Examples

Thiazide diuretics

Loop diuretics

Potassium-sparing diuretics

Quinazoline diuretics

How It Works

Diuretics cause the kidneys to remove more sodium and water from the body, which helps to relax the blood vessel walls, thereby lowering blood pressure.

Diuretics often are combined with other high blood pressure medicines. Some of the brand names listed here are a combination of a diuretic and another medicine. Using both a diuretic and another medicine often works well, because diuretics can enhance the effect of the other medicines and sometimes prevent the fluid retention that can occur.

Potassium-sparing diuretics, unlike most other diuretics, do not cause potassium levels to drop. Rather, they may lead to high potassium levels.

Why It Is Used

Thiazide diuretics are recommended as the first line of treatment for high blood pressure. They are usually recommended as one of at least two medicines to control high blood pressure.

Quinazoline diuretics are similar to the thiazide diuretics, but are used only in certain people such as those with kidney problems and when other diuretics have not worked.

Loop diuretics are prescribed for people who also have heart failure, kidney problems, or swelling in their legs (edema). But they are rarely prescribed for people who have high blood pressure alone.

Potassium-sparing diuretics might be used, along with other diuretics, if you have low potassium levels.¹

How Well It Works

Diuretics lower blood pressure.¹ By lowering blood pressure, they help lower the risk for heart disease, heart attack, and stroke.

Side Effects

All medicines have side effects. But many people don't feel the side effects, or they are able to deal with them. Ask your pharmacist about the side effects of each medicine you take. Side effects are also listed in the information that comes with your medicine.

Here are some important things to think about:

• Usually the benefits of the medicine are more important than any minor side effects.
• Side effects may go away after you take the medicine for a while.
• If side effects still bother you and you wonder if you should keep taking the medicine, call your doctor. He or she may be able to lower your dose or change your medicine. Do not suddenly quit taking your medicine unless your doctor tells you to.

Callor other emergency services right away if you have:

• Trouble breathing.
• Hives.
• Swelling of your face, lips, tongue, or throat.

Call your doctor right away if you have symptoms of changes in potassium levels:

• Confusion
• Dry mouth or increased thirst
• Irregular heartbeat
• Muscle cramps or pain
• Numbness or tingling in your hands, feet, or lips

Other side effects of this medicine include:

• Loss of appetite.
• Stomachaches.
• Nausea.
• Skin sensitive to sunlight.

See Drug Reference for a full list of side effects. (Drug Reference is not available in all systems.)

What To Think About

You may feel more tired or need to urinate more often when you start taking this medicine. These effects typically occur less after you have taken the medicine for a while. If the increase in urine interferes with your sleep or daily activities, ask your doctor to help you plan a schedule for taking the medicine.

Ask your doctor if you need to take a potassium supplement or if you need to watch the amount of potassium in your diet. If you take a loop diuretic or thiazide diuretic, your doctor may suggest you get extra potassium, because these medicines lower your potassium levels. But if you take a potassium-sparing diuretic, you do not need to get extra potassium in your diet.

For tips on taking blood pressure medicine, see:

High Blood Pressure: Taking Medicines Properly.

Taking medicine

Medicine is one of the many tools your doctor has to treat a health problem. Taking medicine as your doctor suggests will improve your health and may prevent future problems. If you don't take your medicines properly, you may be putting your health (and perhaps your life) at risk.

There are many reasons why people have trouble taking their medicine. But in most cases, there is something you can do. For suggestions on how to work around common problems, see the topic Taking Medicines as Prescribed.

Advice for women

If you are pregnant, breast-feeding, or trying to get pregnant, do not use any medicines unless your doctor tells you to. Some medicines can harm your baby. This includes prescription and over-the-counter medicines, vitamins, herbs, and supplements. And make sure that all your doctors know that you are pregnant, breast-feeding, or planning to get pregnant.

Checkups

You will likely have regular doctor visits to check the potassium levels in your blood.

Follow-up care is a key part of your treatment and safety. Be sure to make and go to all appointments, and call your doctor if you are having problems. It's also a good idea to know your test results and keep a list of the medicines you take.

Complete the new medication information form (PDF)(What is a PDF document?) to help you understand this medication.

References

Credits