Clonidine isn’t the go-to drug for attention deficit hyperactivity disorder (ADHD). Generally, stimulants such as methylphenidate (Ritalin) are used. However, stimulants may not be appropriate for people with ADHD who also have sleep disorders or other conditions that stimulants may negatively affect. For these people, clonidine may be a better option.

Clonidine is included in a class of drugs called alpha-agonist hypotensive agents. These drugs relax blood vessels to help increase your blood flow. Clonidine was first approved by the U.S. Food and Drug Administration (FDA) to treat high blood pressure.

Later, in 2010, clonidine was also FDA-approved to treat ADHD in children. Exactly how this drug helps relieve the symptoms of ADHD is not known. However, it’s believed that clonidine may help balance the activity of certain brain receptors. This may help reduce hyperactivity and impulsivity.

Doctors call clonidine a third-line agent for ADHD. That is, it’s not considered as effective as stimulants and antidepressants. It may not be the best choice to treat the inattentive form of ADHD.

However, clonidine has been used as an option for people whose ADHD symptoms weren’t relieved after using stimulants or antidepressants. Clonidine may also be an option for people can’t tolerate the side effects of first-line and second-line ADHD drugs, such as people with sleep disorders, cardiovascular disease, or psychiatric disorders.

Clonidine is available as a tablet or a patch. Typically, doctors prescribe the clonidine tablets so that they can adjust the dosage easily as needed. Your doctor will most likely prescribe the lowest dose to start. You will take it at bedtime. Within two to three weeks of starting medication, you should start to notice improvement of your ADHD symptoms.

When your doctor thinks that your dosage is at its most effective level, they may talk to you about using the clonidine skin patch. It may be a more convenient option because it only needs to be changed every 7 days.

Clonidine isn’t associated with side effects such as irritability and lack of appetite that occur with stimulant drugs used to treat ADHD. However, side effects of clonidine that are fairly common include:

  • fatigue
  • headache
  • dizziness
  • dry mouth
  • constipation

More severe side effects of clonidine include:

  • irregular heart rhythm
  • slow heart rate
  • hallucinations (seeing or hearing things that aren’t real)
  • nightmares

Most likely, clonidine won’t be the first drug your doctor prescribes for your ADHD. But it’s helpful to know about all of your options. Talk to your doctor if you have other conditions that may be complicated by the side effects of stimulants. If you already take stimulant drugs and find the side effects bothersome, let your doctor know. Clonidine may be an option for you.