Generic Name: guanfacine (GWAHN fa seen)
Brand Name: Intuniv, Tenex
What is guanfacine?
Guanfacine reduces nerve impulses in your heart and blood vessels. Guanfacine works by relaxing blood vessels, which lowers blood pressure and improves blood flow.
Guanfacine is used to treat high blood pressure (hypertension). It is sometimes given together with other blood pressure medications.
Guanfacine is also used to treat attention deficit hyperactivity disorder (ADHD) in children who are at least 6 years old.
Guanfacine may also be used for purposes not listed in this medication guide.
What is the most important information I should know about guanfacine?
Follow all directions on your medicine label and package. Tell each of your healthcare providers about all your medical conditions, allergies, and all medicines you use.
What should I discuss with my healthcare provider before taking guanfacine?
You should not use this medication if you are allergic to guanfacine.
To make sure you can safely take guanfacine, tell your doctor if you have any of these other conditions:
heart disease or heart block;
coronary artery disease or a history of stroke;
low blood pressure;
liver disease; or
if you have recently had a heart attack.
FDA pregnancy category B. This medication is not expected to be harmful to an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant during treatment.
It is not known whether guanfacine passes into breast milk or if it could harm a nursing baby. Tell your doctor if you are breast-feeding a baby.
How should I take guanfacine?
Follow all directions on your prescription label. Your doctor may occasionally change your dose to make sure you get the best results. Do not take this medicine in larger or smaller amounts or for longer than recommended.
If you take Intuniv to treat ADHD, take your dose in the morning.
If you take Tenex to treat hypertension, you may need to take your dose at bedtime if guanfacine causes severe drowsiness. Follow your doctor's instructions.
Do not crush, chew, break, or open an Intuniv extended-release tablet. Swallow it whole.
If there are any changes in the brand, strength, or type of guanfacine you use, your dosage needs may change. Always check your refills to make sure you have received the correct brand and type of medicine prescribed by your doctor. Ask the pharmacist if you have any questions about the medicine you receive at the pharmacy.
Your doctor will need to check your progress while you are using guanfacine. Your blood pressure and heart rate may also need to be checked.
You should not stop using guanfacine suddenly. Stopping suddenly may make your condition worse, and you could have unpleasant symptoms.
If you are being treated for high blood pressure, keep using this medication even if you feel well. High blood pressure often has no symptoms. You may need to use blood pressure medication for the rest of your life.
Store at room temperature away from moisture, heat, and light.
What happens if I miss a dose?
Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.
Call your doctor for instructions if you miss more than 2 doses in a row.
What happens if I overdose?
Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.
Overdose symptoms may include severe drowsiness, slow heart rate, and feeling like you might pass out.
What should I avoid while taking guanfacine?
Guanfacine may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be alert.
Drinking alcohol can increase certain side effects of guanfacine.
Guanfacine side effects
Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.
Call your doctor at once if you have:
chest pain, fast or slow heartbeats; or
a light-headed feeling, like you might pass out;
Common side effects may include:
mild dizziness or drowsiness;
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
See also: Side effects (in more detail)
Guanfacine dosing information
Usual Adult Dose for Hypertension:
Initial dose: 1 mg orally once a day at bedtime, when given alone or in combination with another antihypertensive drug.
Maintenance dose: 1 to 3 mg orally once a day at bedtime.
Usual Pediatric Dose for Attention Deficit Disorder:
Only the guanfacine extended-release formulation is indicated for ADHD.
Children 6 to 17 years of age:
Initial dose: 1 mg extended-release orally once a day in the morning
Dosage should be adjusted in increments of no more than 1 mg/week.
Maintenance dose: 1 to 4 mg extended-release orally once daily in the morning, depending on clinical response and tolerability.
What other drugs will affect guanfacine?
Taking this medicine with other drugs that make you sleepy or slow your breathing can worsen these effects. Ask your doctor before taking guanfacine with a sleeping pill, narcotic pain medicine, muscle relaxer, or medicine for anxiety, depression, or seizures.
Other drugs may interact with guanfacine, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell each of your health care providers about all medicines you use now and any medicine you start or stop using.
More about guanfacine
Related treatment guides
Where can I get more information?
- Your pharmacist can provide more information about guanfacine.
- 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.
- Disclaimer: Every effort has been made to ensure that the information provided by Cerner Multum, Inc. ('Multum') is accurate, up-to-date, and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. Multum information has been compiled for use by healthcare practitioners and consumers in the United States and therefore Multum does not warrant that uses outside of the United States are appropriate, unless specifically indicated otherwise. Multum's drug information does not endorse drugs, diagnose patients or recommend therapy. Multum's drug information is an informational resource designed to assist licensed healthcare practitioners in caring for their patients and/or to serve consumers viewing this service as a supplement to, and not a substitute for, the expertise, skill, knowledge and judgment of healthcare practitioners. The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug or drug combination is safe, effective or appropriate for any given patient. Multum does not assume any responsibility for any aspect of healthcare administered with the aid of information Multum provides. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse or pharmacist.
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