Diuretic Medications: What are they? Indications, Types, Side Effects, Interactions and Contraindications

Although you may not think much about it, there are many fluids in your body in a careful balance.

When you accumulate many fluids, you tend to urinate. That is the role of diuretics.

The human body is a delicate system; it is necessary to discard it to accumulate liquid.

What are diuretics?

Diuretics, also known as water pills, refer to any medication or substance that increases the production of urine and the frequency of urination.

The excess water and salt are absorbed and then excreted by the kidneys when you take a diuretic. Therefore, diuretics change the homeostatic balance in the body by decreasing the total amount of fluids.

What is a diuretic? It is not easy to answer because diuretics include a diverse group of compounds.

The examples of diuretics are varied, and they all regulate the production of urine in different ways. As a result, it is not easy to draw simple conclusions about its use.


Since diuretics change the balance of fluids in the body, it is essential to consult your doctor about the possible effects of taking anything.


Diuretics are prescribed more frequently for the treatment of hypertension. Therefore, the prescribed diuretic reduces blood pressure and the threat of severe diseases through dilation or widening blood vessels.

The combination of diuretics and lower sodium intake tends to work in most cases of hypertension.

Another important therapeutic use for a prescribed diuretic is to treat the symptoms of heart failure. As the heart begins to weaken gradually during heart failure, it fights to eliminate excess fluid from the body.

As a result, the body tissue absorbs the fluid, which causes swelling (edema), weight gain, and difficulty breathing; Diuretics help the body eliminate this excess fluid and relieve congestion in the lungs.

However, diuretics are not only used to relieve symptoms. Almost always combined with other medications related to the heart to slow the progression of heart disease.

Less commonly, diuretics can treat certain types of liver and kidney disease. They can also help treat cases of overdose or poisoning by excreting the harmful substance through the urine.

Heart disease and kidney disease affect millions of lives, and as people live longer, these diseases will become more familiar with each passing year. Therefore, diuretics will be even more critical in the coming years.

A prescription diuretic is one of the most common medications recommended for high blood pressure and heart failure.


Diuretics can be classified into three standard groups: thiazideloop action, and potassium-sparing diuretics.

There are also less common types, including calcium-sparing diuretics, osmotic diuretics, and carbonic anhydrase inhibitors. Each of these exerts a different effect on the human body, so there is no better individual diuretic.

Thiazide diuretics are the most common type. They are prescribed overwhelmingly to treat hypertension because of their ability to relax the muscles of the walls of the vessels, which increases blood flow.

The joint national committee for the prevention, detection, evaluation, and treatment of high blood pressure recommends thiazide diuretics as the first treatment for high blood pressure.

Loop-action diuretics increase the flow of urine in the kidneys, which reduces the amount of water in the body. They are more effective in people with damaged kidney functions.

Potassium-sparing diuretics promote the secretion of urine without losing potassium. This is used when other diuretics can cause an abnormal mineral loss.

Because all diuretics have different effects, the best diuretic depends on what is appropriate for your particular health condition.

What are the common side effects of diuretics?

Since diuretics induce urine secretion, a common side effect is the loss of critical body minerals, such as sodium, calcium, and potassium.

Common minerals in the blood are a severe medical problem, but not all mineral deficiencies are the same. Each one leads to a wide range of different symptoms, so talking with your doctor about possible issues is essential.

A common side effect is the loss of minerals. However, some diuretics can lead to the exact opposite problem: excessive minerals in the blood.

For example, potassium-sparing diuretics are meant to treat low potassium levels in the blood. Still, if they are not carefully controlled, they can cause too much potassium retention unless taken with some medication that counteracts the potassium. Effect.

Another essential side effect of fluid loss is dehydration. This is usually not a problem at low doses, but if you are taking a hefty dose of diuretics, you may accidentally lose too much water through your urine.

People with diuretics should always stay adequately hydrated, especially during intense physical activity or hot summer days.

Because the side effects of diuretics are so broad, it is not easy to generalize all types of diuretics. However, if you have any unusual symptoms, which include:

  • Headaches.
  • Dizziness.
  • Muscle cramps.
  • He retched.
  • Diarrhea.
  • Irritability.

Call your doctor immediately. Do not stop taking your diuretic medications without the explicit instruction of your doctor, as it can make the problem worse.

The use of diuretics can alter the balance of your body; therefore, always follow the explicit instructions of your doctor and try to avoid taking an over-the-counter diuretic for severe conditions.

Is there a natural diuretic?

Diuretics exist in nature and, in theory, have the same qualities and effects as a “synthetic” diuretic. Natural diuretics include:

  • Dandelion.
  • Ginger.
  • Caffeine.

