Clonidine as a Medication Choice for ADHD

Catapres (clonidine) is a medication that was originally approved to treat people with high blood pressure. However, because of the calming effect it has on the body, clonidine has been found to help people with attention-deficit/hyperactivity disorder (ADHD) symptoms like hyperactivity, impulsivity, aggression, overarousal, and sleep difficulties.

The Food and Drug Administration (FDA) has also approved Kapvay, the extended-release version of clonidine, as a medication for children with ADHD ages 6 and up. It can be taken alone or along with stimulant medication.

Stimulants vs. Non-Stimulants 

ADHD medications are generally categorized as either stimulants or non-stimulants. Clonidine, which is part of the class of drugs known as centrally acting alpha-agonist hypotensive agents, is considered a non-stimulant treatment for ADHD.

Stimulants, also called psychostimulants, are generally the first choice of medications used to treat ADHD. They're the most prescribed ADHD medications because they offer the most effective way to reduce symptoms like impulsivity, hyperactivity, and inattentiveness. There are two types of stimulant medications for ADHD: 

• Amphetamines (such as Adderall, Vyvanse, and Dexedrine)
• Methylphenidates (such as Ritalin, Concerta, and Methylin)

Non-stimulant medications are usually prescribed if a person with ADHD can't tolerate stimulant medication because of severe side effects. Some health conditions also prevent the use of stimulants, such as certain psychiatric disorders, sleep disorders, cardiovascular disease, or a history of stimulant misuse.

Strattera (atomoxetine), the antidepressant medication Wellbutrin (bupropion), and Qelbree (viloxazine, which was approved by the FDA in 2021) are examples of other non-stimulant medications. The antihypertensive drug called Intuniv (guanfacine) is another.

How Stimulants Work

Stimulant ADHD medications work by causing more dopamine and norepinephrine to be available in the synapses of the brain. This stimulates the central nervous system and improves cognitive functioning. Because the nervous system is stimulated, some people report feeling jittery, anxious, and on edge when they take a stimulant medication.

How Clonidine Works

Clonidine causes your brain to send signals to your blood vessels to relax them, lowering your blood pressure. In addition, clonidine impacts norepinephrine in the prefrontal cortex area of your brain. This is the place where your brain’s executive functions occur, such as planning, organizing, and using information and experiences. These effects allow you to be physically calm, yet mentally focused.

Pros and Cons of Clonidine

Pros

Clonidine has some advantages that make it helpful for people with ADHD, especially children.

• Can boost the effects of stimulants: Clonidine can be prescribed in addition to a stimulant medication, and it often enhances the effectiveness of the stimulant.
• No appetite effect: Clonidine is appetite neutral, which means it doesn't increase or decrease appetite. Stimulants often suppress appetite, which can be a problem for people who are already underweight.
• Effective for kids: A meta-analysis of 73 studies looked at the efficacy of six different ADHD medications for kids 6 to 18 years old. Among the three non-stimulants included, clonidine was found to be the most effective and the most tolerable when compared with atomoxetine and extended-release guanfacine. (Wellbutrin was left out due to lack of evidence.)
• Reduces anxiety: People who have ADHD often experience anxiety as well. Medication from the benzodiazepine family, such as Xanax (alprazolam) or Valium (diazepam), is often prescribed for anxiety. However, these can be habit-forming and can negatively affect cognitive functions like attention. For this reason, clonidine is often prescribed to help people with ADHD who have anxiety.
• Helps with sleep difficulties: Sleep problems are another issue many people with ADHD face. A potentially positive effect of taking clonidine is that it can help improve sleep. In fact, some doctors prescribe a low dose of clonidine off-label (this means using an FDA-approved drug for an unapproved use) to help with sleep.
• Not addictive: While traditional stimulant medications might be avoided because they can be habit-forming, clonidine is not considered to be addictive.
• Reduces blood pressure: If you have ADHD and high blood pressure, clonidine may be a good choice for you because it will also help reduce your blood pressure.
• Can treat tic disorders: If you have both Tourette syndrome or another tic disorder and ADHD, clonidine can help the symptoms of both.

Cons

Clonidine is not suitable for everyone. It has some disadvantages that you should know about if you are considering taking clonidine.

• Doesn't help all ADHD presentations: Clonidine helps with hyperactivity, impulsivity, aggression, overarousal, and sleep difficulties. However, it hasn't been found to be as helpful for inattentive symptoms of ADHD.
• Little research on adults with ADHD: Studies have shown that clonidine can help ADHD symptoms in children and adolescents, but clonidine is not typically prescribed for adult ADHD. This could be because the symptoms that clonidine helps the most, such as aggression, hyperactivity, and impulsivity, often diminish in adulthood.
• Less effective than stimulants: Clonidine isn't as effective as stimulant medications for treating ADHD symptoms. However, its effects are significant enough for the FDA to approve its use for ADHD.
• May cause brain fog: Rather than increasing the ability to focus, some people find clonidine reduces their focus or causes brain fog. Problems with the ability to focus can be temporary as your body adjusts to the clonidine. However, some people find this problem continues.
• May cause drowsiness: While clonidine can help with nighttime sleep problems, some people who take clonidine also feel fatigued or sedated during the daytime. This can have negative effects on school or work performance. Sometimes, the sleepiness decreases with time. This is an important side effect to discuss with your doctor, as it has the potential to be dangerous if you drive a vehicle or operate machinery.
• May cause erectile dysfunction (ED): A drawback for men taking clonidine is ED. Even though you might feel embarrassed to talk to your doctor about ED, they will be aware that this is a possible side effect and will want to help you resolve the issue.

Forms and Dosage

When clonidine is first prescribed, it's usually at the lowest dose. This may be 0.05 to 0.1 milligrams (mg) to start. Your doctor gradually increases the dose until the effective (therapeutic) dose is found. Catapres tablets come in 0.1mg, 0.2mg, and 0.3mg. Kapvay is the extended-release version, and it's available in 0.1mg.

Once the therapeutic dose has been found using tablets, using a clonidine patch is an option. It may take a few weeks to see the full effects of clonidine on ADHD symptoms, but you may see some improvement sooner.

Side Effects of Clonidine

These side effects often go away after you've taken the medication for a while, but if they don't or they're bothersome, talk to your doctor:

• Behavior problems
• Constipation
• Dizziness
• Dry mouth
• Erectile dysfunction
• Fatigue
• Headache
• Irritability
• Low blood pressure
• Nausea
• Upper abdominal pain
• Vomiting

Rare But Serious Side Effects

If you experience these or any other unusual or persistent side effects, contact your doctor as soon as possible:

• Difficulty breathing
• Hallucinations
• Hives
• Hoarseness
• Irregular heartbeat
• Rash
• Slow heart rate
• Swelling anywhere in the body

Precautions When Taking Clonidine

If you have a history of low blood pressure, you may be more likely to feel dizzy, lightheaded, and nauseous while taking clonidine.

Many people forget to take their medication. If you miss a dose of clonidine, don't take a double dose as it could lower your blood pressure too much.

It's important that you don't stop taking clonidine abruptly, as this may cause rebound high blood pressure. Instead, your dose should be decreased gradually. Your doctor can give you advice on the best tapering schedule.

A Word From Verywell

While clonidine is not usually the first choice of treatment for ADHD, it can be helpful for some people, either alone or combined with another medication. If you're interested in clonidine as a treatment option, talk to your doctor. They will help you decide if it's the right choice for you.