What is Clonidine: Uses, Warnings & Interactions

Medically reviewed by Karen BergerPharm.D.
Licensed Pharmacist
Updated Aug 6, 2025  •  Published Dec 30, 2020
Fact Checked

Clonidine is a generic prescription medicine used to treat high blood pressure, as well as other conditions such as ADHD and cancer pain. Unlike many other blood pressure drugs, clonidine works on the central nervous system, causing a part of the brain to relax blood vessels. That’s why it has so many other uses that seem unrelated to blood pressure like ADHD and cancer pain. Doses are typically taken as oral tablets, but people can opt for a once-a-week skin patch for convenience.

Clonidine overview

BRAND NAMES:

  • Catapres, Nexiclon XR, Duraclon

Generic Names:

  • Clonidine Hcl

Uses:

  • Treats high blood pressure, ADHD (in pediatric patients), and cancer pain.

Therapeutic Classes:

  • Antihypertensive, alpha agonist, cardiovascular agent, ADHD agent, analgesic

Forms:

  • Tablet, extended-release tablet, patch, injection

How it’s taken:

  • By mouth, injection, or through the skin

What is Clonidine used for?

Clonidine lowers blood pressure in people with hypertension. The FDA has also approved clonidine extended-release tablets for use in children with attention-deficit hyperactivity disorder (ADHD). Clonidine injections are approved to help relieve cancer pain when narcotic painkillers aren’t providing enough relief. Finally, healthcare providers sometimes prescribe clonidine off-label to treat tic disorders, opioid withdrawal, and other conditions.

Key takeaways

  • Take clonidine exactly as prescribed, and do not stop taking it without guidance from your healthcare provider. Stopping this medicine suddenly can cause a dangerous spike in blood pressure.

  • Clonidine can be taken with or without food. If you take the extended-release tablets, swallow them whole and do not cut, crush, or chew the tablets.

  • If you take immediate-release clonidine tablets, it is best to take the last dose of the day at bedtime.

  • When using the clonidine patch, apply it to clean, dry, hairless skin and rotate application sites each week. Always remove the old patch before applying a new one.

  • Before taking clonidine, tell your healthcare provider about all your medical conditions and any medications, vitamins, or supplements you are taking.

What form(s) does Clonidine come in

  • Tablet

    • 0.1 mg

    • 0.2 mg

    • 0.3 mg

    • Extended-release tablet

    • 0.1 mg

    • 0.17 mg

    • Patch

    • 0.1 mg/day

    • 0.2 mg/day

    • 0.3 mg/day

    • Injection

    • 0.1 mg/mL

    • 0.5 mg/mL (requires dilution)

What are common Clonidine doses?

  • For high blood pressure: 0.1–0.3 mg immediate-release tablets taken twice per day OR 0.17–0.52 mg extended-release tablets taken once per day OR 0.1–0.3 mg/day patch applied once every 7 days

  • For ADHD (extended-release tablets): 0.1–0.4 mg per day, divided into one or two daily doses

  • For severe cancer pain: 30-40 mcg/hour epidural infusion (doses are individualized and must be gradually increased by a healthcare provider)

Common Clonidine prescriptions

  • cloNIDine HCl
    30 tablets disp pack

  • cloNIDine HCl
    0.1mg tablet

  • cloNIDine HCl
    0.2mg tablet

  • cloNIDine HCl
    0.3mg tablet

How to take Clonidine

  • Follow all directions when taking this medicine. Do not use more than directed.

  • If clonidine is being taken for high blood pressure, take the last dose of the day as close to bedtime as possible.

  • Do not stop taking clonidine until talking to the doctor. The dose may need to be tapered for a few days when the drug is discontinued.

  • How to take clonidine tablets

    • Both immediate-release and extended-release tablets can be taken with or without food.

    • Swallow extended-release clonidine tablets whole. Do not crush, break, or chew them.

    • Store clonidine tablets at room temperature in a tightly closed light-resistant container. Keep away from children and pets.

  • How to use clonidine patches

    • Your doctor will tell you how many patches to use, where to apply them, and how often to apply them. Do not use more patches or apply them more often than your doctor tells you to.

    • Read the patient instructions that come with this medicine. They will tell you the body areas where this patch can be worn. Choose different spots each time you apply a new patch.

    • When choosing a spot, do not put a new patch in the same place as the last one.

    • Remove the old patch before applying a new one.

    • Apply the patch to clean, dry skin that has very little hair or no hair. Do not put the patch over burns, cuts, or irritated skin. Do not shave just before applying the patch.

