Guanfacine oral tablets side effects: A detailed guide

Specifically, the Food and Drug Administration (FDA) has approved:

• guanfacine oral tablet* to treat high blood pressure in adults and some children
• guanfacine ER oral tablet† to treat attention deficit hyperactivity disorder in some children

This article describes possible side effects of guanfacine oral tablet and guanfacine ER oral tablet. You’ll also find information on cost savings and coupon options for guanfacine.

You can explore this overview article to learn more about guanfacine oral tablet, including the drug’s uses, side effects, ways to save on cost, and more. To learn more about guanfacine ER oral tablet, see this article.

Guanfacine oral tablet is a generic medication. It isn’t available in a brand-name version. Guanfacine ER oral tablet is a generic version of the brand-name drug Intuniv.

* Guanfacine oral tablet is formulated for immediate release (IR).
† Guanfacine ER oral tablet has an extended release (ER) effect.

More common side effects of guanfacine

Below are some of the more common side effects of guanfacine oral tablets that occurred during the drug’s studies. The more common side effects varied based on the type of guanfacine oral tablet taken.

More common side effects reported by people taking guanfacine oral tablet for high blood pressure include:

• dry mouth
• drowsiness (sleepiness)
• weakness
• dizziness
• headache

More common side effects reported by people taking guanfacine extended release (ER) oral tablet for attention deficit hyperactivity disorder include:

• drowsiness (sleepiness)
• fatigue (low energy)
• low blood pressure*
• dizziness
• nausea

* To learn more about this side effect, see the “Side effects of guanfacine in detail” section below.

Mild side effects of guanfacine

Guanfacine may cause certain mild side effects. Most often, mild side effects are temporary and can be easily managed. Tell your doctor or pharmacist if you have side effects that don’t go away or become bothersome.

Mild side effects that occurred in studies of guanfacine oral tablet and guanfacine extended release (ER) oral tablet include:

• dry mouth
• drowsiness (sleepiness)
• weakness
• dizziness
• headache
• constipation
• fatigue (low energy)
• insomnia (trouble sleeping)
• nausea
• mild allergic reaction*

Additional mild side effects reported with guanfacine ER oral tablet include:

• abdominal pain
• loss of appetite
• irritability
• inability to control your bladder
• vomiting

* To learn more about this side effect, see the “Side effects of guanfacine in detail” section below.

Serious side effects of guanfacine

Guanfacine may cause certain serious side effects. If you have any serious side effects from guanfacine oral tablets, call your doctor right away. But if you think you’re having a medical emergency or your side effects feel life threatening, take immediate action. Call 911 or a local emergency number, or go to the nearest emergency room.

After the Food and Drug Administration (FDA) approves a drug, it tracks and reviews side effects of the medication. Visit MedWatch’s website if you’d like to notify the FDA about a side effect you’ve had with guanfacine.

Serious side effects that occurred in studies of guanfacine oral tablet and guanfacine extended release (ER) oral tablet include:

• abnormal dreams or nightmares
• depression
• erectile dysfunction
• slow heart rate
• skin rash with peeling skin
• low blood pressure*
• severe drowsiness or dizziness*
• withdrawal side effects*
• severe allergic reaction*

* To learn more about this side effect, see the “Side effects of guanfacine in detail” section below.

Common questions about side effects of guanfacine

Here are answers to some common questions about side effects of guanfacine oral tablets. If you have other questions, talk with your doctor or pharmacist.

Is withdrawal a possible side effect of guanfacine?

Yes, withdrawal is a possible side effect of guanfacine. “Withdrawal” refers to symptoms that begin after you stop taking a drug.

To learn more, see the “Side effects of guanfacine in detail” section in this article. You can also talk with your doctor or pharmacist.

Does guanfacine cause long-term side effects?

Yes, sometimes, guanfacine oral tablets may cause long-term side effects. These can last for a while after you’ve stopped taking the drug.

Examples of long-term side effects reported in studies of guanfacine oral tablet and guanfacine extended release (ER) oral tablet include withdrawal side effects.

To learn more about this side effect, see the “Side effects of guanfacine in detail” section below. Also, talk with your doctor to learn more about these side effects and how to manage them. Ask them for more information about how long side effects of guanfacine may last.

How long do side effects of guanfacine typically last?

It varies. But in most cases, side effects caused by guanfacine usually only last a few hours or days before going away on their own.

That said, it’s possible to have side effects that bother you or don’t go away. Talk with your doctor if you experience this while taking guanfacine. Your doctor can review your symptoms and recommend appropriate treatment. This may include stopping guanfacine and exploring other treatment options.

Coupon for guanfacine

Visit these pages to access Optum Perks coupons and get price estimates for Guanfacine when you use the coupons. These coupons can provide significant savings on your prescription costs. 

• guanfacine oral tablet
• guanfacine extended release (ER) oral tablet

Note: Optum Perks coupons cannot be used with insurance copays or benefits.

Side effects of guanfacine in detail

Below, you’ll find details on some of the side effects of guanfacine oral tablets.

Low blood pressure

In studies, low blood pressure was rare in people taking guanfacine oral tablets. This side effect is usually mild, but may also be serious.

Low blood pressure was reported in studies of guanfacine oral tablet and guanfacine extended release (ER) oral tablet. It was more common in people taking guanfacine ER oral tablet.

