What are diuretics?

Diuretics, also known as water pills, help release excess fluid from the body through urine. This action is used to treat conditions such as high blood pressure, congestive heart failure, edema (fluid retention in the body), and other conditions. Diuretics pull sodium from the kidneys into the urine. This helps reduce overall fluid levels, which can lower blood pressure.

Diuretics are commonly supplied as oral capsules. The diuretic drugs used to treat high blood pressure and heart failure are only available via prescription. Several over-the-counter options are available for purchase without a prescription, but the FDA has not approved any of these for treating heart conditions. OTC diuretics are used for the treatment of bloating symptoms.

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What are diuretics used for?

Diuretics are prescription drugs most commonly used as a first-line treatment for high blood pressure (hypertension). There are three different types of diuretics, and each one acts differently on the kidneys. In general, these medications work by helping the kidneys pull excess sodium and fluid from blood cells into the urine. The body then releases this extra salt and water through the urine stream.

Excess sodium in the body causes your body to retain more fluid. The more fluid that is held in your blood cells, the greater the pressure on the blood vessels. Think of fluid retention as plugged-up plumbing. If the pipes in your house cannot move water efficiently, leftover water builds up in the plumbing. This puts pressure on the pipes, potentially causing them to rupture. Your blood vessels work similarly. The excess fluid makes it harder for your vascular system to move blood throughout the body. This leads to increased blood pressure and other complications. Diuretics promote the process of diuresis, or the natural excretion of unnecessary substances in the body via urine.

High blood pressure is a dangerous and potentially fatal condition in which the heart is met with too much resistance from blocked or narrowed arteries as it tries to pump blood and oxygen around your body. High blood pressure can lead to various serious health issues, including heart attack, heart failure, stroke, and many more complications when not treated. Nearly half of Americans have high blood pressure, and heart disease is the leading cause of death in the United States.

In addition to their use as a treatment for high blood pressure, diuretics may be prescribed to treat other conditions, such as:

• Congestive heart failure
  
• Kidney disease
  
• Liver disease (like cirrhosis)
  
• Edema (fluid retention)
  
• Glaucoma
  
  

Diuretics may be prescribed alone or in conjunction with another form of medication. For example, a thiazide diuretic may be given with a beta-blocker, calcium channel blocker, or angiotensin-converting enzyme inhibitor (ACE) to lower the amount of fluid in the body while also relaxing the blood vessels.

Some patients may be prescribed a potassium supplement while taking a thiazide or loop diuretic. Diuretics can deplete potassium levels in the blood (hypokalemia). Potassium supplements help maintain this chemical balance and prevent complications caused by a lack of potassium in the blood.

What are the different kinds of diuretics?

There are three classes of diuretics. Each works on a different part of the kidneys, but all are used to produce the same effect. They all pull excess sodium and fluid from blood cells into the urine, releasing them from the body when you pee. The different classes of diuretics are detailed below:

Thiazide Diuretics: Thiazide diuretics are most often used to treat high blood pressure. They aid in excess fluid secretion by pulling sodium and water from the blood cells into the kidney and urine streams. Thiazides remove a moderate amount of fluid from the body and are safe to use over a long period of time. A health care provider may prescribe another form of blood pressure medication (like ACE inhibitors or angiotensin receptor blockers) and a potassium supplement to take along with a thiazide diuretic.

Examples of thiazide diuretics include:

• Chlorothaliadone (generic for Thalitone)
  
• Hydrochlorothiazide (generic for Esidrix)
  
• Indapamide (generic for Lozol)
  
• Chlorothiazide (generic for Diuril)
  
• Bendroflumethiazide
  
• Metolazone
  
  

Loop Diuretics: Loop diuretics are stronger than thiazide diuretics. These drugs work on the Loop of Henle (a tubule located in the kidneys) to release excess sodium and fluid from the kidneys via urine. Loop diuretics are usually prescribed for the treatment of heart failure.

Examples of loop diuretics include:

• Bumetanide (generic for Bumex)
  
• Furosemide (generic for Lasix)
  
• Torsemide (generic for Demadex)
  
• Ethacrynic acid (generic for Edecrin)
  
  

Potassium-sparing diuretics: Potassium-sparing diuretics work like thiazide diuretics while helping the body hold on to potassium. Certain potassium-sparing diuretics are known as “aldosterone antagonists” and work by blocking the action of the steroid hormone aldosterone on blood cells. Aldosterone can cause sodium and water retention, contributing to high blood pressure and other complications. By inhibiting aldosterone, these drugs help the body release excess fluid and sodium via urine.

