Diuretics are medications that promote the production of urine. They help the kidneys flush excess water and salt from the body and lower blood pressure.
Diuretics are also referred to as "water pills".
Clinical Uses of Diuretics
Diuretics may be prescribed for the treatment of a variety of medical conditions, including:
- Hypertension (high blood pressure). Diuretics may be a first-line treatment prescribed for mild cases of hypertension.
- Heart failure. The kidneys have difficulty excreting fluid in those with heart failure. This can lead to a build up of fluid that results in trouble breathing (pulmonary edema) and/or swelling in the legs and ankles (peripheral edema). Diuretics help to maintain proper fluid balance in those with heart failure. For those with heart failure, diuretics are often prescribed with an angiotensin-converting enzyme (ACE) inhibitor or other heart medication.
- Liver cirrhosis.
- Kidney disease. Poorly functioning kidneys may to expel fluids as necessary. Diuretics helps ailing kidneys to do their job of excreting fluid.
Types of Diuretics
There are four commonly prescribed types of diuretics. All diuretics increase the excretion of water from bodies, although each class does so in a distinct way.
- Chlorothiazide (Diuril®)
- Hydrochlorothiazide (Hydrodiuril®, Microzide®)
Thiazide diuretics may be used for mild to moderate heart failure.
- Bumetanide (Bumex®)
- Furosemide (Lasix®)
- Torsemide (Demdex®)
Loop diuretics are most often used for more severe heart failure.
- Amiloride (Midamor®)
- Spironolactone (Aldactone®)
Other diuretics can lead to the loss of potassium in the urine, and result in low blood levels of potassium. These "potassium-sparing" diuretics do not result in the loss of as much potassium.
Besides being potassium-sparing, spironolactone is also an aldosterone receptor antagonist. It blocks the action of aldosterone, a hormone that can make heart failure worse. Spironolactone may prescribed for people taking other medications for heart failure.
Potassium-sparing diuretics may be prescribed for use with other types of diuretics.
Carbonic Anhydrase Inhibitors
- acetazolamide (Diamox®)
These less commonly prescribed diuretics may be recommended in specific circumstances, such as for the prevention of pulmonary or cerebral edema association with altitude sickness.
The medication dosage may be adjusted over time to identify the amount necessary to reduce fluid buildup and avoid side effects. You doctor or health care provider may start with a low dose and then increase it as needed.
It may take some time to find the right dose and the best time of day to take a diuretic.
Your doctor may recommend that you to weigh yourself each day as a way of checking your fluid loss and decide whether to adjust the dose of your medication.
Call your doctor if you notice a sudden weight gain. This can be a sign of worsening heart or kidney failure. Your doctor can tell you how much weight gain is safe and when to call. In general, call if you gain 3 pounds or more in 2 to 3 days.
Eating too much salt can reverse the benefits of diuretics. Diuretic therapy should be used along with a low-salt diet.
Side Effects of Diuretics
The main side effects from using a diuretic are as follows:
- hypovolemia (low blood volume). This can lead to symptoms of dehydration, such as thirst and dry mouth
- changes in potassium levels. Depending on the diurectic, a person may be at risk for low potassium levels (hypokalemia) or high potassium levels (hyperkalemia)
- hyperuricemia. This can lead to the onset of gout.
Call your doctor right away if you have the following symptoms:
- Dry mouth or increased thirst
- Irregular heartbeat
- Muscle cramps or pain
- Numbness or tingling in your hands, feet,
- or lips
Call your doctor if you think you are having a problem with your medicine. Call 911 right
away if you think you are having a serious reaction, such as trouble breathing.
Issues to Keep in Mind
You may feel more tired or need to urinate more often when you start taking a diuretic. These effects typically lessen after you have taken the medicine for a while. If the increase in urine interferes with your sleep or daily activities, ask your doctor about changing the timing or dosage of the medication.
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 medication lower your potassium levels. If you take a potassium-sparing diuretic, such as furosemide, you probably do not need take extra potassium unless instructed.
Read the Medication Guide you receive with your prescription for a complete list of usage instructions and side effects.
Reference: National Heart, Lung & Blood Institute (NHLBI)