Asa Diuretics: Definition, Indications, Mechanism of Action, Effectiveness, Warnings and Side Effects

You have probably heard the phrase “water retention”, usually in reference to uncomfortable or unattractive swelling.

However, water retention can also have the most serious effect of raising blood pressure.

Sodium in the diet often contributes to this fluid retention, also called edema. Your doctor may prescribe a diuretic medication, which acts to increase urination and eliminate this excess fluid.

Although they are also used to treat other conditions, diuretics are commonly prescribed as a treatment for high blood pressure .

These medications, also known as water pills, can cause a number of side effects, including muscle cramps . If you have cramps and take a diuretic, consult your doctor for further evaluation.

Diuretics work by helping your body excrete excess fluids and sodium. Removing excess fluid from the body is important because it can cause too much pressure on the walls of the blood vessels.

This puts him at risk for hypertension , which can have important cardiovascular repercussions. Polycystic ovarian syndrome, heart failure, kidney problems and osteoporosis are some other conditions that can be treated with diuretics.

You may experience frequent urination when you take a diuretic, especially in the first few weeks.


Your doctor can put it in a potassium supplement or recommend increasing your dietary intake if laboratory tests confirm that your levels are low. Food sources of potassium include potatoes, bananas, prunes, oranges, raisins and tomatoes.

You may also be prescribed a different type of water pill. Known as potassium-sparing diuretics, these medications do not cause low levels of this mineral.

What are the names of diuretic medications for high blood pressure?

Thiazide diuretics (water tablets) are used as first-line treatment to reduce high blood pressure or are combined with other kinds of blood pressure treatment if the single medication alone does not control blood pressure.

Thiazide diuretics include bendroflumetiazide, chlorthalidone, cyclopentiazide, indapamide, xipamide, and metolazone.

Mechanism of action of the loop Diuretics

Thiazide diuretics work in two main ways:

The main action of thiazide diuretics is to increase the loss of fluids and salts from the body through the kidneys. That is why they are popularly known as “water tablets”. This action reduces blood pressure by reducing the volume of fluid in the circulation.

Thiazide diuretics also cause mild dilation of the small arteries (arterioles) in the circulation.

This dilation decreases blood pressure by reducing the resistance caused as blood is pumped from a larger diameter artery to those with a smaller diameter, and provides more “space” for the fluid to expand within the circulation.

The thiazides act in 1 or 2 hours after taking a tablet, and its action lasts between 12 and 24 hours.

How effective are thiazide diuretics?

Relatively low doses of thiazide diuretics are used to lower blood pressure (higher doses are used to relieve the inflammation associated with chronic heart failure ).

On average, thiazide diuretics reduce your systolic blood pressure when used alone. Higher doses tend not to have a greater blood pressure lowering effect and are more likely to cause side effects.

Many popular dual therapies combine a thiazide-like diuretic with an angiotensin-converting enzyme inhibitor, a calcium channel blocker, or an angiotensin receptor blocker.

Different diuretics can be taken together, and you can take them with other medications, sometimes in the same pill.

  • Chlorthalidone (Hygroton).
  • Chlorothiazide (Diuril).
  • Hidroclorotiazida o HCTZ (Esidrix, Hydrodiuril, Microzide).
  • Indapamida (Lozol).
  • Metolazona (Mykrox, Zaroxolina).
  • Amilorida (Midamor).
  • Bumetanida (Bumex).
  • Furosemide (Lasix).
  • Espironolactone (Aldactona).
  • Triamterene (Dyrenium).

What should you consider when taking diuretics for high blood pressure?

Tell your doctor what medications (with and without a prescription), supplements and herbal remedies you use. You should also tell him about other medical problems you have.

You may want to regularly monitor your blood pressure, as well as analyze your blood and urinate to know the specific mineral levels and see how well your kidneys are working.

You will probably be told to follow a low sodium diet and limit the amount of salt you eat.

Because some diuretics also extract potassium from your body, you may need to eat more foods such as bananas, sweet potatoes, spinach, and lentils, or take a potassium supplement.

On the other hand, if you are taking a “potassium-sparing” diuretic, such as amiloride (Midamar), spironolactone (Aldactone) or triamterene (Dyrenium), you may want to avoid potassium-rich foods, salt substitutes, low milk in sodium and other sources of potassium.

If you only need one dose a day, you may want to take your diuretic in the morning so you can sleep through the night instead of getting up to go to the bathroom.

Avoid alcohol and medications to help you sleep. They can make side effects worse.

