you that says you are receiving this medicine.
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, depression, or unusual thoughts and behaviors
- Chest pain or trouble breathing
- Dark urine or pale stools, nausea, vomiting, loss of appetite, pain in your upper stomach, yellow skin or eyes
- Dizziness, drowsiness, or fainting
- Fast, slow, or pounding heartbeat
- Fever, chills, cough, runny or stuffy nose, sore throat, and body aches
- Pain, itching, burning, swelling, or a lump under your skin where the shot was given
- 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:
- Back, muscle, or joint pain
- Change in appetite
- Constipation, diarrhea, or stomach 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 10/12/2016
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