With mild low blood pressure, you may not experience symptoms. But more severe cases may cause symptoms such as dizziness, fatigue, and clammy skin. You may also experience orthostatic hypotension, which is low blood pressure when you stand or sit up. This can lead to fainting.

Certain factors can increase the risk of low blood pressure with guanfacine oral tablets. These include:

• dehydration (low fluid level in your body)
• taking other drugs that lower blood pressure
• heart disease
• having a slow heart rate
• chronic kidney disease

Ways to manage

If you experience symptoms of low blood pressure, tell your doctor. They’ll likely recommend lowering your guanfacine dosage. Or they may suggest you stop taking guanfacine and recommend other treatments for your condition.

Severe drowsiness or dizziness

Severe drowsiness or dizziness were rare in studies of people taking guanfacine oral tablet or guanfacine ER oral tablet. These side effects may be serious. Severe drowsiness can slow your reaction times and impact your ability to make decisions. Severe dizziness could lead to falling, which can lead to broken bones or other injuries.

Certain factors can increase the risk of severe drowsiness or dizziness with guanfacine oral tablets. These include taking other medications that can cause these side effects together with guanfacine. Examples include benzodiazepine drugs such as alprazolam (Xanax).

Ways to manage

If you experience symptoms of severe drowsiness or dizziness, tell your doctor. They’ll likely recommend stopping treatment with guanfacine, and they can review other treatments for your condition with you.

Withdrawal side effects

In studies, withdrawal side effects were rare in people taking guanfacine oral tablet or guanfacine ER oral tablet. These side effects may be serious.

With withdrawal side effects, you have adverse reactions after suddenly stopping taking a drug. With guanfacine, withdrawal side effects may include nervousness, anxiety, and increased blood pressure.

Ways to manage

If you’re interested in stopping treatment with guanfacine, tell your doctor. They’ll likely recommend slowly decreasing your dosage over time. This is called a drug taper, and following one can lower your risk of withdrawal side effects if you stop taking guanfacine.

Allergic reaction

For some people, guanfacine oral tablets can cause an allergic reaction. These reactions were rare in studies of guanfacine oral tablet and guanfacine extended release (ER) oral tablet.

Symptoms can be mild or serious, and they may include:

• itchiness
• skin rash
• swelling under the skin, usually affecting eyelids, lips, hands, or feet
• swelling of the mouth, tongue, or throat, which can make it hard to breathe
• flushing (temporary warmth, redness, or deepening of skin color)

Ways to manage

For mild allergic reaction symptoms, such as a mild rash, call your doctor right away. They may recommend treatments to help manage your symptoms. They’ll also let you know whether you should keep taking the medication.

For severe allergic reaction symptoms, such as swelling or trouble breathing, call 911 or your local emergency number right away. These symptoms require immediate medical care because they can become life threatening. If you’ve had a serious allergic reaction to guanfacine oral tablets, your doctor may recommend taking a different medication instead.

Warnings for guanfacine

Below are some factors you may want to discuss with your doctor before taking guanfacine oral tablets.

Warnings

It may not be safe for you to take guanfacine oral tablets if you have specific health conditions. These are sometimes called drug-condition interactions. Other things may also affect whether taking guanfacine oral tablets is a safe treatment option for you.

Before taking guanfacine oral tablet or guanfacine extended release (ER) oral tablet, tell your doctor about your health and medications you take. Things to consider include:

• heart block
• heart disease
• irregular heart rhythm, including slow heart rate
• kidney conditions, such as chronic kidney disease
• past occurrence of a stroke
• past allergic reaction to guanfacine

Guanfacine and pregnancy

It’s unknown whether you should take guanfacine oral tablets during pregnancy. If you’re planning a pregnancy or can become pregnant, talk with your doctor before taking these medications.

If your doctor prescribes guanfacine ER oral tablet for attention deficit hyperactivity disorder (ADHD) and you take this medication during pregnancy, consider joining the ADHD drug pregnancy registry. This registry helps doctors and patients learn more about the risks and benefits of certain drugs for treating ADHD when they are taken during pregnancy. You can learn more or join the registry by calling 866-961-2388 or visiting this site.

Guanfacine and breastfeeding

It’s unknown whether you can take guanfacine oral tablets safely while breastfeeding. If you’re currently breastfeeding or planning to do so, talk with your doctor before taking guanfacine oral tablet or guanfacine ER oral tablet.

Guanfacine and alcohol

Guanfacine oral tablets are known to interact with alcohol. You should avoid consuming alcohol while taking guanfacine. Drinking alcohol while taking guanfacine raises your risk of severe drowsiness and dizziness.

Ask your doctor if you have additional questions about the risks of consuming alcohol while you’re taking guanfacine oral tablet or guanfacine ER oral tablet.

What to ask your doctor

This article describes common and serious side effects of guanfacine oral tablets. If your doctor prescribes guanfacine oral tablet or guanfacine extended release (ER) oral tablet, they can discuss possible side effects with you. Let your doctor know if you have concerns or questions about treatment with either of these medications.

Here’s a list of some possible questions you may want to ask your doctor:

• Are side effects of guanfacine ER oral tablet similar to those of other medications for treating attention deficit hyperactivity disorder?
• How do side effects of guanfacine oral tablet compare with those of other medications for treating high blood pressure?
• Do any medications I take interact with guanfacine and increase my risk of side effects?
• If I have side effects from taking guanfacine oral tablet or guanfacine ER oral tablet, can you prescribe a lower dosage for me to try?

Disclaimer: Optum Perks has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.