Naltrexone Side Effects

Possible side effects of naltrexone are listed below. Tell your doctor if these side effects are severe or persist after a few days.

• Stomach pain
• Nausea
• Vomiting
• Diarrhea
• Constipation
• Loss of appetite
• Dizziness
• Drowsiness
• Headache
• Mood changes (anxiety, irritability, tearfulness, nervousness)
• Sleep problems
• Changes in energy levels
• Muscle pain or joint pain
• Rash
• Injection site reaction (tenderness, bruising, itching)

Naltrexone can cause more serious side effects. Call your doctor immediately or seek emergency medical help if you develop the following symptoms:

• Rash, hives, itching
• Chest pain
• Shortness of breath
• Difficulty breathing or swallowing
• Wheezing
• Hoarseness
• Swelling of the eyes, face, lips, tongue, or throat
• Severe diarrhea or vomiting
• Blurred vision
• Confusion
• Hallucinations (seeing or hearing things that aren’t there)

The above list may not include all the potential adverse effects of naltrexone. Contact your doctor for medical advice about side effects if they are unusual or severe or do not get better over time. You can also report unusual side effects to the Food and Drug Administration at 1-800-FDA-1088.

Naltrexone Overdose: In case of an overdose of naltrexone, call your doctor immediately or call the National Poison Control Center at 1-800-222-1222. Call 911 if a person cannot be awakened, has trouble breathing, has collapsed, or has had a seizure. Signs and symptoms of a naltrexone overdose may include dizziness, drowsiness, nausea, and vomiting.

Source: FDA