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Guanfacine (Tenex, Intuniv)

How does this medicine work?

Guanfacine (gwan-fa-seen) is used to treat high blood pressure. It may also be used to treat symptoms of attention deficit and hyperactivity disorder (ADHD). Symptoms of ADHD include short attention span, impulsivity (acting on sudden urges), and frequent hyperactivity (body restlessness). This medicine has a calming effect in children with ADHD.

It may also be used to treat tics (repeated muscle twitching) and other conditions.

How should I give it?

Guanfacine comes in an immediate release pill form (Tenex®) and an extended release tablet (Intuniv®). The dose must be changed gradually. Do not stop the medicine without checking with your doctor or nurse practitioner.

Give it at a regular time to keep a steady level in the bloodstream. The last dose may be given at bedtime to avoid being too tired during the day.

___ For children who cannot swallow pills and it is not the brand Intuniv®:

  • Crush it between 2 spoons, inside a plastic bag, or in folded paper.
  • Mix the powder with a very small amount (about 1 teaspoon) of soft food, such as applesauce, chocolate syrup, ice cream, jelly, or yogurt. Make sure your child takes all of the mixture.

___ Intuniv® must be swallowed whole. Do not crush or chew.

Are there any precautions about food or other medicines?

You can give it with or without food.

Follow any other directions provided by your doctor or nurse practitioner.

There are certain medicines that may interact with guanfacine. Check with the doctor, nurse practitioner, or pharmacist before giving any other prescription or non-prescription medicines, herbs, or vitamins.

What should I do if a dose is missed?

If a dose is missed, give it as soon as you remember that day. Never give a double dose.

If your child vomits (throws up) within 30 minutes after receiving a dose, please call the clinic.

What are the side effects?


  • drowsiness
  • dizzy, lightheaded
  • dry mouth
  • decreased blood pressure


  • tired or weak
  • headache
  • constipation
  • nausea (upset stomach)

The person taking this medicine should not drive, operate machinery, or do anything else that could be dangerous until it is clear that no risky side effects are present.

When should I call the clinic?

  • irregular heartbeat
  • chest pain
  • extreme depression
  • severe weakness
  • very dizzy or lightheaded
  • fainting
  • shortness of breath
  • vomiting (if due to this medicine)

What else do I need to know?

Check with your doctor or nurse practitioner before stopping this medicine. The dose is usually lowered over time.

You and your child should know the names of all the medicines he or she is taking. Share this information with anyone involved in your child's care. Please bring the medicine container when your child comes to the clinic or emergency department.

Always make sure you have enough medicine on hand. Each time you refill your prescription, check to see how many refills are left. If no refills are left, the pharmacy will need 2 or 3 days to contact the clinic to renew the prescription.

Check the label and expiration date before giving each dose. Ask your pharmacist what to do with outdated or unused medicines. If there is no "take-back" program, you can throw them in the garbage after mixing with coffee grounds or kitty litter and sealing in a plastic bag.

Store all medicines in their original container and away from direct sunlight or heat. Do not store in humid places such as the bathroom. Keep them out of children's reach, locked up if possible.

If too much or the wrong kind of medicine is taken, call the Poison Control Center at 1-800-222-1222. If your child is unconscious or has a seizure, call 911.


This is not specific to your child but provides general information. If you have any questions, please call your clinic or pharmacy.

Children's Hospitals and Clinics of Minnesota
Last reviewed 8/2015

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This page is not specific to your child, but provides general information on the topic above. If you have any questions, please call your clinic. For more reading material about this and other health topics, please call or visit Children's Minnesota Family Resource Center library, or visit

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