Highlights
- Guanfacine and clonidine belong to the same medication class, but they are different. They are both alpha-2 agonist medications that work to lower blood pressure.
- In their extended-release form, guanfacine and clonidine are approved to treat attention-deficit hyperactivity disorder (ADHD) in children and adolescents aged 6 to 17. They are often used off-label to treat ADHD in adults particularly for hyperactive symptoms.
- For adults with ADHD and anxiety, SSRIs, SNRIs, and stimulants are better supported by evidence than clonidine or guanfacine, so talk with your healthcare provider about what fits your symptoms and history.
If you live with attention-deficit hyperactivity disorder (ADHD), stimulants are not your only treatment option. Some people benefit more from non-stimulants or non-medication treatments like talk therapy.
Guanfacine and clonidine, sold under the brand names Intuniv and Kapvay, are two types of non-stimulant ADHD medications. They are both FDA-approved to treat ADHD in children and adolescents, but they are often used off-label to treat ADHD in adults.
Learn more about how guanfacine and clonidine compare when it comes to ADHD and anxiety treatment, and how to know if these medications might be helpful for you.
Guanfacine and Clonidine: Key Features
Guanfacine and clonidine belong to the same category of medication: alpha-2 adrenergic agonists, or simply alpha agonists. In their extended-release form, they’re respectively sold under the brand names Intuniv and Kapvay.
These medications work by activating alpha-2 receptors in the brain. The activation of these receptors inhibits the release of norepinephrine, which is key in reducing both hyperactivity and impulsivity, the core symptoms of ADHD. This also helps to lower blood pressure.
These medications share many similarities. Both guanfacine and clonidine are non-stimulant options used to treat attention deficit hyperactivity disorder in children and adolescents aged 6 to 17. Sometimes they can be combined alongside other ADHD medications. Extended-release guanfacine and clonidine may also be used off-label to treat ADHD in adults, anxiety disorders, post-traumatic stress disorder, and tic disorder.
For ADHD, both guanfacine and clonidine are only FDA-approved to treat children and adolescents. They are not FDA-approved to treat ADHD in adults. However, healthcare providers can prescribe guanfacine or clonidine to adults with ADHD if it’s deemed appropriate based on the assessment.
|
Feature |
Guanfacine |
Clonidine |
|
Common brands and forms |
Extended-release tablet (Intuniv); immediate-release tablet (Tenex) |
Extended-release tablet (Kapvay); immediate-release tablet and skin patches (Catapres); oral suspension (Onyda XR) |
|
What strengths does it come in? |
1 mg, 2 mg (Tenex) 1 mg, 2 mg, 3 mg, 4 mg (Intuniv) |
0.1 mg, 0.2 mg, 0.3 mg (Catapres) 0.1 mg, 0.2 mg (Kapvay) |
|
When may it be prescribed? |
6 to 17-year-olds with ADHD; adults with high blood pressure; can be prescribed off-label to adults with ADHD or anxiety |
|
|
How does it work? |
Selectively affects the alpha-2A receptor |
Broadly affects all alpha-2 receptors equally |
|
What is the typical starting dosage? |
Usually starts at 1 mg per day (Tenex, Intuniv) |
Usually starts at 0.1 mg per day (Kapvay, Onyda); 0.2 mg per day (Catapres) |
|
How long does one dose last? |
10 to 30 hours (IR, XR) |
12 to 16 hours (XR); 6 to 12 hours (IR) |
|
Is there a risk of withdrawal from this medication? |
Yes |
|
|
Does it come with side effects? |
Yes. There are fewer reported side effects with guanfacine than with clonidine, however, individual responses vary. |
|
Note that the dosages are provided for informational purposes only. Always consult with your clinician to determine the most appropriate dosage individually.
An Overview of Guanfacine
Guanfacine extended-release tablets, sold under the brand name Intuniv, are FDA-approved to treat ADHD in children and adolescents 6 to 17 years old. However, there is limited supporting data for its use in adults.. Some clinicians may prescribe it “off-label” for adults depending on the patient’s presentation and unique history.
Guanfacine can also be used off-label for anxiety disorders, post-traumatic stress disorder (PTSD), and tic disorder.
An Overview of Clonidine
Like guanfacine,
The extended-release form of clonidine, Kapvay, is used to treat ADHD symptoms in children and adolescents aged 6 to 17. Researchers don’t fully understand how Kapvay works for ADHD, but it’s theorized that it affects the area of the brain, called the prefrontal cortex, that’s implicated in ADHD. Kapvay has been found to reduce symptoms like hyperactivity and impulsivity.
On top of treating ADHD in young people and reducing blood pressure, clonidine is also FDA-approved to treat tic disorder, cancer-related pain, and neonatal opioid withdrawal syndrome.
Clonidine vs Guanfacine for ADHD
Both extended-release clonidine (Kapvay) and extended-release guanfacine (Intuniv) have been
One key difference is in the brain receptors that each medication interacts with.
Both medications can be helpful for ADHD in children and teens, but some people find that guanfacine comes with fewer side effects, for example, it may cause less drowsiness. Guanfacine also tends to last longer than clonidine because it has a longer half-life.
Some studies have also found that guanfacine for ADHD has unique benefits that clonidine may not have, like improving planning and working memory.