There are two problems when taking an herbal diuretic or any other over-the-counter diuretic. First, an over-the-counter diuretic may not effectively treat an underlying medical condition, such as kidney or heart disease.

Second, according to Katherine Zeratsky, an authorized nutritionist, “some herbs and supplements can worsen your medical problems or interact with your medications.”

In 2014, Claudia Hammond, a BBC journalist, reviewed the scientific literature for evidence of the diuretic effect of caffeine. Evidence suggests that caffeine and diuretic drinks do not have a very pronounced diuretic effect since the frequency of urination remained almost the same.

Because diuretics alter the balance of fluids in your body, it is not a good idea to take supplements without knowing the possible effects. You may simply be risking dehydration.

If you expect to lose weight with water, you should focus on eating a healthier diet and increasing your physical activity.

Taking a natural diuretic can help treat mild fluid retention, but you should talk to your doctor before buying any herbal or natural diuretic instead of diuretics.

Interactions with other drugs or medications

Diuretics interact negatively with other drugs but again depend on the type and dose of the diuretic. You should avoid taking digitalis and digoxin, lithium, antidepressants, and cyclosporin.

You should also avoid taking certain mineral supplements. For example, you will want to avoid taking additional potassium supplements if you take potassium-based diuretics, as these can raise blood potassium levels too high.

Sometimes doctors prescribe other medicines with diuretics.

Is it possible to develop a resistance to diuretics?

In a minority of patients, resistance to diuretics seems to develop as the kidneys adapt to the use of chronic diuretics. It seems to be more common in patients with congestive heart failure. The congestion persists despite the continued use of diuretics.

There is little information available about resistance. However, an effective treatment is the combination of two diuretics, such as a diuretic that acts on loop and thiazide.

Resistance to diuretics is challenging to treat and may require higher doses to achieve the same effect.

Prescription and natural diuretics help promote well-being. There is even the possibility that diuretics can help you lose weight. Talk to your doctor to see what is the best diuretic for you.

For high blood pressure

Commonly known as “water pills,” these drugs help your kidneys remove excess water and salt from your body through your urine.

The pressure inside will be less because it has less total fluid in the blood vessels, such as a garden hose that does not turn on completely. This also makes it easier for your heart to pump.

They are usually the first type of medication that your doctor will try to control your blood pressure.

Name (s

It will often start with a thiazide diuretic:

  • Chlorthalidone (Hygroton).
  • Chlorothiazide (Diuril).
  • Hidroclorotiazida o HCTZ (Esidrix, Hydrodiuril, Microzide).
  • Indapamida (Lozol).
  • Metolazona (Mykrox, Zaroxolyn).

Others that your doctor may prescribe are:

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

While taking diuretics

Tell your doctor what medications (prescription and over-the-counter), supplements, and herbal remedies you use. Also, tell him about other medical problems you have.

You may want to monitor your blood pressure regularly and 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.

Side effects

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 risk becoming dehydrated, and simply drinking more fluids may not be enough. Call your doctor if you are very thirsty or have a parched mouth, your urine is dark yellow, you do not urinate too much, or you have constipation or 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 weak or cause muscle cramps or headaches.

It is rare, but your heart may speed up (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, leading 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.


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. Moreover, many pass into breast milk, which can dehydrate the baby.

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

Thiazide diuretics:

Thiazide diuretics are used as monotherapy or may be administered in conjunction with other antihypertensive agents. Thiazide diuretics inhibit the reabsorption of sodium and chloride, mainly in the distal tubules. Long-term use of these medications can cause hyponatremia.

They also increase the excretion of potassium and bicarbonate and decrease the excretion of calcium and the retention of uric acid. Thiazides do not affect normal blood pressure.

Note that all available loop and thiazide diuretics, except for ethacrynic acid, possess a sulfonamide group, which has significant clinical relevance for those individuals with allergies to sulfonamide agents.

Hidroclorotiazida (Microzide):

Hydrochlorothiazide is approved for the treatment of hypertension, alone or in combination with other antihypertensive agents.

Unlike potassium-sparing diuretics, hydrochlorothiazide can be used in patients who can not risk the development of hyperkalemia, including patients taking ACE inhibitors.

Hydrochlorothiazide is available as oral tablets or capsules in doses ranging from 12.5 to 50 mg. The usual dose is 12.5 mg administered alone or combined with other antihypertensive drugs, with a maximum of 50 mg daily. Doses greater than 50 mg are associated with hypokalemia.