Muscle cramps also occur, particularly when a diuretic causes loss of potassium. It can cause dizziness or blurred vision with the use of diuretics.


There are dozens of different antihypertensive medications and each has pros and cons. If you have just started taking blood pressure medications, remember that lifestyle factors, such as smoking and salty foods, can keep your medication from working effectively.

If you have high blood pressure, you can reduce your need for medications if you follow a healthy diet, maintain a healthy weight and exercise regularly. Take your medications as prescribed and be sure to monitor your blood pressure at the same time every day.

What are the side effects of diuretics for high blood pressure?

The water that comes out of your body has to go somewhere, so you can expect to urinate more and more often for several hours after a dose.

You also run the risk of becoming dehydrated, and simply drinking more fluids may not be enough. Call your doctor if you are very thirsty or have a very dry mouth, your urine is dark yellow, you do not urinate too much or you have constipation or you have a headache.

You may feel dizzy or dizzy, especially when you stand up, if your blood pressure has dropped too low or if you are dehydrating.

Your blood chemistry can be eliminated. You may have too little or too much sodium or potassium in your system. This can make you tired or weaken or cause muscle cramps or headaches.

It is rare, but your heart may accelerate (more than 100 beats per minute) or you may start vomiting due to a dangerously low potassium level.

Diuretics can make it hard for you to control your blood sugar level, which can lead to diabetes if you do not have it yet. It is more likely to have gout.

Taking combination pills or multiple medications may increase these side effects. To help decrease these chances, ask your doctor when you should take each medication during the day.

Muscle cramps:

Although they are often well tolerated, diuretics can cause a series of side effects, such as dizziness, headaches, thirst and high blood sugar levels. Muscle cramps are also a significant side effect that should not be ignored.

When your body excretes excess fluid and sodium, you are also losing potassium in the process. A mineral with a vital purpose for the whole body, potassium is used for proper muscle function.

If your potassium level is poor, you may experience not only cramps but also muscle weakness and fatigue.

Effects of low potassium content:

Having a low potassium level can have serious health consequences. You may experience constipation , swelling and pain in the abdominal area since the intestines are affected by the deficiency.

Very low potassium levels can be life-threatening and cause heart arrhythmias and muscle paralysis. There is some evidence linking low potassium pressure to high blood pressure, although more research is needed in this area.

Follow your doctor’s recommendations should resolve muscle cramps and other symptoms related to potassium caused by the use of diuretics.

Increased urination and excessive fluid loss:

One of the most common side effects of all diuretics is increased urination. It is particularly common in people who take loop diuretics, as these are the most potent water pills.

The increase in urination can be resolved over time, especially in people who take the other two types of diuretics. When urination is excessive, dehydration may occur.

This can cause low blood pressure with dizziness or lightheadedness, especially when standing. When prolonged, dehydration can damage the kidneys.

Other blood test results:

Both thiazide and loop diuretics can increase blood sugar levels, which can lead to the onset of diabetes.

Thiazide diuretics can increase blood calcium levels and lower magnesium levels, while loop diuretics tend to lower calcium and magnesium levels in the blood.

Both thiazide and loop diuretics can increase blood levels of uric acid.

Over time, this can cause gout, a painful form of arthritis that usually develops in the joints of the toes. Thiazide and loop diuretics can also increase cholesterol and triglyceride levels in the blood.

Other side effects:

Men who take potassium-sparing diuretics may experience impotence or decreased sex drive, since these medications have anti-androgenic effects. Some men also develop breast augmentation.

Premenopausal women who take these diuretics may experience menstrual irregularities, and postmenopausal women may develop uterine bleeding.

All diuretics can cause abdominal discomfort, nausea, vomiting or diarrhea in some people. Inflammatory pancreatic inflammation, called pancreatitis , is a possible but rare side effect of thiazide and loop diuretics.

Occasionally, thiazide diuretics can cause blurred vision and loop diuretics can cause ringing in the ears or decreased hearing. All diuretics can interact with a large number of other medications.

Who should not take diuretics for high blood pressure?

Some diuretics are sulfonamides, so they could cause a reaction if you are allergic.

Older people tend to have more side effects, such as fainting and dizziness from dehydration. You will have to work closely with your doctor.

Diuretics are not recommended for women who are pregnant or breastfeeding. We do not know how these medications affect the unborn baby and many pass into breast milk, which can dehydrate babies.

Children can take them safely, but they need smaller doses. Side effects are similar to those of adults, but potassium-sparing diuretics can cause low levels of calcium, which could damage bone development.