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What is clonidine

Clonidine lowers blood pressure by decreasing the levels of certain chemicals in your blood. This allows your blood vessels (veins and arteries) to relax (widen) and your heart to beat more slowly and easily.

Clonidine is used to treat hypertension (high blood pressure).

Clonidine may also be used for purposes other than those listed in this medication guide.

General medical information about clonidine

Do not stop taking clonidine suddenly. This could cause severely high blood pressure, nervousness, and anxiety.

Use caution when driving, operating machinery, or performing other hazardous activities. Clonidine may cause dizziness or drowsiness. If you experience dizziness or drowsiness, avoid these activities.

Use caution when rising from a sitting or lying position, especially first thing in the morning. You may become dizzy while taking clonidine and you may fall and injure yourself if you get up quickly.

Do not use alcohol, antihistamines, prescription pain relievers, sleeping pills, and other drugs that may cause drowsiness or dizziness except under the supervision of your doctor.

Who should not take clonidine

Before taking this medication, tell your doctor if you
- have any type of heart disease,
- have had a heart attack or a stroke,
- have liver disease, or
- have kidney disease.

You may need a lower dose or special monitoring during treatment with clonidine if you have any of the conditions listed above.

Clonidine is in the FDA pregnancy category C. This means that it is not known whether clonidine will harm an unborn baby. Do not take this medication without first talking to your doctor if you are pregnant.

Clonidine passes into breast milk. It is not known whether clonidine will harm a nursing infant. Do not take clonidine without first talking to your doctor if you are breast-feeding a baby.

If you are over 60 years of age, you may be more likely to experience side effects from clonidine therapy. You may require a lower dose.

How should take clonidine

Take clonidine exactly as directed by your doctor. If you do not understand these directions, ask your pharmacist, nurse, or doctor to explain them to you.

Take each tablet with a full glass of water.

Take clonidine at bedtime unless otherwise directed by your doctor. Clonidine may make you drowsy and may cause some dizziness. Taking it at bedtime may prevent falls and injuries.

Do not stop taking this medication suddenly even if you feel better. You may need to take clonidine for the rest of your life to control your condition.

Store this medication at room temperature away from moisture and heat.

If you miss a dose:

Take the missed dose as soon as you remember. However, if it is almost time for your next dose, skip the dose you missed and take only your next regularly scheduled dose. Do not take a double dose of this medication.

What happens if you overdose:

Seek emergency medical attention.

Symptoms of a clonidine overdose include drowsiness, lethargy, weakness, lightheadedness, a slow heart rate, nausea, vomiting, and possibly seizures.

Avoid while taking clonidine

Use caution when driving, operating machinery, or performing other hazardous activities. Clonidine may cause dizziness or drowsiness. If you experience dizziness or drowsiness, avoid these activities.

Use caution when rising from a sitting or lying position, especially first thing in the morning. You may become dizzy while taking clonidine and you may fall and injure yourself if you get up quickly.

Avoid alcohol while taking clonidine. It may increase the drowsiness and may also increase dizziness. Use caution even with small amounts of alcohol.

Avoid other drugs such as sleeping pills, antihistamines, prescription pain relievers, and antidepressants unless they are approved by your doctor. These medicines will increase the drowsiness caused by clonidine. Talk to your doctor or pharmacist about any other prescription or over-the-counter medications you are taking.

Possible side effects of clonidine

If you experience any of the following serious side effects, stop taking clonidine and seek emergency medical attention:
- an allergic reaction (difficulty breathing; closing of your throat; swelling of your lips, tongue, or face; or hives);
- a very slow heart rate (fewer than 60 beats per minute); or
- unusually high or low blood pressure (severe headache, redness of the face, neck, and chest, dizziness, and fainting).

Other, less serious side effects may be more likely to occur. Continue to take clonidine and talk to your doctor if you experience any of the following:
- unusual fatigue, dizziness, or tiredness;
- headache;
- constipation, nausea, vomiting, or diarrhea;
- insomnia; or
- a dry mouth (sucking on ice chips or sugarless hard candy may relieve this side effect).

Side effects other than those listed here may also occur. Talk to your doctor about any side effect that seems unusual or that is especially bothersome.

What other drugs will affect clonidine

Clonidine may increase the effects of other drugs that cause drowsiness, including antidepressants, alcohol, antihistamines, sedatives (used to treat insomnia), pain relievers, anxiety medicines, and muscle relaxants. Tell your doctor about all medicines that you are taking, and do not take any medicine unless your doctor approves.

Before taking clonidine, tell your doctor if you are taking any of the following medicines:
- a beta-blocker such as atenolol (Tenormin), acebutolol (Sectral), propranolol (Inderal), metoprolol (Lopressor), carvedilol (Coreg), carteolol (Cartrol), labetalol (Normodyne, Trandate), or nadolol (Corgard);
- levodopa (Dopar, Larodopa, Sinemet);
- prazosin (Minipress); or
- verapamil (Verelan, Calan, Isoptin, Covera-HS); or
- a tricyclic antidepressant such as amitriptyline (Elavil, Endep), imipramine (Tofranil), nortriptyline (Pamelor, doxepin (Sinequan), and others.

You may require special monitoring or a dose adjustment if you are taking any of the medicines listed above.

Drugs other than those listed here may also interact with clonidine or affect your condition. Talk to your doctor and pharmacist before taking any prescription or over-the-counter medicines.

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