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Overview: Clonidine is a medicine that is used to treat high blood pressure (hypertension). Clonidine works to lower your heart rate and blood pressure by relaxing the blood vessels in your body. Common side effects include drowsiness and tiredness, dry mouth, dizziness, constipation, and headache. Serious side effects are less common but can include allergic reactions or withdrawal. Clonidine is available as tablets and extended-release tablets that you take by mouth and patches that you apply to your skin.

Uses

What is clonidine used for?

Clonidine (Catapres, Nexiclon XR) is commonly used for treating high blood pressure (hypertension).

Clonidine may also be used for other conditions as determined by your healthcare provider.

For information about clonidine for ADHD, see Clonidine (Kapvay, Onyda XR).

An injectable form of clonidine is used for severe cancer pain. See Clonidine epidural for more information.

How does clonidine work (mechanism of action)?

Clonidine works to lower your heart rate and blood pressure by relaxing the blood vessels in your body. 

How is clonidine supplied (dosage forms)?

Brands and other names

  • Catapres-TTS
  • Nexiclon XR

Dosage forms and strengths

  • 0.1 mg, 0.2 mg, 0.3 mg oral tablets
  • 0.17 mg, 0.26 mg extended-release oral tablets
  • 0.1 mg/24 hours, 0.2 mg/24 hours, 0.3 mg/24 hours transdermal patches

How should I store clonidine?

Clonidine should be stored at room temperature, between 68 F to 77 F (20 C to 25 C). It can be exposed to temperatures between 59 F to 86 F (15 C to 30 C) for shorter periods of time, such as when transporting it. Store in a cool, dry place.

Side Effects

What are the most common side effects of clonidine?

The most common side effects of clonidine are listed below. Tell your healthcare provider if you have any of these side effects that bother you.

  • Dry mouth
  • Drowsiness and tiredness
  • Dizziness
  • Constipation 
  • Headache
  • Skin reactions such as redness, itching, blistering, changes in skin color, swelling, and burning (Catapres-TTS)

There may be other side effects of clonidine that are not listed here. Contact your healthcare provider if you think you are having a side effect of a medicine. In the U.S., you can report side effects to the FDA at www.fda.gov/medwatch or by calling 800-FDA-1088. In Canada, you can report side effects to Health Canada at www.health.gc.ca/medeffect or by calling 866-234-2345.

What are the serious side effects of clonidine?

While less common, the most serious side effects of clonidine are described below, along with what to do if they happen.

Severe Allergic Reactions. Clonidine may cause allergic reactions, which can be serious. Stop taking clonidine and get help right away if you have any of the following symptoms of a serious allergic reaction.

  • Breathing problems or wheezing
  • Racing heart
  • Fever or general ill feeling
  • Swollen lymph nodes
  • Swelling of the face, lips, mouth, tongue, or throat
  • Trouble swallowing or throat tightness
  • Itching, skin rash, or pale red bumps on the skin called hives
  • Nausea or vomiting
  • Dizziness, feeling lightheaded, or fainting
  • Stomach cramps
  • Joint pain

Withdrawal Reactions. If you stop clonidine suddenly, it could lead to withdrawal symptoms, such as a fast increase in blood pressure, which may be life-threatening. Do not stop taking clonidine without talking with your healthcare provider. Your healthcare provider can tell you how to stop clonidine to reduce the risk of withdrawal reactions. Call your healthcare provider right away or go to the nearest emergency room if you have any of the following serious symptoms.

  • Unusual movements, responses, or expressions
  • Headache
  • Sudden and severe mental or nervous system changes
  • An extreme increase in activity or talking
  • Confusion

Warnings & Precautions

Who should not use clonidine?

Allergies to Ingredients. People who are allergic to any of the following should not take clonidine.

  • Clonidine
  • Catapres-TTS
  • Nexiclon XR
  • Any of the ingredients in the specific product dispensed

Your pharmacist can tell you all of the ingredients in the specific clonidine products they stock.

What should I know about clonidine before using it?