Some adult research is emerging –
Clonidine vs Guanfacine for Anxiety
Both clonidine and guanfacine can also be used off-label to treat anxiety; neither is objectively “preferred” than the other as SSRIs, SNRIs, and therapy have stronger evidence and are typically worth exploring first.
In simple terms, clonidine and guanfacine may help calm down the body’s “fight-or-flight” response by reducing the activity of certain nerves in the brain that control stress. They may be among medications prescribed for ADHD and anxiety when it’s deemed clinically appropriate.
However, it’s important to consider that neither clonidine nor guanfacine is considered a first-line treatment for anxiety disorders. They are sometimes prescribed off-label for anxiety and should be used only when clinically appropriate. There may be more effective, FDA-approved treatments available for anxiety, including antidepressants (SSRIs) like sertraline, fluoxetine, or, in certain cases, (SNRIs) like venlafaxine or duloxetine.
Side Effects
If you and your healthcare provider are considering adding guanfacine or clonidine to your treatment plan based on your specific needs for ADHD and anxiety, it’s a decision worth making carefully — both medications can come with side effects.
The side effects of guanfacine and clonidine are similar, since they belong to the same medication class. Here are some of the most common ones, along with how frequently they occur.
|
Side effect |
Clonidine (0.2 mg/day, 0.4 mg/day) |
|
|
Drowsiness |
Yes (38%) |
Yes (38%, 31%) |
|
Headache |
Yes (24%) |
Yes (20%, 13%) |
|
Fatigue |
Yes (14%) |
Yes (16%, 5%) |
|
Abdominal pain |
Yes (11%) |
Yes (15%, 10%) |
|
Dizziness |
Yes (6%) |
Yes (7%) |
|
Dry mouth |
Yes (4%) |
Yes (7%, 3%) |
|
Constipation |
Yes (3%) |
Yes (1%, 6%) |
|
Irritability |
Yes (6%) |
Yes (9%) |
|
Decreased appetite |
Yes (5%) |
Yes (3%, 4%) |
|
Nightmare |
|
Yes (4%, 9%) |
|
Nausea |
Yes (6%) |
Yes (4%, 5%) |
|
Diarrhea |
Yes (4%) |
No |
|
Tearfulness |
No |
Yes (1%, 3%) |
Because they’re blood pressure medications, both clonidine and guanfacine can cause low blood pressure and low heart rate. This isn’t considered a side effect, but an intended effect of the medication. If you already experience low blood pressure, your clinician may recommend other treatment options.
Drug Interactions
Because guanfacine and clonidine belong to the same category of medications, they interact with other substances in similar ways. If you’re taking another medication or supplement, even if it’s over-the-counter, let your healthcare provider know. They can help you make necessary dosage adjustments or prescribe a different medication when necessary.
In addition, other types of medications can have dangerous interactions with guanfacine and clonidine, which can cause certain side effects, including dizziness and low heart rate. They can also make one or the other of the medications less effective.
Medications and other substances that can interact with guanfacine:
- CYP3A4 inhibitors, including grapefruit juice
- CYP3A4 inducers, including St. John’s Wort
Medications and other substances that can interact with clonidine:
- Tricyclic antidepressants
- Blood pressure medications
- Central nervous system depressants
- Medications that affect sinus node function or AV node conduction, such as beta-blockers
Can You Take Clonidine and Guanfacine Together?
Clonidine and guanfacine are generally not prescribed together. Both of these medications slow your heart rate, so taking them together can cause such a slow heart rate that you face dangerous or life-threatening consequences. If you are taking one of these medications and have been prescribed the other, talk to your clinician before taking them.
In addition, clonidine and guanfacine are not interchangeable. You cannot simply replace one medication with another at the same dosage. Never use them interchangeably without medical supervision.
If you want to change your medication, talk to your healthcare provider. It’s possible to safely switch from guanfacine to clonidine (or vice versa), but it should be deemed medically appropriate and needs to be supervised by your clinician.
What to Know Before Taking Clonidine or Guanfacine
Both are hypotensive medications, which means they lower blood pressure. If you have a history of low blood pressure, then they may not be right for you. Some of the more serious warnings and adverse effects that can come along include:
- Excessive drowsiness
- Fainting
- Low blood pressure or heart rate
- Allergic reactions
In addition, if you stop taking guanfacine or clonidine suddenly, it can lead to rebound hypertension, or a spike in your blood pressure. Never stop taking these medications without your healthcare provider’s approval.
Summing Up: Is Guanfacine or Clonidine Right for You?
There’s no single “right” answer on whether guanfacine or clonidine is the better choice for ADHD or anxiety, since neither has strong evidence in adults. They may be worth discussing with your provider if first-line treatments haven’t worked or aren’t well tolerated, but the decision is highly individualized.Book your online appointment for ADHD assessment and treatment at MEDvidi; talk to a licensed clinician and learn what treatment is the most suitable for you based on your symptoms and medical history.
FAQs
Why is guanfacine not given to adults?
Extended-release guanfacine (Intuniv) may be prescribed off-label to adults with ADHD and anxiety. However, there are also other, FDA-approved ADHD medication options for adults that are proven effective. The immediate-release form of guanfacine (Tenex) is approved for adults with high blood pressure.
