What is clonidine?

Clonidine is used to treat hypertension (high blood pressure). It is sometimes used together with other blood pressure medications.

Although not approved by the FDA for these purposes, clonidine has also been used to relieve alcohol withdrawal, as an aid in methadone and opiate detoxification, as an aid in quitting smoking, to treat diabetic diarrhea, to treat Tourette's Syndrome. Clonidine has also been used to reduce menopausal flushing, to treat postherpetic neuralgia, to treat ulcerative colitis, and to diagnose pheochromocytoma.

Clonidine may also be used for other purposes not listed in this medication guide.

Important information about clonidine

Do not stop taking this medication suddenly without first talking to your doctor. Stopping this medication suddenly can cause nervousness, agitation, headache, tremors, severe high blood pressure, or life-threatening symptoms. Talk with your doctor about how to avoid withdrawal symptoms when you stop taking clonidine. Avoid drinking alcohol. It can increase some of the side effects of clonidine.

Tell your doctor about all the prescription and over-the-counter medications you use. This includes vitamins, minerals, herbal products, and drugs prescribed by other doctors. Do not start using a new medication without telling your doctor.

Clonidine can cause side effects that may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be awake and alert.

Keep using this medicine as directed, even if you feel well. High blood pressure often has no symptoms. You may need to use blood pressure medication for the rest of your life.

Before taking clonidine

If you have certain conditions, you may need a dose adjustment or special tests to safely use clonidine. Before you take clonidine, tell your doctor if you have:

heart disease or severe coronary artery disease;
a heart rhythm disorder;
a history of heart attack or stroke;
kidney disease; or
if you have ever had an allergic reaction to a clonidine transdermal skin patch (Catapres TTS).

FDA pregnancy category C. It is not known if clonidine is harmful to an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant during treatment. Clonidine can pass into breast milk and may harm a nursing baby. Do not take this medication without telling your doctor if you are breast-feeding a baby. Do not give this medication to a child younger than 12 years old.

How should I take clonidine?

Your doctor may occasionally change your dose to make sure you get the best results from clonidine.

Clonidine is usually taken in the morning and at bedtime. Follow your doctor's instructions.

If you need to have any type of surgery, tell the surgeon ahead of time that you are taking clonidine. You may need to stop using the medicine for a short time. Do not stop taking this medication suddenly without first talking to your doctor. Stopping this medication suddenly can cause nervousness, agitation, headache, tremors, severe high blood pressure, or life-threatening symptoms. Talk with your doctor about how to avoid withdrawal symptoms when you stop taking clonidine.

Keep using this medicine as directed, even if you feel well. High blood pressure often has no symptoms. You may need to use blood pressure medication for the rest of your life.
Store clonidine at room temperature away from moisture, heat, and light.

What happens if I miss a dose?

What happens if I overdose?

Overdose symptoms may include high blood pressure (severe headache, blurred vision, buzzing in your ears, anxiety, confusion, chest pain, shortness of breath) followed by low blood pressure (feeling light-headed, fainting), drowsiness, cold feeling, slow heart rate, shallow breathing, weakness, fainting, or pinpoint pupils.

What should I avoid while taking clonidine?

Clonidine side effects

fast or pounding heartbeats;
a very slow heart rate (fewer than 60 beats per minute);
feeling short of breath, even with mild exertion;
swelling, rapid weight gain;
confusion, hallucinations;
fever, pale skin;
urinating less than usual or not at all; or
feeling like you might pass out.

Less serious clonidine side effects may include:

feeling dizzy, drowsy, tired, or nervous;
dry mouth;
dry or burning eyes, blurred vision;
headache, muscle or joint pain;
nausea, vomiting, constipation, loss of appetite;
sleep problems (insomnia);
urinating more at night;
mild skin rash or itching; or
decreased sex drive, impotence.

This is not a complete list of side effects and others may occur. Tell your doctor about any unusual or bothersome side effect.

What other drugs will affect clonidine?

Tell your doctor about all other medications you use, especially:

clonidine transdermal skin patches (Catapres TTS);
digitalis (digoxin, Lanoxin, Lanoxicaps);
an antidepressant such as amitriptyline (Elavil, Etrafon);
a beta-blocker such as atenolol (Tenormin), carvedilol (Coreg), labetalol (Normodyne, Trandate), metoprolol (Lopressor, Toprol), nadolol (Corgard), propranolol (Inderal, InnoPran), sotalol (Betapace), and others;
a calcium channel blocker such as amlodipine (Norvasc), diltiazem (Tiazac, Cartia, Cardizem), felodipine (Plendil), nifedipine (Procardia, Adalat), verapamil (Calan, Covera, Isoptin, Verelan), and others; or
any other drugs to treat high blood pressure or heart problems.

This list is not complete and there may be other drugs that can interact with clonidine. Tell your doctor about all the prescription and over-the-counter medications you use. This includes vitamins, minerals, herbal products, and drugs prescribed by other doctors. Do not start using a new medication without telling your doctor.

Where can I get more information?