Guanfacine HCL is a non-stimulant ADHD medication used to treat symptoms of attention deficit hyperactivity disorder. It is commonly used as a complementary ADD therapy alongside a stimulant.
Brand Name: Intuniv, Tenex
Medically reviewed by ADDitude’s ADHD Medical Review Panel
What is the ADHD Medication Guanfacine?
Guanfacine (Brand Name: Intuniv, Tenex) is a non-stimulant ADHD medication used to treat attention deficit hyperactivity disorder (ADHD or ADD). It is commonly used as a monotherapy, or as a complementary treatment alongside stimulant ADHD medications.
Guanfacine is a central alpha2A-adrenergic receptor agonist that is thought to affect receptors in the brain in a way that improves ADHD symptoms such as emotional sensitivity, hyperarousal, and social aggression. Non-stimulant medications like guanfacine sometimes help patients with ADHD who can’t take or don’t experience benefits from stimulants.
Guanfacine does not have a high risk of abuse or dependence. It is not a controlled substance.
The immediate-release formulation of guanfacine is used to treat high-blood pressure. Its safety has not been studied in children under age 12. The extended-release formulation has not been studied in children younger than 6.
How Is Guanfacine Used to Treat ADHD Symptoms?
Before starting or refilling a guanfacine prescription, read the medication guide included with your pills, as it may be updated with new information.
This guide should not replace a conversation with your doctor, who has a holistic view of your or your child’s medical history, other diagnoses, and other prescriptions. If you have questions, ask your doctor or pharmacist before you begin taking the medication.
What Is the Best Dosage of Guanfacine for Treating ADHD?
As with all medications, follow your guanfacine prescription instructions exactly. Guanfacine is available in two formulations:
- Immediate-Release Tablet: (Brand Name: Tenex) Taken up to twice daily. Available in 1mg or 2mg dosages.
- Extended-Release Tablet: (Guanfacine ER, Brand Name: Intuniv) Taken once daily in the morning or evening at approximately the same time each day. Tablets are available in 1mg, 2mg, 3mg, and 4mg dosages.
Guanfacine should not be taken with a high-fat meal. This can speed up the release of medication, and increase the risk of side effects. Tablets should be swallowed whole with water or other liquids, and never crushed or chewed.
The optimal dosage varies patient by patient and by the condition being treated. Your doctor may adjust your dosage weekly by 1mg increments until you or your child experiences the best response — that is, the lowest dosage at which you experience the greatest improvement in symptoms without side effects.
If you miss a dose, you should take it as soon as possible, unless it is already time for your next dose. You should not take two doses of guanfacine at the same time. Contact your doctor if you have questions about skipped pills.
Do not drink alcohol while taking this drug.
When discontinuing treatment, or decreasing dosage, patients should work with a doctor to gradually taper the level of medication by no more than 1mg every 3 to 7 days. Stopping guanfacine suddenly can create withdrawal symptoms including increased heart rate and high blood pressure, sometimes accompanied by headaches, confusion, agitation, or tremors.
What Side Effects are Associated with Guanfacine?
The most common side effects of guanfacine are as follows: sedation, tiredness, difficulty sleeping, low blood pressure, nausea, stomach pain, dizziness, dry mouth, irritability, vomiting, and slow heart rate.
Other serious side effects include low blood pressure or heart rate, fainting, sleepiness, or withdrawal symptoms. Taking guanfacine may impair your or your teenager’s ability to drive, operate machinery, or perform other potentially dangerous tasks. If side effects are bothersome, or do not go away, talk to your doctor. Most people taking this medication do not experience any of these side effects.
Report to your doctor any heart-related problems or a family history of heart and blood pressure problems. Patients with structural cardiac abnormalities, renal failure, and serious heart problems could experience complications while taking guanfacine. Physicians should monitor these vital signs closely during treatment. Call your doctor immediately if you or your child experience warning signs such as chest pain, shortness of breath, or fainting while taking guanfacine.
The above is not a complete list of potential side effects. If you notice any health changes not listed above, discuss them with your doctor or pharmacist.
What Precautions are Associated with Guanfacine?
Store guanfacine in a secure place out of the reach of children, and at room temperature. Do not share your guanfacine prescription with anyone, even another person with ADHD. Sharing prescription medication is illegal, and can cause harm.
You should not take guanfacine if you have an allergy to guanfacine or any of its ingredients. You should use caution taking guanfacine if you have kidney problems, a history of fainting, heart problems, or a history of stroke.
Avoid becoming overheated or dehydrated while taking guanfacine.
If you’re thinking of becoming a mother, discuss the use of guanfacine with your doctor. Animal studies indicate a potential risk of fetal harm. It is not known if guanfacine is passed through breastmilk, so it is recommended that mothers do not nurse while taking it.
What Interactions are Associated with Guanfacine?
Before taking guanfacine, discuss all other active prescription medications with your doctor. Guanfacine can exacerbate the drowsiness created by depressants including alcohol, barbiturates, antihistamines, or other sedatives.
Share a list of all vitamin or herbal supplements, and prescription and non-prescription medications you take with the pharmacist when you fill your prescription, and let all doctors and physicians know you are taking guanfacine before having any surgery or laboratory tests. The above is not a complete list of all possible drug interactions.
More Information on Guanfacine and Other ADHD Medications:
Tips for Good Medication and Treatment Reviews
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