Highlights
- Guanfacine and clonidine are both alpha-2 agonist medications that work to lower blood pressure. In their extended-release form, they’re approved to treat attention deficit hyperactivity disorder (ADHD) in children and adolescents aged 6 to 17.
- These two medications are very similar and are used for the same purposes, but have some differences, including mechanism of action and dosage.
- Guanfacine and clonidine are best used in conjunction with other ADHD treatment methods like behavior therapy.
If you live with attention deficit hyperactivity disorder (ADHD), then you may already know that stimulant medication (like Ritalin or Adderall) is an effective treatment to help you manage your symptoms. However, many people can’t or don’t want to take stimulants for various reasons. You might not like the side effects, or you may not want to risk the potential for abuse and addiction.
Fortunately, there are non-stimulant medications available to treat ADHD. Guanfacine and clonidine, sold under the brand names Intuniv and Kapvay, are two non-stimulant medications that are FDA-approved to treat ADHD in children and adolescents, and research suggests they could be helpful for adults with ADHD as well.
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 types of 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 key symptoms of ADHD. This also helps to lower blood pressure.
Extended-release guanfacine and clonidine may also be used off-label to treat anxiety disorders, post-traumatic stress disorder, and tic disorder.
These medications share many similarities. Both guanfacine and clonidine are non-stimulant options used to treat attention deficit hyperactivity disorder. Both of them are only FDA-approved to treat children and adolescents. However, healthcare providers can prescribe any of these for adults with ADHD if it’s deemed appropriate based on the assessment.
|
Brand name |
Intuniv / Tenex |
Kapvay / Catapres / Onyda |
|
What is the generic drug? |
Guanfacine |
Clonidine |
|
What forms does it come in? |
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? |
1mg, 2mg (Tenex) 1mg, 2mg, 3mg, 4mg (Intuniv) |
0.1mg, 0.2mg, 0.3mg (Catapres) 0.1mg, 0.2mg (Kapvay) |
|
Who can take it? |
6 to 17 years olds with ADHD; adults with high blood pressure; may have other off-label uses |
6 to 17 years olds with ADHD; adults with high blood pressure; may have other off-label uses |
|
What is the dosage? |
Starts at 1 mg per day |
Starts at 1 mg per day |
|
What is the typical length of treatment? |
Long-term |
Long-term |
|
How do I store this medication? |
At room temperature in an air-tight container |
At room temperature in an air-tight container |
|
Is there a risk of withdrawal from this medication? |
Yes |
Yes |
Note that the dosages are provided for informational purposes only. Always consult with your healthcare provider to determine the most appropriate dosage individually.
An Overview of Guanfacine
Guanfacine extended-release tablets, sold under the brand name Intuniv, are used to treat ADHD. Researchers still don’t understand exactly how guanfacine works to reduce ADHD but it’s been shown to reduce its symptoms like inattention, restlessness, and impulsivity in children and teens.
Extended-release guanfacine (Intuniv) is only FDA-approved to treat ADHD in children and adolescents 6 to 17 years old. This is because we don’t yet have enough research showing that it’s helpful for ADHD in adults. But because immediate-release guanfacine (under the brand name Tenex) is approved to treat high blood pressure in adults, many physicians prescribe it “off-label” for adults with ADHD.
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
- Neonatal opioid withdrawal syndrome
Clonidine vs Guanfacine for ADHD
Both extended-release clonidine (Kapvay) and extended-release guanfacine (Intuniv) have been
Some studies have also found that guanfacine for ADHD has unique benefits that clonidine may not have, like improving planning and working memory.
Although these medications haven’t been approved for adult ADHD, research suggests that it could be helpful. For example, one
Both medications have been found to be effective for treating ADHD. However, neither of them are as effective as stimulant medications. Stimulants can also come with a risk of addiction and abuse as well as more severe side effects. This is why some people may prefer to take alpha agonists like guanfacine or clonidine for ADHD.
Clonidine vs Guanfacine for Anxiety
Clonidine, especially in its immediate-release form, has shown some efficacy in reducing anxiety in acute settings, such as with PTSD. However, both clonidine and guanfacine can only be prescribed for anxiety off-label, so other medications like benzodiazepines and SSRIs are more commonly used as first-line treatments. Some studies have found that clonidine, including in its immediate-release form as Catapres,
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 and anxiety. However, it’s important to consider that neither clonidine nor guanfacine are 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 treatments available, including benzodiazepines like Xanax and antidepressants like Paxil.
Side Effects
Both guanfacine and clonidine can come with side effects. However, one of the reasons that people may choose to take these medications over stimulants is that they may come with fewer or less intense side effects.
The side effects of these medicines are similar, since they’re the same class of medication. Here are some of the most common ones, along with the percentage of people each affects.
|
Side effect |
Guanfacine |
Clonidine |
|
Drowsiness |
Yes (38%) |
Yes (38%) |
|
Headache |
Yes (24%) |
Yes (20%) |
|
Fatigue |
Yes (14%) |
Yes (16%) |
|
Abdominal pain |
Yes (11%) |
Yes (15%) |
|
Dizziness |
Yes (8%) |
Yes (7%) |
|
Dry mouth |
Yes (2%) |
Yes (5%)* |
|
Constipation |
Yes (3%) |
Yes (6%)* |
|
Irritability |
Yes (6%) |
Yes (9%) |
|
Decreased appetite |
Yes (5%) |
Yes (4%) |
|
Sleep terrors |
No |
Yes (3%) |
|
Nausea |
Yes (5%) |
Yes (5%) |
|
Diarrhea |
Yes (4%) |
No |
|
Nightmares |
No |
Yes (9%)* |
|
Tearfulness |
No |
Yes (3%)* |
|
Poor quality sleep |
No |
Yes (3%) |
*Only at .04mg/day
[Source:
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.
|
Medication |
Guanfacine |
Clonidine |
|
CYP3A4 inhibitors, including grapefruit juice |
X |
X |
|
Central nervous system depressants |
X |
X |
|
Blood pressure medications |
X |
X |
|
Beta blockers |
X |
X |
|
Tricyclic antidepressants |
X |
X |
|
CYP3A4 inducers, including St. John’s Wort |
X |
X |
Can You Take Clonidine and Guanfacine Together?
You should never take clonidine and guanfacine 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. You should only take one or the other, and one can’t be replaced with the other. If you want to change your medication, talk to your healthcare provider.
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.
Is Guanfacine or Clonidine Right for You?
Guanfacine and clonidine could both be good options to help you manage your ADHD and anxiety symptoms, especially if stimulant medications haven’t worked for you. Talk to your healthcare provider about these medications to learn what treatment is the most suitable for you. The ADHD providers at MEDvidi can recommend the right option for you based on your symptoms and medical history.
FAQ
Why is guanfacine not given to adults?
Many physicians prescribe Intuniv off-label to treat adult ADHD and anxiety. Extended-release guanfacine (Intuniv) isn’t yet FDA-approved to treat ADHD in adults because there’s no research that says it’s effective. There are also more ADHD medication options for adults that are effective. But its immediate-release form (Tenex) is approved for adults with high blood pressure.
Does guanfacine calm you down?
Is guanfacine or clonidine better for sleep?
Does clonidine work immediately for ADHD?
Can I switch from clonidine to guanfacine?
It’s possible to switch from clonidine to guanfacine, but not on your own. Under the supervision of a healthcare provider, you can slowly taper down on clonidine and start guanfacine. Stopping clonidine or guanfacine suddenly is dangerous and can lead to rebound hypertension (a sudden spike in blood pressure).