Examples of potassium-sparing diuretics include:

• Spironolactone (generic for Aldactone)
  
• Triamterene (generic for Dyrenium)
  
• Amiloride (generic for Midamor)
  
• Eplerenone (generic for Inspra)
  
  

Carbonic anhydrase inhibitors, like acetazolamide, have diuretic properties that can be used to treat glaucoma and heart failure. These drugs are also prescribed to help manage the symptoms of epilepsy and altitude sickness.

What are the common side effects of diuretics?
Diuretics are among the most commonly prescribed drugs for treating high blood pressure. In general, their benefits outweigh any possible risks of adverse effects. However, diuretics have been shown to cause some adverse effects.

Common side effects of diuretic use include:

• Frequent urination
  
• Headache
  
• Nausea
  
• Dizziness
  
• Lightheadedness
  
• Increased blood sugar
  
• Muscle cramps
  
• Increased thirst
  
• Electrolyte imbalances
  
  

In some cases, diuretic use can lead to more serious complications. The release of sodium and fluid from the body can cause other important electrolytes (like potassium) to be lost too. Low potassium levels (hypokalemia) can cause an irregular heartbeat and muscle cramps. Inversely, using potassium-sparing diuretics can lead to excess potassium in the blood (hyperkalemia). Hyperkalemia can cause serious complications like an irregular heartbeat and renal impairment.

If you begin to experience a skin rash, hives, swelling, or difficulty breathing after taking a diuretic, you should seek medical attention immediately. These are early signs of an allergic reaction—a potentially life-threatening medical emergency.

Inform your provider if you are currently managing any medical conditions before starting treatment with a diuretic. You should also tell them about any and all medications and supplements you are taking before taking diuretics. This will help prevent any serious drug interactions.

Diuretic use may be discouraged if you:

• Take another form of blood pressure medication (like Digoxin)
  
• Take any antidepressant medication
  
• Have a history of low blood pressure (hypotension)
  
• Have a history of gout, diabetes, or lupus
  
• Have a history of kidney or liver problems
  
  

Diuretics are generally considered safe for pregnant and breastfeeding women. Even so, you should inform your health care provider if you are pregnant or become pregnant while taking diuretic medication.

Do I need a prescription for diuretics?

Yes. No FDA-approved diuretic drugs for hypertension or heart failure are available over the counter.

Providers on Sesame can write a prescription – or refill an existing one – during a virtual or in-person visit. Depending on the medication, you can arrange for same-day pickup at a pharmacy near you or order the medication to be delivered to your door for just $5. Book an online consultation with a real, licensed provider on Sesame today to determine whether or not diuretics are right for you.

Looking for more information? Check out our blog for articles about heart health and heart-healthy recipes.

If you have a family history of hypertension or are experiencing symptoms of cardiovascular disease, you should book a video doctor visit with a licensed health care provider on Sesame to discuss your symptoms and possible treatment options.

Sources:

• Arumugham VB, Shahin MH. Therapeutic Uses Of Diuretic Agents. https://www.ncbi.nlm.nih.gov/books/NBK557838/.
  
• LiverTox: Clinical and Research Information on Drug-Induced Liver Injury. https://pubmed.ncbi.nlm.nih.gov/31644115/.(2021).
  
• Ellison D. H. Clinical Pharmacology in Diuretic Use. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6682831/.
  
• Huxel C, Raja A, Ollivierre-Lawrence MD. Loop Diuretics. https://www.ncbi.nlm.nih.gov/books/NBK546656/.
  
• National Cancer Institute. Diuretic. https://www.cancer.gov/publications/dictionaries/cancer-terms/def/diuretic.
  
• Corliss, Julie. Tips for taking diuretic medications. health.harvard.edu 2019.
  

Sesame content is not intended to be a substitute for professional medical advice, diagnosis or treatment. If you have a medical concern, it is critical to seek the advice of your physician or another qualified health provider with any questions. If you are facing a medical emergency, call 911 or visit the nearest emergency room immediately.

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