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Monica Amin, PharmD
Monica Amin joined the Marley Drug team in 2022, prior to which she held various roles in the pharmaceutical industry as a pharmacist. Monica holds a PharmD and is actively pursuing an MBA.
Apr 12, 2024

Clonidine for Hypertension and ADHD

Clonidine is a prescription medication that belongs to the class of drugs known as central alpha agonists. This group of medications primarily influences alpha-2 adrenergic receptors in the brain, which can have a wide range of effects on the body depending on the condition being treated.

Both Kapvay and Catapres contain clonidine as their active ingredient, but they are formulated differently and prescribed for different purposes. Kapvay, which comes in extended-release tablets, is approved for the treatment of ADHD.

Kapvay, which comes in extended-release (ER) tablets, is approved for the treatment of ADHD. It provides a steady effect to help manage symptoms over time. Unlike stimulant medications such as Adderall or Ritalin used for ADHD, Kapvay does not have a potential for abuse, making it a safer option for long-term use.

Catapres, on the other hand, is available in immediate-release tablets and is used for high blood pressure. Catapres is effective in quickly reducing high blood pressure levels, essential for preventing the risks associated with hypertension.

It is important to keep in mind that these medications are not interchangeable and should not be substituted for one another.

Uses

High blood pressure (Hypertension)

Clonidine treats high blood pressure by activating alpha-2 adrenergic receptors in the brain. This action reduces the secretion of norepinephrine, a hormone that increases heart rate and constricts blood vessels. As a result, clonidine helps lower heart rate and relax blood vessels, thereby promoting smoother blood flow and reducing blood pressure.

Attention deficit hyperactivity disorder (ADHD)

It is not fully understood how Clonidine works to treat ADHD, however, it is believed to play a role in attention and impulse control. The calming effect of this medication may help manage symptoms such as impulsivity, hyperactivity, and inattention in some with ADHD. It can be used in both adults and children, often in those 6 to 17 years old.

Availability

This medication is available in tablet form in dosages ranging from 0.1 mg, 0.2 mg, and 0.3 mg, taken by mouth, with or without food. Generally, it is taken 2 times a day (in the morning and at bedtime.)

The extended-release tablet is usually taken once daily at bedtime, and in some cases, twice a day, with or without food, and the tablet should be swallowed whole and not crushed, chewed, or broken.

Clonidine is also available as a transdermal patch worn on the skin under the brand name Catapres-TTS (Transdermal Therapeutic System). The patch is used for high blood pressure. The patch provides a steady, consistent release of clonidine into the bloodstream over a period of time (usually 7 days).

Discontinuation

Do not discontinue the use of Clonidine without speaking with your doctor first. Abruptly discontinuing Clonidine could result in withdrawal or "rebound" effects, including an increase in blood pressure, and may cause symptoms such as nervousness, restlessness, agitation, headaches, tremors, or shaking.

Continuing to take this medication is essential, even if you are feeling well, especially if you have high blood pressure. High blood pressure frequently presents no noticeable symptoms.

In rare cases, the withdrawal from this medication could potentially lead to stroke and even death. It is important to seek medical advice before making any changes to your Clonidine regimen.

Side Effects

Common side effects
  • Low blood pressure, dizziness, or drowsiness
  • Feeling sleepy, tired, or having low energy
  • Dry mouth
  • Decreased appetite
  • Constipation
  • Fatigue
  • Difficulty sleeping, including insomnia, or nightmares

If you are experiencing any of these side effects, talk with your healthcare provider to determine whether a dose adjustment or switching to a different medication would be beneficial for you.

Serious side effects

While Clonidine is generally well-tolerated, it may cause serious side effects in some, including the following:

  • A lightheaded feeling, like you’re going to pass out
  • Severe chest pain or shortness of breath
  • Feelings of confusion, problems understanding what is happening around you, or hallucinations
  • Heart problems such as an irregular heartbeat, heart palpitations, or an unusually slow heartbeat

If you’re experiencing any of these serious side effects, immediately call your doctor and stop taking this medication.

Warnings
  • Caution for allergies: Avoid using Clonidine if you have previously experienced an allergic reaction to either Clonidine or the patch. Taking oral clonidine after a skin reaction to the patch may result in a widespread rash, and itching, and potentially trigger a severe allergic response.
  • Surgical precaution: It is important to inform your doctor if you have a planned surgery, including dental surgery. Your doctor may require you to temporarily stop taking clonidine before your surgery.

Interactions

Clonidine may interact with certain medications or supplements. It is recommended to always inform your doctor and pharmacist about any other medications or supplements, including prescribed and over-the-counter, vitamins, and dietary or herbal supplements, that you are currently taking.

Avoid using Clonidine with medications that could increase your risk of certain side effects, such as tricyclic antidepressants, including Amitriptyline, calcium channel blockers, including Diltiazem or Verapamil, beta-blockers, including Carvedilol or Propranolol, or medications with sedative effects that could cause drowsiness, including opioids.