Generic Name: clonidine, Oral tablet

Generic Name:

clonidine, Oral tablet

Catapres

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SECTION 1 of 5

Highlights for clonidine

Oral tablet
1

Clonidine immediate-release tablets are used to reduce blood pressure.

2 3

Common side effects include headache, dizziness, sleepiness, and problems focusing your eyes.

4

Clonidine can cause dry eyes, which can make wearing contact lenses difficult.

IMPORTANT INFORMATION

Allergy warning

Don’t take oral clonidine if you’ve had an allergic reaction to clonidine or the clonidine patch in the past. Taking oral clonidine after having a skin reaction to the patch can cause a rash over your whole body, itching, and possibly a severe allergic reaction.

Surgery warning

You can take clonidine up to 4 hours before a surgery. Don’t take it within the 4 hours right before your surgery. You can restart it as soon as possible after surgery.

Drug Features

Clonidine is a prescription medication. It’s available in these forms: oral immediate-release tablet, patch, and oral extended-release tablet. The form you use may depend on your condition.

It’s also available in a generic version. Generic drugs usually cost less. In some cases they may not be available in every strength or form as the brand. Talk to your healthcare provider to see if the generic will work for you.

This drug may be used as part of a combination therapy. That means you may need to take it with other drugs.

Why It's Used

Clonidine immediate-release oral tablets are used to reduce blood pressure.

How It Works

Clonidine stimulates parts of the brain stem to lower your heart rate and blood pressure.

More Details

How It Works

Clonidine stimulates parts of the brain stem to lower your heart rate and blood pressure.

Clonidine belongs to a class of drugs called centrally acting alpha-agonists.

SECTION 2 of 5

clonidine Side Effects

Oral tablet

Most Common Side Effects

The most common side effects that occur with clonidine include:

  • dry mouth and dry eyes

  • dizziness

  • feeling drowsy and tired

  • stomach upset or pain

  • sedation

  • constipation

  • headache

Serious Side Effects

If you experience any of these serious side effects, call your doctor right away. If your symptoms are potentially life threatening or if you think you’re experiencing a medical emergency, call 9-1-1.

  • increased then decreased blood pressure

  • slower or faster heart rate

  • pounding heart

  • uneven heart rate

  • dizziness when you stand

  • passing out

  • slowed breathing or trouble breathing

  • chest pain

  • hallucinating

Pharmacist's Advice
Healthline Pharmacist Editorial Team

Clonidine is sedating. However, this effect might go away the longer you take it.

Mild side effects may go away within a few days or a couple of weeks. Talk to your doctor or pharmacist if they’re more severe or don’t go away.

Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs affect each person differently, we cannot guarantee that this information includes all possible side effects. This information is not a substitute for medical advice. Always discuss possible side effects with a healthcare provider who knows your medical history.
SECTION 3 of 5

clonidine May Interact with Other Medications

Oral tablet

Clonidine can interact with other medications, herbs, or vitamins you might be taking. That’s why your doctor should manage all of your medications carefully. If you’re curious about how this drug might interact with something else you’re taking, talk to your doctor or pharmacist.

Note: You can reduce your chances of drug interactions by having all of your prescriptions filled at the same pharmacy. That way, a pharmacist can check for possible drug interactions.

Alcohol Interaction

Combining alcohol with clonidine may cause a dangerous sedative effect. It may slow your reflexes, cause poor judgment, and cause sleepiness.

Medications That Might Interact with This Drug

Drugs that increase tiredness/sedation

Taking these drugs with clonidine might increase sedation:

  • barbiturates
    • phenobarbital
    • pentobarbital
  • phenothiazines
    • chlorpromazine
    • thioridazine
    • prochlorperazine
  • benzodiazepines
    • lorazepam
    • diazepam
  • medicines for pain (opioids)
    • oxycodone
    • hydrocodone
    • morphine
  • other sedating drugs

Don’t combine these drugs with clonidine.

