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Methyldopa and Thiazide Diuretics  (Systemic)

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Brand Names

Some commonly used brand names are:

In the U.S.—

  • Aldoclor1
  • Aldoril2

In Canada—

  • Novodoparil2
  • PMS Dopazide2
  • Supres1

Note:

For quick reference, the following medicines are numbered to match the corresponding brand names.
This information applies to the following medicines:
1.  Methyldopa and Chlorothiazide (meth-il-DOE-pa and klor-oh-THYE-a-zide)
2.  Methyldopa and Hydrochlorothiazide (meth-il-DOE-pa and hye-droe-klor-oh-THYE-a-zide)
‡  Generic name product may be available in the U.S.
§  Generic name product may be available in Canada
*  Not commercially available in the U.S.
†  Not commercially available in Canada

Category


Description

Combinations of methyldopa and a thiazide diuretic (chlorothiazide or hydrochlorothiazide) are used to treat 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.

Methyldopa works by controlling nerve impulses along certain nerve pathways. As a result, it relaxes blood vessels so that blood passes through them more easily. Thiazide diuretics help reduce the amount of water in the body by increasing the flow of urine. These actions help to lower blood pressure.

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



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 methyldopa and thiazide diuretics, the following should be considered:

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

Pregnancy—Studies in humans have not shown that methyldopa causes birth defects or other problems. However, when thiazide diuretics are used during pregnancy, they may cause side effects including jaundice, blood problems, and low potassium in the newborn infant. Thiazide diuretics have not been shown to cause birth defects.

Breast-feeding—This medicine passes into breast milk. Thiazide diuretics may decrease the flow of breast milk. Therefore, you should avoid use of thiazide diuretics during the first month of breast-feeding.

Children—Although there is no specific information comparing use of this medicine in children with use in other age groups, it is not expected to cause different side effects or problems in children than it does in adults.

Older adults—Dizziness or light-headedness, drowsiness, or signs of too much potassium loss may be more likely to occur in the elderly, who are more sensitive to the effects of methyldopa and thiazide diuretics.

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 methyldopa and thiazide diuretics, 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 methyldopa and thiazide diuretics. 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, appropriate 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 factors 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. In general, to keep the increase in urine from affecting your sleep:

However, 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 methyldopa and thiazide diuretic combinations 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 methyldopa and thiazide diuretic combinations. If your dose is different, do not change it unless your doctor tells you to do so:

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 that 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) medicines 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.

Before having any kind of surgery (including dental surgery) or emergency treatment, tell the medical doctor or dentist in charge that you are taking this medicine.

If you have a fever and there seems to be no reason for it, check with your doctor. This is especially important during the first few weeks you take this medicine since fever may be a sign of a serious reaction to methyldopa.

This medicine may cause some people to become drowsy or less alert than they are normally. This is more likely to happen when you begin to take it or when you increase the amount of medicine you are taking. 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 not alert.

Dizziness, light-headedness, or fainting may occur, especially when you get up from a lying or sitting position. Getting up slowly may help, but if the problem continues or gets worse, check with your doctor.

The dizziness, light-headedness, or fainting is also more likely to occur if you drink alcohol, stand for long periods of time, exercise, or if the weather is hot. Drinking alcoholic beverages may also make the drowsiness worse. While you are taking this medicine, be careful in the amount of alcohol you drink. Also, use extra care during exercise or hot weather or if you must stand for long periods of time.

For diabetic patients:

This medicine may cause dryness of the mouth. For temporary relief, use sugarless candy or gum, melt bits of ice in your mouth, or use a saliva substitute. However, if your mouth continues to feel dry for more than 2 weeks, check with your medical doctor or dentist. Continuing dryness of the mouth may increase the chance of dental disease, including tooth decay, gum disease, and fungus infections.

Thiazide diuretics may cause your skin to be more sensitive to sunlight than it is 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.

Before you have any medical tests, tell the doctor in charge that you are taking this medicine. The results of some tests may be affected by this medicine.


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 immediately if the following side effect occurs:

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: 08/28/2000

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