naltrexone (generic name)

It blocks the 'high' that these substances can give you
(nal TREX one)
Table of Contents
powered by healthline

Average Ratings

What is this medicine?

NALTREXONE (nal TREX one) helps you to remain free of your dependence on opiate drugs or alcohol. It blocks the 'high' that these substances can give you. This medicine is combined with counseling and support groups.

What should I tell my health care provider before I take this medicine?

They need to know if you have any of these conditions:
  • if you have used drugs or alcohol within 7 to 10 days
  • kidney disease
  • liver disease, including hepatitis
  • an unusual or allergic reaction to naltrexone, other medicines, foods, dyes, or preservatives
  • pregnant or trying to get pregnant
  • breast-feeding

How should I use this medicine?

Take this medicine by mouth with a full glass of water. Follow the directions on the prescription label. Do not take this medicine within 7 to 10 days of taking any opioid drugs. Take your medicine at regular intervals. Do not take your medicine more often than directed. Do not stop taking except on your doctor's advice.

Talk to your pediatrician regarding the use of this medicine in children. Special care may be needed.

What if I miss a dose?

If you miss a dose and remember on the same day, take the missed dose. If you do not remember until the next day, ask your doctor or health care professional about rescheduling your doses. Do not take double or extra doses.

What may interact with this medicine?

Do not take this medicine with any of the following medications:
  • any prescription or street opioid drug like codiene, heroin, methadone

This medicine may also interact with the following medications:

  • disulfiram
  • thioridazine

What should I watch for while using this medicine?

Visit your doctor or health care professional regularly.

Never try to overcome this medicine by taking large amounts of opioid drugs. You may cause an overdose, coma and death.

Tell all of your doctors and health care providers that you are taking this medicine. For emergencies, carry a medication card. Or, wear a medical identification bracelet or chain to say that you take this medicine.

What side effects may I notice from receiving this medicine?

Side effects that you should report to your doctor or health care professional as soon as possible:
  • breathing problems
  • changes in vision, hearing
  • confusion
  • dark urine
  • depressed, thoughts of suicide
  • diarrhea with vomiting
  • fast, irregular heart beat
  • hallucination, loss of contact with reality
  • right upper belly pain
  • unusually weak or tired
  • white bowel movements
  • yellowing of the eyes or skin

Side effects that usually do not require medical attention (report to your doctor or health care professional if they continue or are bothersome):

  • aches, pains
  • change in sex drive or performance
  • feeling anxious, dizzy, restless, tearful
  • headache
  • loss of appetite, nausea
  • runny nose, sinus problems, sneezing
  • stomach cramps
  • trouble sleeping

Where should I keep my medicine?

Keep out of the reach of children.

Store at room temperature between 20 and 25 degrees C (68 and 77 degrees F). Throw away any unused medicine after the expiration date.

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Last Updated: July 13, 2009
Licensed from
Top of page
General Drug Tools
General Drug Tools view all tools
Tools for
Healthy Living
Tools for Healthy Living view all tools
Search Tools
Search Tools view all tools
Insurance Plan Tools
Insurance Plan Tools view all tools

What is a reference number?

When you register on this site, you are assigned a reference number. This number contains your profile information and helps UnitedHealthcare identify you when you come back to the site.

If you searched for a plan on this site in a previous session, you might already have a reference number. This number will contain any information you saved about plans and prescription drugs. To use that reference number, click on the "Change or view saved information" link below.

You can retrieve information from previous visits to this site, such as saved drug lists and Plan Selector information.