    • Clean the area with soap and water and dry the skin.

    • Leave the patch in its sealed wrapper until you are ready to put it on. 

    • Tear the wrapper and open it carefully. NEVER CUT the wrapper or the patch with scissors. Do not use any patch that has been cut by accident.

    • Leave the patch on your skin for 7 days. Do not remove the patch without your doctor's approval. 

    • Leave the patch in place even when you shower, bathe, or swim. If the patch loosens, cover it with an extra adhesive that is provided in the box.

    • Put on a new patch if the old one has fallen off and cannot be reapplied.

    • Store the patches at room temperature in their sealed wrappers in the original carton.

What to do if you miss a dose of Clonidine

  • If you forget a clonidine tablet, skip the missed dose. Take the next dose as scheduled. Do not take an extra dose to make up for a missed dose.

  • If you forget to put on a new clonidine patch, put it on when remembered. If one or two days have passed since you forgot to put on a patch, call the doctor for advice on what to do.

Clonidine contraindications

  • This medicine is not right for everyone. Before using clonidine, tell your healthcare provider about all of your medical conditions, allergies to medicines, and all the medicines you take. This includes prescription and OTC drugs, vitamins, and nutritional supplements.

  • Do not use it if you have had an allergic reaction to clonidine or any ingredient in the medicine.

Clonidine warnings

  • Tell any doctor or other healthcare provider who treats you that you are using this medicine.

  • Tell your doctor if you are pregnant or breastfeeding. Tell your doctor if you are planning to become pregnant, as clonidine can affect fertility in men and women.

  • Tell your doctor if you have:

    • Kidney disease

    • Low or high blood pressure

    • A history of fainting or passing out

    • Heart or blood vessel problems

    • A history of heart attack or stroke

    • Pheochromocytoma (adrenal gland tumor)

    • Any other health conditions

  • This medicine may make you drowsy, dizzy, or lightheaded. Do not drive or do anything that could be dangerous until you know how this medicine affects you.

  • This medicine may cause dry mouth. The prescribing doctor may have suggestions to help relieve the dryness and discomfort.

  • Clonidine transdermal patches contain aluminum. Before you have an MRI, remove the patch. Aluminum can cause skin burns at the patch site during an MRI.

  • Even if you feel well, do not stop using the medicine without asking your doctor. If you stop the drug suddenly, you may experience rebound hypertension or withdrawal symptoms. The doctor will need to slowly decrease your dose before you stop it completely.

Clonidine interactions

  • To avoid potentially hazardous drug interactions, tell the prescribing healthcare provider about all prescription drugs, over-the-counter medications, vitamins, and supplements you use before taking clonidine.

  • In particular, make sure to tell the prescribing doctor if you’re taking:

    • Other blood pressure medications

    • Any drugs that treat depression or other mental health conditions

    • Drugs that correct the heart’s rhythm or heart rate such as digoxin, calcium channel blockers, or beta blockers

    • Drugs that cause sedation or drowsiness

  • Avoid drinking alcohol while using clonidine. 

  • Tell other healthcare providers you are using this medicine before they prescribe new medications.

Clonidine side effects

Serious side effects

Call your doctor right away or get emergency medical help if you notice any signs or symptoms of a serious possible side effect, including:

  • Fast, slow, pounding, or uneven heartbeat

  • Lightheadedness, dizziness, drowsiness, or fainting

  • Chest pain, heartbeats that feel wrong, dizziness, fainting, trouble breathing, shortness of breath

  • Slow pulse, tiredness, weakness, fainting, confusion, shortness of breath

  • Depression

  • Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing

  • Allergic reaction to the clonidine patch: Skin rash, blistering, swelling, or redness where the patch is worn

Some of these symptoms—especially chest pain, difficulty breathing, severe allergic reactions, or fainting—can be medical emergencies. Do not wait to contact your doctor if symptoms are severe. Get emergency medical attention right away.

Common side effects

  • Low blood pressure

  • Dry mouth

  • Anxiety or irritability

  • Drowsiness

  • Dizziness

  • Headache

  • Stomach pain

  • Nightmares

  • Trouble sleeping

Find more detailed information about clonidine side effects here.

Medically reviewed by Karen BergerPharm.D.
Licensed Pharmacist

After receiving her doctorate from the University of Pittsburgh School of Pharmacy, Karen Berger, Pharm.D., has worked in both chain and independent community pharmacies. She currently works at an independent pharmacy in New Jersey. Dr. Berger enjoys helping patients understand medical conditions and medications—both in person as a pharmacist, and online as a medical writer and reviewer.

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