Do not take clonidine unless it has been prescribed to you by a healthcare provider. Take it as prescribed.

Do not share clonidine with other people, even if they have the same condition as you. It may harm them.

Keep clonidine out of the reach of children.

Taking clonidine may cause dry eyes, especially if you wear contacts. 

Clonidine can affect your alertness or coordination. Do not drive or do other activities that require alertness or coordination until you know how clonidine affects you.

The clonidine patch should be worn for seven days. If the patch starts to loosen, place the adhesive cover on top of the patch. The adhesive cover does not have any medicine and should only be placed over the patch if the patch loosens. If the patch falls off, replace it with a new patch on a different area of your skin. Only apply the patch to the upper outer part of your arm or your chest. Do not apply to skin that is cut, burned, or hardened. Fold the sticky sides of the patch together before throwing the patch away. 

You may want to wear a medical alert bracelet if you use clonidine patches. The patch needs to be removed before defibrillation or cardioversion.

What should I tell my healthcare provider before using clonidine?

Tell your healthcare provider about all of your health conditions and any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. This will help them determine if clonidine is right for you.

In particular, make sure that you discuss any of the following.

Upcoming Medical Procedures (Catapres-TTS). Tell your healthcare provider if you have an upcoming magnetic resonance imaging (MRI) exam or procedure called cardioversion. 

Current and Past Health Conditions. Tell your healthcare provider if you have any of the following.

  • Upcoming surgery
  • Electric shock to your heart, called defibrillation
  • Kidney problems
  • Stroke
  • Heart problems, including heart attack or rhythm problems

Other Medicines and Supplements. Clonidine may interact with other medicines and supplements. Before taking clonidine, tell your healthcare provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. See the Interactions section for more details.

Pregnancy. It is not known if or how clonidine could affect pregnancy or harm an unborn baby. Tell your healthcare provider if you are or plan to become pregnant. Your healthcare provider will advise you if you should use clonidine while you are pregnant or trying to get pregnant.

Breastfeeding. Clonidine passes into breast milk. Tell your healthcare provider if you are breastfeeding or plan to breastfeed.

Interactions

Does clonidine interact with foods or drinks?

There are no known interactions between clonidine and foods or drinks.

It is unknown if drinking alcohol will affect clonidine. The risk of drowsiness and dizziness may be increased if you drink alcohol while taking clonidine.

Does clonidine interact with other medicines (drug interactions)?

Always tell your healthcare provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using.

In particular, make sure that you discuss if you are using any of the following before taking clonidine.

  • A barbiturate, such as phenobarbital, butalbital, or primidone, which is a medicine that may be used to treat insomnia, migraines, or seizures
  • A tricyclic antidepressant, such as amitriptyline, nortriptyline, or protriptyline, even if it is not used for depression
  • A calcium channel blocker, such as diltiazem (Cardizem CD and others) or verapamil (Verelan, Verelan PM), which is a medicine used for high blood pressure or other conditions
  • A beta-blocker, such as metoprolol (Lopressor, Toprol XL, and others), atenolol (Tenormin), or propranolol (Inderal LA, Innopran XL), which is a medicine that may be used for certain heart conditions or to lower blood pressure
  • An antipsychotic, which is a medicine for certain mental health conditions
  • Digoxin (Lanoxin), which is a medicine used to treat irregular heartbeat and some types of heart failure
  • Any other medicine that causes dizziness and sleepiness, such as prescription pain medicines, sleep medicines, or medicines for anxiety

This may not be a complete list of medicines that can interact with clonidine. Always check with your healthcare provider.

Does interact with other drugs you are taking?

Enter your medication into the WebMD interaction checker

Overdose/Missed Dose

What should I do if I accidentally use too much clonidine?

If you or someone else has used too much clonidine, get medical help right away, call 911, or contact a Poison Control center at 800-222-1222.

What should I do if I miss a dose of clonidine?

Try not to miss a dose of clonidine. If you miss a dose, use it as soon as you remember. If it is almost time for your next dose of a tablet, skip the missed dose and only use the next dose. Do not use double or extra doses.