Clonidine as a Medication Choice for ADHD

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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 ADHD symptoms like hyperactivity, impulsivity, aggression, over-arousal, and sleep difficulties. In 2010, the U.S. Food and Drug Administration (FDA) approved Kapvay, the extended-release version of clonidine, as a medication for children with ADHD who are 6 to 17 years old to be taken either alone or along with a 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 line, or choice, of medications used to treat ADHD. They're the most prescribed ADHD medications because they're known to be the most effective way to reduce ADHD symptoms like impulsivity, hyperactivity, and inattentiveness. There are two types of stimulants: amphetamine types like Adderall, Vyvanse, and Dexedrine, and methylphenidates like Ritalin, Concerta, and Methylin.

Non-stimulant medications are usually prescribed if you can't tolerate stimulant medication because of severe side effects or when a health reason prevents you from being able to take a stimulant, such as having certain psychiatric disorders, sleep disorders, cardiovascular disease, or a history of stimulant abuse. Strattera (atomoxetine), the antidepressant medication Wellbutrin (bupropion), and the antihypertensive drug Intuniv (guanfacine) are examples of other non-stimulant medications.

How Stimulants Work

Stimulant ADHD medications work by causing more dopamine and norepinephrine to be available in the synapses of the brain. This increase stimulates the central nervous system and improves cognitive functioning, such as attaining information and understanding ideas. 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 works differently. Instead, it causes your brain to send signals to your blood vessels to relax them, lowering your blood pressure. In addition, clonidine releases norepinephrine into 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 calm physically, yet focused mentally.

Benefits

The benefits of clonidine include:

  • It can boost the effects of stimulants. Clonidine can be prescribed in addition to a stimulant medication, which often enhances the effectiveness of the stimulant.
  • There's no appetite effect. Clonidine is appetite neutral, which means it doesn't increase or decrease appetite. In contrast, when you take a stimulant, your appetite is often suppressed, which can be a problem for people who are already underweight.
  • Studies show that it's effective for kids. A meta-analysis of 73 studies looked at the efficacy of six different ADHD medications for kids who are 6 to 18 years old. Among the three non-stimulants included (Wellbutrin was ultimately left out due to lack of evidence), clonidine was found to be the most effective and the most tolerable when compared with atomoxetine and extended-release guanfacine.
  • It reduces anxiety. People who have ADHD often experience anxiety as well. A medication from the benzodiazepine family, such as Xanax (alprazolam) or Valium (diazepam), is often prescribed for anxiety. However, these are considered 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.
  • It 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 your 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.
  • It's not addictive. While traditional benzodiazepine sleeping medications might be avoided because they can be habit forming, clonidine is not considered to be addictive.
  • It reduces blood pressure. If you have ADHD and high blood pressure, clonidine may be a good choice for you because it will help reduce your blood pressure as it also treats your ADHD symptoms.
  • It's also used to treat Tourette syndrome and tic disorders. If you have Tourette syndrome and ADHD, clonidine can help the symptoms of both. A combination of clonidine and a stimulant medication can also be helpful for a tic disorder.

Drawbacks

The disadvantages of clonidine include:

  • It doesn't help all ADHD presentations. Clonidine helps hyperactivity, impulsivity, aggression, over-arousal, and sleep difficulties. However, it hasn't been found to be as helpful for inattentive symptoms of ADHD.
  • There's little research for how it works in adults with ADHD. Studies have shown that clonidine can help ADHD symptoms in children and adolescents, but there is little research to show the effectiveness of clonidine in adult ADHD. This could be because the symptoms that clonidine helps the most, such as aggression, hyperactivity, and impulsivity, often diminish in adulthood.
  • It's 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.
  • It 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.
  • It can make you tired. While sleeping better at night can be a positive benefit of taking clonidine, some people feel fatigued or sedated during the daytime too. This can have negative effects on school or work performance. Sometimes, the sleepiness decreases with time. This is an important side effect that your doctor should be made aware of, as it has the potential to be dangerous if you drive a vehicle or operate machinery.
  • Erectile dysfunction is a potential side effect. A drawback for men taking clonidine is erectile dysfunction (ED). Even though you might feel a little embarrassed to talk to your doctor about ED, he or she 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 to start. Working with a doctor, the dose is gradually increased until the effective (therapeutic) dose is found. Catapres tablets come in 0.1, 0.2, and 0.3 milligrams. Kapvay is the extended-release version that's approved to treat ADHD and it's available in 0.1 and 0.2 milligrams.

Clonidine is also available in patches, which last seven days. They're a good option if you tend to forget to take medication or you don't like swallowing tablets. 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.

Common Side Effects

The most common side effects of clonidine include:

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

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.

Rare Side Effects

More serious, but rare, side effects include:

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

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

Precautions

If you have a history of low blood pressure prior to taking clonidine, you may be more likely to feel dizziness, lightheadedness, and nausea when taking clonidine.

Many people forget to take their medication—if you do, a double dose should not be taken, as this 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.

Clonidine is a category C medication. This means it's a drug that may be unsafe for an unborn baby. Be sure to tell your doctor if you're pregnant, breastfeeding, or planning to become pregnant.

A Word From Verywell

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

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