Chlorthalidone (Thalitone):

Chlorthalidone is indicated for the treatment of hypertension, either alone or in combination with other antihypertensive drugs. The initial dose is 25 mg in a single daily dose.

The dose can be adjusted to 50 mg if the clinical response is not adequate. If additional control is required, increase the amount to 100 mg once a day, or a second antihypertensive medication may be added.

Doses greater than 100 mg per day generally do not increase effectiveness. The increases in serum uric acid and hypokalemia are related to the amount in the range of 25-100 mg/day.

Metolazone (Zaroxolyn):

Metolazone is approved for treating hypertension alone (uncommon) or with other antihypertensive drugs. The initial dose for hypertension is 2.5 to 5 mg, administered once a day.

Metolazone does not decrease the glomerular filtration rate or renal plasma flow and maybe a more practical option for patients with renal insufficiency.


Indapamide is not chemically a thiazide, although its structure and function are very similar. The drug increases the excretion of sodium, chloride, and water by inhibiting the transport of sodium ions through the renal tubule.

It is believed that the hypovolemic action of indapamide is responsible for the beneficial cardiovascular effects of the drug. The half-life of indapamide is approximately 14 hours, so the medication can be taken only once a day. Adverse effects tend to be somewhat milder than thiazides.

Diuretic, potassium saving:

Potassium-sparing diuretics interfere with the reabsorption of sodium in the distal tubules (mainly in the region of the collecting duct of the nephron), decreasing the secretion of potassium. Potassium-sparing diuretics have a weak diuretic and antihypertensive effect when used alone.


Triamterene is used alone or with other medications (often a kaliuretic diuretic such as hydrochlorothiazide) to treat edema and high blood pressure.

Because triamterene increases potassium levels, caution is required when combined with ACE inhibitors, angiotensin receptor blockers, aliskiren, and other medications that increase potassium levels.

The potassium level should be monitored at the beginning of the treatment, the dose change, and during the disease that affects kidney function. The recommended dose is 100 mg twice a day (the maximum is 300 mg/day).

Amiloride (Midamor):

Amiloride is a potassium-sparing drug (antiacaliuretic) which, compared to thiazide diuretics, has weak natriuretic, diuretic and antihypertensive activity.

It is approved for hypertension or congestive heart failure as an adjuvant treatment with thiazide diuretics or other kaliuretic diuretic agents.

It is not chemically related to other known diuretic or antiacaliuretic agents. Amiloride has little diuretic or antihypertensive additive effect when added to a thiazide diuretic.

Amiloride can be administered in 5-10 mg per day in 1-2 divided doses for hypertension.

Amiloride has a black box warning for hyperkalemia, which, if not corrected, is potentially fatal. This incidence is more significant in patients with renal insufficiency or diabetes mellitus and the elderly.

Hand diuretics:

Loop diuretics act on the ascending branch of the loop of Henle, inhibiting the reabsorption of sodium and chloride.

Loop diuretics are highly bound to proteins and, therefore, enter the urine mainly by tubular secretion in the proximal tubule rather than glomerular filtration.

Loop diuretics are commonly used to control volume retention.

Generally, thiazide diuretics are recommended for most patients diagnosed with hypertension; however, loop diuretics are prescribed more frequently for patients with a decreased glomerular filtration rate or heart failure.

When used as monotherapy, loop diuretics do not reduce blood pressure as effectively as thiazide diuretics, especially if dosed once a day.

Note that all available loop and thiazide diuretics, except for ethacrynic acid, possess a sulfonamide group, which has significant clinical relevance for those individuals with allergies to sulfonamide agents.

Furosemide (Lasix):

Furosemide is approved for treating hypertension alone (uncommon) or in combination with other antihypertensive agents. Hypertensive patients who can not be adequately controlled with thiazides will probably not be adequately controlled with furosemide alone.

The initial dosage recommendations for hypertension are generally 80 mg (divided into 40 mg twice daily). If the clinical response is insufficient, additional antihypertensive drugs can be added.

Patients should be carefully monitored because furosemide is a potent diuretic. If it is administered in excessive amounts, it can cause a profound diuresis with depletion of water and electrolytes. Furosemide is available as an oral tablet and injection solution.

Torsemida (Demadex):

Torsemide can be used as monotherapy or in combination with other antihypertensive agents. The initial dose is 5 mg once a day. The amount can be titrated to 10 mg once a day.

An additional antihypertensive agent may be needed if an adequate response is not observed. Torsemide is available as an oral tablet and injection solution.


The FDA approves Bumetanide for the treatment of edema. It is also used as not indicated for the treatment of hypertension. The usual dose range of Bumetanide for hypertension is 0.5-2 mg/day, given once or twice a day.