Tricyclic antidepressants (TCA)

Examples are:

  • clomipramine (Anafranil)
  • desipramine (Norpramin)
  • doxepin (Sinequan)
  • imipramine (Tofranil)
  • nortriptyline (Pamelor)
  • protriptyline (Vivactil)
  • trimipramine (Surmontil)

If you’re taking clonidine for blood pressure, these drugs may cause clonidine not to lower blood pressure well. Your dose of clonidine may need to be increased.

Heart drugs

These include:

  • digoxin
  • beta blockers
  • calcium channel blockers:
    • diltiazem
    • verapamil

Combining these drugs with clonidine can slow your heart rate. This can become severe. You may need to go to the hospital or have a pacemaker.

Clonidine may not be the best medicine for you if you’re taking these medications.

Antipsychotic drugs

Examples are:

  • clozapine (Clozaril)
  • aripiprazole (Abilify)
  • quetiapine (Seroquel)

You may get dizzy or have trouble balancing when you change from lying down to sitting or from sitting to standing (orthostatic hypotension).

Blood pressure drugs

Examples are:

  • angiotensin II receptor blockers:
    • losartan
    • valsartan
    • irbesartan
  • angiotensin-converting enzyme (ACE) inhibitors
    • enalapril
    • lisinopril
  • diuretics
    • hydrochlorothiazide
    • furosemide

Combining these with clonidine may lower your blood pressure too much. Your risk of passing out may increase. 

Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs interact differently in each person, we cannot guarantee that this information includes all possible interactions. This information is not a substitute for medical advice. Always speak with your healthcare provider about possible interactions with all prescription drugs, vitamins, herbs and supplements, and over-the-counter drugs that you are taking.

People with heart problems

This includes low blood pressure, low heart rate, and heart disease. This medication decreases blood pressure and heart rate.  You may be at risk for more serious side effects if you already have low blood pressure or a low heart rate.

People who get dizzy when standing

This condition is called orthostatic hypotension. Clonidine can make this condition worse. Don’t stand up too quickly and make sure not to get dehydrated. These can increase your dizziness and risk of fainting.

People with syncope (fainting)

Clonidine can make this condition worse. Don’t stand up too quickly and make sure not to get dehydrated. These can increase your dizziness and risk of fainting.

People with eye problems

This includes dry eye syndrome and problems focusing your eyes. Clonidine may make these problems worse.

Pregnant women

Clonidine is a category C pregnancy drug. That means two things:

  1. Research in animals has shown adverse effects to the fetus when the mother takes the drug.
  2. There haven’t been enough studies done in humans to be certain how the drug might affect the fetus.

Speak with your doctor if you’re pregnant or plan to become pregnant. Clonidine should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.

Women who are nursing

Clonidine may pass into your breast milk and can cause side effects in a nursing child. Tell your doctor if you’re breastfeeding. You may need to decide whether to stop breastfeeding or stop taking clonidine.

For Seniors

This medication affects blood pressure, which may cause dizziness and increase your risk of falling. 

When to call the doctor

Tell your doctor if you’ve had emergency medical treatment for your heart or if you’ve had an injury. Your doctor may need to change your dose and make sure you don’t have a withdrawal reaction.

Allergies

Don’t use this medication if you’ve had an allergic reaction to clonidine tablets or parts of the clonidine patch in the past.

Taking oral clonidine after having a skin reaction to the clonidine patch can cause a rash over your whole body, itching, and possibly a severe allergic reaction.

A severe allergic reaction may cause:

  • trouble breathing
  • swelling of your throat or tongue
  • hives
SECTION 4 of 5

How to Take clonidine (Dosage)

Oral tablet

All possible dosages and forms may not be included here. Your dose, form, and how often you take it will depend on:

  • your age
  • the condition being treated
  • how severe your condition is
  • other medical conditions you have
  • how you react to the first dose

What Are You Taking This Medication For?

