Clonidine and chlorthalidone

Generic name: clonidine and chlorthalidone [ KLOE-ni-deen-and-klor-THAL-i-done ]
Brand names: Clorpres, Combipres
Drug class: Antiadrenergic agents (central) with thiazides

Medically reviewed: December 15, 2017

What is clonidine and chlorthalidone?

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

Chlorthalidone is a thiazide diuretic (water pill) that helps prevent your body from absorbing too much salt, which can cause fluid retention.

The combination of clonidine and chlorthalidone treats fluid retention (edema) in people with congestive heart failure, cirrhosis of the liver, or kidney disorders, or edema caused by taking steroids or estrogen. This medication is also used to treat high blood pressure (hypertension).

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

Important Information

Do not use this medication if you are unable to urinate.

Before using this medication, tell your doctor if you are allergic to sulfa drugs, or if you have liver disease, kidney disease, asthma, allergies, gout, lupus, or diabetes.

Avoid drinking alcohol, which can increase some of the side effects of clonidine and chlorthalidone.

Do not stop using this medication suddenly without first talking to your doctor. Stopping this medication suddenly can cause nervousness, anxiety, severe high blood pressure, or life-threatening symptoms. You will need to use less and less before you stop the medication completely.

Avoid becoming overheated or dehydrated during exercise and in hot weather. Follow your doctor's instructions about the type and amount of liquids you should drink. In some cases, drinking too much liquid can be as unsafe as not drinking enough.

Tell your doctor if you regularly use other medicines that make you sleepy (such as cold or allergy medicine, narcotic pain medicine, sleeping pills, muscle relaxers, and medicine for seizures, depression, or anxiety). They can add to the side effects of clonidine and chlorthalidone.

This medication 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 clonidine and chlorthalidone as directed, even if you feel well. High blood pressure often has no symptoms, so you may not know when your blood pressure is high. You may need to use blood pressure medication for the rest of your life.

Related/similar drugs

amlodipine, lisinopril, metoprolol, losartan, furosemide, hydrochlorothiazide

What should I discuss with my doctor before taking clonidine and chlorthalidone?

Do not use this medication if you are allergic to clonidine or chlorthalidone, or if you are unable to urinate.

Before using clonidine and chlorthalidone, tell your doctor if you are allergic to any drugs, or if you have:

• kidney disease;

• liver disease;

• asthma or allergies;

• gout;

• lupus;

• diabetes; or

• if you have an allergy to sulfa drugs.

If you have any of these conditions, you may need a dose adjustment or special tests to safely take clonidine and chlorthalidone.

FDA pregnancy category C. This medication may be harmful to an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant during treatment.

Clonidine and chlorthalidone can pass into breast milk and may harm a nursing baby. Do not use this medication without telling your doctor if you are breast-feeding a baby.

How should I take clonidine and chlorthalidone?

Take this medication exactly as it was prescribed for you. Do not take the medication in larger amounts, or take it for longer than recommended by your doctor. Follow the directions on your prescription label.

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

Call your doctor if you have ongoing vomiting or diarrhea, or if you are sweating more than usual. You can easily become dehydrated while taking this medication, which can lead to severely low blood pressure or a serious electrolyte imbalance.

To be sure this medication is helping your condition, your blood pressure will need to be checked often. Do not miss any scheduled appointments.

Your blood and urine may both be tested if you have been vomiting or are dehydrated.

Chlorthalidone can interfere with the results of a thyroid test. Tell any doctor who treats you that you are using this medication.

Keep using clonidine and chlorthalidone as directed, even if you feel well. High blood pressure often has no symptoms, so you may not know when your blood pressure is high. You may need to use blood pressure medication for the rest of your life.

Stopping this medication suddenly can cause nervousness, anxiety, severe high blood pressure, or life-threatening symptoms. You will need to use less and less before you stop the medication completely. Talk with your doctor before you stop taking clonidine and chlorthalidone.

Store the tablets at room temperature away from heat, light, and moisture.

What happens if I miss a dose?

Take the missed dose as soon as you remember. If it is almost time for your next dose, skip the missed dose and take the medicine at the next regularly scheduled time. Do not take extra medicine to make up the missed dose.

What happens if I overdose?

Seek emergency medical attention if you think you have used too much of this medicine. Overdose symptoms may include nausea, vomiting, weakness, drowsiness, limp feeling, pinpoint pupils, slow heart rate, shallow breathing, fainting, or seizure (convulsions).

What should I avoid while taking clonidine and chlorthalidone?

This medication 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.

Tell your doctor if you regularly use other medicines that make you sleepy (such as cold or allergy medicine, narcotic pain medicine, sleeping pills, muscle relaxers, and medicine for seizures, depression, or anxiety). They can add to the side effects of clonidine and chlorthalidone.

Avoid drinking alcohol, which can increase some of the side effects of clonidine and chlorthalidone.

Avoid becoming overheated or dehydrated during exercise and in hot weather. Follow your doctor's instructions about the type and amount of liquids you should drink. In some cases, drinking too much liquid can be as unsafe as not drinking enough.

Avoid exposure to sunlight or artificial UV rays (sunlamps or tanning beds). Clonidine and chlorthalidone can make your skin more sensitive to sunlight and sunburn may result. Use a sunscreen (minimum SPF 15) and wear protective clothing if you must be out in the sun.

Clonidine and chlorthalidone side effects

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have a serious side effect such as:

• dry mouth, increased thirst, drowsiness, restless feeling, nausea, vomiting, increased urination, muscle pain or weakness, fast heart rate, feeling light-headed, fainting, or seizure (convulsions);

• easy bruising or bleeding, unusual weakness;

• red or purple spots on your skin;

• confusion, hallucinations;

• urinating more or less than usual, or not at all;

• feeling short of breath, even with mild exertion;

• swelling, rapid weight gain;

• numbness or tingly feeling; or

• nausea, stomach pain, low fever, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes).

Less serious side effects may include:

• dry mouth, loss of appetite;

• diarrhea, constipation, upset stomach;

• dizziness, drowsiness;

• headache;

• feeling restless or nervous;

• sleep problems (insomnia);

• nightmares or unusual dreams;

• breast swelling or tenderness;

• mild itching or skin rash; or

• impotence or loss of interest in sex.

This is not a complete list of side effects and others may occur. Tell your doctor about any unusual or bothersome side effect. You may report side effects to FDA at 1-800-FDA-1088.

Clonidine and chlorthalidone dosing information

Usual Adult Dose for Hypertension:

Chlorthalidone 15 mg-Clonidine 0.1 to 0.3 mg orally once or twice a day

Maximum dose: Chlorthalidone 30 mg-Clonidine 0.6 mg orally per day

Use: Treatment of hypertension when the desired effect has not been achieved with monotherapy or as substitution for the titrated individual components.

What other drugs will affect clonidine and chlorthalidone?

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

• other blood pressure medications;

• lithium;

• digitalis (digoxin, Lanoxin);

• insulin or diabetes medicine taken by mouth; or

• an antidepressant such as amitriptyline (Elavil, Etrafon), amoxapine (Ascendin), clomipramine (Anafranil), desipramine (Norpramin), imipramine (Janimine, Tofranil), nortriptyline (Pamelor), protriptyline (Vivactil), or trimipramine (Surmontil).

This list is not complete and there may be other drugs that can interact with clonidine and chlorthalidone. 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.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Medical Disclaimer

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