Medically reviewed by  A Ras MD.

What is Clorpres?

Clorpres is a prescription medicine that is used to treat high blood pressure.

Description

CLORPRES (clonidine hydrochloride and chlorthalidone) ® is a combination of clonidine hydrochloride (a centrally acting antihypertensive agent) and chlorthalidone (a diuretic).

CLORPRES (clonidine hydrochloride and chlorthalidone) ® is available as tablets for oral administration in three dosage strengths: 0.1 mg/15 mg, 0.2 mg/15 mg and 0.3 mg/15 mg of clonidine hydrochloride/chlorthalidone, respectively.

The inactive ingredients are ammonium chloride, colloidal silicon dioxide, croscarmellose sodium (Type A), magnesium stearate, microcrystalline cellulose, sodium lauryl sulfate, D&C yellow #10.

Clonidine Hydrochloride

Clonidine hydrochloride is an imidazoline derivative and exists as a mesomeric compound. The chemical name is 2-[(2,6-dichlorophenyl)imino]imidazoline monohydrochloride. The following are the structural formula, molecular formula and molecular weight:

Clonidine hydrochloride is an odorless, bitter, white crystalline substance soluble in water and alcohol.

Chlorthalidon

Chlorthalidone is a monosulfamyl diuretic that differs chemically from thiazide diuretics in that a double ring system is incorporated in its structure. It is 2-chloro-5-(1-hydroxy-3-oxo-1-isoindolinyl) benzenesulfonamide with the following structural formula, molecular formula and molecular weight:

Chlorthalidone is practically insoluble in water, in ether and in chloroform; soluble in methanol; slightly soluble in alcohol.

Before taking Clorpres, tell your doctor:

• If you are allergic to this medicine (Clorpres); any part of this medicine (Clorpres); or any other drugs, foods, or substances. Tell your doctor about the allergy and what signs you had.
• If you are not able to pass urine.
• If you are breast-feeding or plan to breast-feed.

This is not a list of all drugs or health problems that interact with this medicine (Clorpres).

Tell your doctor and pharmacist about all of your drugs (prescription or OTC, natural products, vitamins) and health problems. You must check to make sure that it is safe for you to take this medicine (Clorpres) with all of your drugs and health problems. Do not start, stop, or change the dose of any drug without checking with your doctor.

What are some things I need to know or do while I take Clorpres?

• Tell all of your health care providers that you take this medicine (Clorpres). This includes your doctors, nurses, pharmacists, and dentists.
• Avoid driving and doing other tasks or actions that call for you to be alert until you see how this medicine (Clorpres) affects you.
• To lower the chance of feeling dizzy or passing out, rise slowly if you have been sitting or lying down. Be careful going up and down stairs.
• If you have asthma, talk with your doctor. You may be more sensitive to this medicine (Clorpres).
• If you have high blood sugar (diabetes), you will need to watch your blood sugar closely.
• If you are on a low-salt or salt-free diet, talk with your doctor.
• Check blood pressure and heart rate as the doctor has told you.
• Have blood work checked as you have been told by the doctor. Talk with the doctor.
• This medicine may affect certain lab tests. Tell all of your health care providers and lab workers that you take this medicine (Clorpres).
• Talk with your doctor before using OTC products that may raise blood pressure. These include cough or cold drugs, diet pills, stimulants, ibuprofen or like products, and some natural products or aids.
• This medicine is a strong fluid-lowering drug (diuretic). Sometimes too much water and electrolytes (like potassium) in the blood may be lost. This can lead to severe health problems. Your doctor will follow you closely to change the dose to match your body’s needs.
• You may need extra potassium. Talk with your doctor.
• Talk with your doctor before you drink alcohol or use other drugs and natural products that slow your actions.
• Be careful in hot weather or while being active. Drink lots of fluids to stop fluid loss.
• Tell your doctor if you have too much sweat, fluid loss, throwing up, or loose stools. This may lead to low blood pressure.
• Watch for gout attacks.
• If you have lupus, this medicine (Clorpres) can make your lupus active or get worse. Tell your doctor right away if you get any new or worse signs.
• This medicine may make you sunburn more easily. Use care if you will be in the sun. Tell your doctor if you sunburn easily while taking this medicine (Clorpres).
• Tell your doctor if you are pregnant or plan on getting pregnant. You will need to talk about the benefits and risks of using this medicine (Clorpres) while you are pregnant.

How is Clorpres best taken?

Use this medicine (Clorpres) as ordered by your doctor. Read all information given to you. Follow all instructions closely.

• Keep taking this medicine (Clorpres) as you have been told by your doctor or other health care provider, even if you feel well.
• Take with or without food.
• This medicine may cause you to pass urine more often. To keep from having sleep problems, try not to take too close to bedtime.
• Do not stop taking this medicine (Clorpres) all of a sudden without calling your doctor. You may have a greater risk of side effects. If you need to stop this medicine (Clorpres), you will want to slowly stop it as ordered by your doctor.

What do I do if I miss a dose?

• Take a missed dose as soon as you think about it.
• If it is close to the time for your next dose, skip the missed dose and go back to your normal time.
• Do not take 2 doses at the same time or extra doses.

What are the side effects of Clorpres that I need to call my doctor about immediately?

WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:

• Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.
• Signs of high blood sugar like confusion, feeling sleepy, more thirst, more hungry, passing urine more often, flushing, fast breathing, or breath that smells like fruit.
• Signs of fluid and electrolyte problems like mood changes, confusion, muscle pain or weakness, a heartbeat that does not feel normal, very bad dizziness or passing out, fast heartbeat, more thirst, seizures, feeling very tired or weak, not hungry, unable to pass urine or change in the amount of urine produced, dry mouth, dry eyes, or very bad upset stomach or throwing up.
• Signs of kidney problems like unable to pass urine, change in how much urine is passed, blood in the urine, or a big weight gain.
• Signs of a pancreas problem (pancreatitis) like very bad stomach pain, very bad back pain, or very bad upset stomach or throwing up.
• Very bad dizziness or passing out.
• Change in eyesight.
• Yellow skin or eyes.
• A burning, numbness, or tingling feeling that is not normal.
• Fever or chills.
• Very bad sore throat.
• Any unexplained bruising or bleeding.
• Feeling very tired or weak.
• Restlessness.

What are some other side effects of Clorpres?

All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:

• Constipation.
• Dizziness.
• Feeling sleepy.
• Dry mouth.
• Upset stomach or throwing up.
• Not hungry.
• Stomach cramps.
• Diarrhea.
• Feeling tired or weak.
• Headache.

These are not all of the side effects that may occur. If you have questions about side effects, call your doctor. Call your doctor for medical advice about side effects.

You may report side effects to the FDA at 1-800-332-1088. You may also report side effects at https://www.fda.gov/medwatch.

If overdose is suspected:

If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.

How do I store and/or throw out Clorpres?

• Store at room temperature.
• Protect from light.
• Store in a dry place. Do not store in a bathroom.
• Keep all drugs in a safe place. Keep all drugs out of the reach of children and pets.
• Throw away unused or expired drugs. Do not flush down a toilet or pour down a drain unless you are told to do so. Check with your pharmacist if you have questions about the best way to throw out drugs. There may be drug take-back programs in your area.

SRC: NLM .