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Prazosin and Polythiazide  (Systemic)

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Brand Names

In the U.S.—

  • Minizide

Category


Description

Prazosin and polythiazide (PRA-zoe-sin and pol-i-THYE-a-zide ) combination is used in the treatment of high blood pressure (hypertension).

High blood pressure adds to the workload of the heart and arteries. If it continues for a long time, the heart and arteries may not function properly. This can damage the blood vessels of the brain, heart, and kidneys resulting in a stroke, heart failure, or kidney failure. High blood pressure may also increase the risk of heart attacks. These problems may be less likely to occur if blood pressure is controlled.

Prazosin works by relaxing blood vessels so that blood passes through them more easily. The polythiazide in this combination is a thiazide diuretic (water pill) that helps to reduce the amount of water in the body by increasing the flow of urine. Both of these actions help to lower blood pressure.

This medicine is available only with your doctor's prescription, in the following dosage form:



Before Using This Medicine

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For prazosin and polythiazide, the following should be considered:

Allergies—Tell your doctor if you have ever had any unusual or allergic reaction to prazosin, sulfonamides (sulfa drugs), bumetanide, furosemide, acetazolamide, dichlorphenamide, methazolamide, or any of the thiazide diuretics. Also tell your health care professional if you are allergic to any other substance, such as foods, preservatives, or dyes.

Pregnancy—When polythiazide (contained in this combination medicine) is used during pregnancy, it may cause side effects including jaundice, blood problems, and low potassium in the newborn infant. The combination of prazosin and polythiazide has not been shown to cause birth defects.

Breast-feeding—Polythiazide passes into breast milk. Prazosin passes into breast milk in small amounts. However, prazosin and polythiazide combination has not been reported to cause problems in nursing babies.

Children—Although there is no specific information about the use of this medicine in children, it is not expected to cause different side effects or problems in children than it does in adults. However, extra caution may be necessary in infants with jaundice, because these medicines can make the condition worse.

Older adults—Dizziness, lightheadedness, or fainting or symptoms of too much potassium loss may be more likely to occur in the elderly, who are more sensitive to the effects of prazosin and polythiazide. In addition, this medicine may reduce tolerance to cold temperatures in elderly patients.

Other medicines—Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking prazosin and polythiazide, it is especially important that your health care professional know if you are taking any of the following:

Other medical problems—The presence of other medical problems may affect the use of prazosin and polythiazide. Make sure you tell your doctor if you have any other medical problems, especially:


Proper Use of This Medicine

In addition to the use of the medicine your doctor has prescribed, treatment for your high blood pressure may include weight control and care in the types of foods you eat, especially foods high in sodium. Your doctor will tell you which of these are most important for you. You should check with your doctor before changing your diet.

Many patients who have high blood pressure will not notice any signs of the problem. In fact, many may feel normal. It is very important that you take your medicine exactly as directed and that you keep your appointments with your doctor even if you feel well.

Remember that this medicine will not cure your high blood pressure but it does help control it. Therefore, you must continue to take it as directed if you expect to lower your blood pressure and keep it down. You may have to take high blood pressure medicine for the rest of your life . If high blood pressure is not treated, it can cause serious problems such as heart failure, blood vessel disease, stroke, or kidney disease.

This medicine may cause you to have an unusual feeling of tiredness when you begin to take it. You may also notice an increase in the amount of urine or in your frequency of urination. After taking the medicine for a while, these effects should lessen.

It is best to plan your dose or doses according to a schedule that will least affect your personal activities and sleep. Ask your health care professional to help you plan the best time to take this medicine.

To help you remember to take your medicine, try to get into the habit of taking it at the same time each day.

Dosing—

The dose of prazosin and polythiazide combination will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of prazosin and polythiazide combination. If your dose is different, do not change it unless your doctor tells you to do so.

The number of capsules that you take depends on the strength of the medicine.

Missed dose—

If you miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.

Storage—

To store this medicine:


Precautions While Using This Medicine

It is important that your doctor check your progress at regular visits to make sure this medicine is working properly.

Do not take other medicines unless they have been discussed with your doctor. This especially includes over-the-counter (nonprescription) medicine for appetite control, asthma, colds, cough, hay fever, or sinus problems, since they may tend to increase your blood pressure.

This medicine may cause a loss of potassium from your body.

Check with your doctor if you become sick and have severe or continuing vomiting or diarrhea. These problems may cause you to lose additional water and potassium.

Dizziness, lightheadedness, or sudden fainting may occur after you take this medicine, especially when you get up from a lying or sitting position. These effects are more likely to occur when you take the first dose of this medicine. Taking the first dose at bedtime may prevent problems. However, be especially careful if you need to get up during the night. These effects may also occur with any doses you take after the first dose. Getting up slowly may help lessen this problem. If you feel dizzy, lie down so that you do not faint. Then sit for a few moments before standing to prevent the dizziness from returning.

Make sure you know how you react to this medicine before you drive, use machines, or do anything else that could be dangerous if you are dizzy or are not alert. After you have taken several doses of this medicine, these effects should lessen.

The dizziness, lightheadedness, or fainting is also more likely to occur if you drink alcohol, stand for a long time, exercise, or if the weather is hot. While you are taking this medicine, be careful to limit the amount of alcohol you drink. Also, use extra care during exercise or hot weather or if you must stand for a long time.

For diabetic patients:

Some people who take this medicine may become more sensitive to sunlight than they are normally. Exposure to sunlight, even for brief periods of time, may cause a skin rash, itching, redness or other discoloration of the skin, or a severe sunburn. When you begin taking this medicine:

If you have a severe reaction from the sun, check with your doctor.


Side Effects of This Medicine

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor as soon as possible if any of the following side effects occur, especially since some of them may mean that your body is losing too much potassium:

Other side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. However, check with your doctor if any of the following side effects continue or are bothersome:

Other side effects not listed above may also occur in some patients. If you notice any other effects, check with your doctor.



Revised: 08/20/1998

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