High blood pressure
Form: Oral immediate-release tablets
Strengths: 0.1 mg, 0.2 mg, and 0.3 mg
Adult Dosage (ages 18 years and older)
  • The starting dose is usually 0.1 mg taken twice a day.
  • The dose is increased every week until you achieve your blood pressure goal.
  • Another dose is 0.2–0.6 mg per day taken in 2 divided doses.
  • Taking the dose at bedtime can help decrease dry mouth and feeling drowsy.
Child Dosage (ages 0-17 years)

A safe and effective dose hasn’t been established for this age group.

Special Considerations

Seniors: Your initial dose may be lower to help prevent side effects that can increase your risk of falling.

Kidney Disease: Your starting dose may be lower. Doses may be increased based on your blood pressure.

Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs affect each person differently, we cannot guarantee that this list includes all possible dosages. This information is not a substitute for medical advice. Always to speak with your doctor or pharmacist about dosages that are right for you.
Pharmacist's Advice
Healthline Pharmacist Editorial Team

Clonidine comes with serious risks if you don't take it as prescribed.

If You Don't Take It At All or Not on Schedule

Your blood pressure may increase and put you at risk for serious heart problems.

If You Stop Suddenly

It’s important not to abruptly stop taking this drug. This can lead to a withdrawal reaction. Side effects may include:

  • headaches
  • tremors
  • rapid increase in blood pressure

What to Do If You Miss a Dose

If you miss a dose, take it as soon as you can. However, if it’s just a few hours until your next dose, skip the missed dose and take the next one on schedule.

Never try to catch up by taking two tablets at once. This could result in toxic side effects.

How to Tell If the Drug is Working

You may be able to tell if this drug is working if your blood pressure goes down.

This is a long-term medication.

Take clonidine in the morning and at bedtime

The total daily dose is split into 2 doses. Each dose is usually the same, but sometimes a higher dose is needed. If you have a higher dose, take it at bedtime.

You can cut the tablets in half

Clonidine tablets have an indented line on the tablet. You can cut these tablets in half along the line. Your pharmacist can show you how to cut the tablet evenly.

Store in room temperature: 68–77°F (20–25°C)

Keep the medication away from light and high temperature.

Note: Keep your medications away from areas where they could get wet, such as bathrooms. Store them away from moisture and damp locations.

Travel

When traveling with your medication:

  • Always carry it with you or in your carry-on bag.
  • Don’t worry about airport X-ray machines. They can’t hurt this drug.
  • You may need to show your pharmacy’s preprinted label to identify the medication. Keep the original prescription-labeled box with you when traveling.

Clinical Monitoring

Your doctor will monitor your blood pressure and heart rate while you take this medication to make sure it’s working.

Electrocardiogram or other heart tests may be done to check how your heart is working and to make sure you aren’t having side effects.

Your kidney function may be checked to see if your starting dose needs to be lower.

Insurance

Many insurance companies will require a prior authorization before they approve the prescription and pay for the brand name clonidine products.

Are There Any Alternatives?

There are other medications available to treat your condition. Some may be more suitable for you than others. Talk to your doctor about possible alternatives.

What does the pill look like?

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SECTION 5 of 5

How Much Does clonidine Cost?

Oral tablet
We've partnered with GoodRX so you can compare prices and save money on your next prescription. Check out the lowest cash prices below and enter your zip code to find the best deal near you.

Compare prices and save money on your next refill!

Lowest price for clonidine

Kroger Pharmacy $7.93
Kmart $7.93
Target $7.93
These represent the lowest cash prices for clonidine and may be lower than your insurance.

Find the lowest prices of clonidine near you

These represent the lowest cash prices for clonidine and may be lower than your insurance.

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Content developed in collaboration with University of Illinois-Chicago, Drug Information Group

Medically reviewed by Creighton University, Center for Drug Information and Evidence-Based Practice on May 18, 2015

Disclaimer: Healthline has made every effort to make certain that all information is factually correct, comprehensive, and up-to-date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or other healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.

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