Guanfacine (Oral)

Guanfacine (By Mouth)

Guanfacine (GWAHN-fa-seen)

Treats high blood pressure.

Brand Name(s):

There may be other brand names for this medicine.

When This Medicine Should Not Be Used:

You should not use this medicine if you have had an allergic reaction to guanfacine.

How to Use This Medicine:


  • Your doctor will tell you how much medicine to take and how often.  
  • Take this medicine exactly as your doctor ordered. Even if you feel fine your blood pressure can still be high.  
  • May be taken with or without food.  
  • If you are taking guanfacine once a day, take the dose at bedtime to avoid being drowsy during the day (unless your doctor tells you differently).

If a dose is missed::

  • Take the missed dose as soon as you remember.  
  • Skip the missed dose if it is almost time for your next regular dose and take your medicine at your usual time.  
  • If you miss more than two doses in row, talk with your doctor.  
  • You should not use two doses at the same time.

How to Store and Dispose of This Medicine:

  • Store at room temperature, away from heat, moisture, and direct light.  
  • Keep all medicine out of the reach of children.

Drugs and Foods to Avoid:

Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.

  • Avoid drinking alcohol while using this medicine.  
  • Make sure your doctor knows if you are also using any medicine that makes you sleepy, such as sleeping pills, tranquilizers, cold or allergy medicine, narcotic pain-killers, or muscle relaxers.

Warnings While Using This Medicine:

  • Check with your doctor before using guanfacine if you have heart or liver disease, depression, or if you have had a heart attack or stroke.  
  • Talk with your doctor before using this medicine if you are pregnant or breastfeeding.  
  • Do not stop using this medicine suddenly without talking to your doctor. You may need to use smaller and smaller doses before completely stopping the medicine.  
  • Tell your doctor or dentist that you are using guanfacine before you have any kind of surgery.  
  • Guanfacine can make you dizzy or drowsy. Be careful if you drive a car or operate machinery.  
  • To avoid dizziness from this medicine, stand up slowly from a sitting or lying position.

Possible Side Effects While Using This Medicine:

Call your doctor right away if you notice any of these side effects:

  • Irregular heartbeat  
  • Chest pain  
  • Trouble breathing  
  • Severe weakness

If you notice these less serious side effects, talk with your doctor:

  • Headache or eye irritation  
  • Trouble sleeping  
  • Constipation  
  • Drowsiness or dizziness  
  • Dry mouth and nose  
  • Trouble having sex  
  • Depressed mood

Johns Hopkins patient information

Copyright 1996-2014 Cerner Multum, Inc. Version: 16.02.
Revision date: June 14, 2011
Last revised: by Janet A. Staessen, MD, PhD

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CONDITIONS OF USE: The information in this database is intended to supplement, not substitute for, the expertise and judgment of healthcare professionals. The information is not intended to cover all possible uses, directions, precautions, drug interactions or adverse effects, nor should it be construed to indicate that use of a particular drug is safe, appropriate or effective for you or anyone else. A healthcare professional should be consulted before taking any drug, changing any diet or commencing or discontinuing any course of treatment.

The drug reference included in this section is provided by Cerner Multum, Inc., of Denver, Colorado. Armenian Medical Network receives monthly updates from Multum.