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Naltrexone HCl oral

Important Note

The following information is intended to supplement, not substitute for, the expertise and judgment of your physician, pharmacist or other healthcare professional. It should not be construed to indicate that use of the drug is safe, appropriate, or effective for you. Consult your healthcare professional before using this drug.




WARNING: Naltrexone can cause liver problems when given in doses that are too large. Stop using this medication and notify your doctor immediately if symptoms of liver problems develop, such as abdominal or stomach pain, yellowing eyes or skin, or dark urine. This medication must not be used in patients who already have liver problems (e.g., hepatitis, liver failure).


This medication is used to maintain a drug-free state in those previously addicted to opiates. It is used in combination with behavior adjustment programs and only after having completed a detoxification program. Naltrexone is also used in the treatment of alcoholism. This medication must not be used in persons currently dependent on narcotics.

How To Use

This medication must be used under close medical supervision. Take this as directed. Do not increase your dose, take this more often or stop taking this without first consulting your doctor.

Side Effects

Anxiety, nervousness, headache, sleeping trouble, stomach upset, nausea, sneezing, nasal stuffiness, muscle pain, decreased sexual function or desire, blurred vision, thirst, ringing in the ears, weakness and tiredness may occur. If any of these effects persist or worsen, inform your doctor. Notify your doctor if you develop: skin rash, confusion, mood changes, hallucinations, vomiting, severe diarrhea, breathing trouble. If you notice other effects not listed above, contact your doctor or pharmacist.


Tell your doctor you medical history, especially: liver disease, any alcohol or drug use, any allergies. This medication blocks the effects of narcotics and heroin. However, large doses of heroin or narcotics can overcome this block and may cause serious injury, coma and even death. Make sure you understand completely the risks and benefits of using this medication. Follow your doctors instructions closely. This medication should be used only if clearly needed during pregnancy. Discuss the risks and benefits with your doctor. It is not known if this medication is excreted into breast milk. Consult your doctor before breast-feeding.

Drug Interactions

Tell your doctor of all over-the-counter and prescription medication you may use, especially: cough medication, diarrhea medication, narcotic medication. Do not start or stop any medicine without doctor or pharmacist approval.


If overdose is suspected, contact your local poison control center or emergency room immediately. Symptoms of overdose may include yellowing eyes or skin; dark urine, fever, or fatigue.


It is recommended you carry or wear medical identification stating you are taking this drug so that appropriate treatment can be given in a medical emergency.

Missed Dose

If you miss a dose, take it as soon as remembered; do not take it if it is near the time for the next dose, instead, skip the missed dose and resume your usual dosing schedule. Do not "double-up" the dose to catch up.


Store at room temperature between 59 and 86 degrees F (15 to 30 degrees C) away from heat and light. Do not store in the bathroom.

Medical Alert

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