what are loop diuretics

Full Answer

What is an example of loop diuretic?

Examples of loop diuretics include: Bumetanide (Bumex) Ethacrynic acid (Edecrin) Furosemide (Lasix)

What are the 4 loop diuretics?

Available loop diuretics include bumetanide, ethacrynic acid, furosemide, and torsemide.

What are loop diuretics used for?

Loop diuretics are medications used in the management and treatment of fluid overload conditions such as heart failure, nephrotic syndrome or cirrhosis, and hypertension, in addition to edema.

What is the difference between a diuretic and a loop diuretic?

Thiazides decrease the urinary excretion of calcium, while loop-diuretics have the opposite effect. The possibility of loop-diuretic induced osteopenia cannot be ruled out, which should be considered when choosing between thiazides and loop-diuretics for the treatment of mild to moderate CHF.

Why is it called loop diuretic?

They work by making the kidneys pass out more fluid. They do this by interfering with the transport of salt and water across certain cells in the kidneys. (These cells are in a structure called the loop of Henle - hence the name loop diuretic.

Which drug is the most commonly used loop diuretic?

The most commonly used loop diuretics are furosemide, bumetanide, and torsemide, which are sulfonamide derivatives. Ethacrynic acid is rarely used but is an alternative in patients who have a hypersensitivity reaction to a typical loop diuretic. (See 'Hypersensitivity reactions' below.)

What are the 3 types of diuretics?

The three types of diuretic medications are called thiazide, loop, and potassium-sparing diuretics. All of them make your body excrete more fluids as urine....Potassium-sparing diureticsamiloride.triamterene (Dyrenium)spironolactone (Aldactone)eplerenone (Inspra)

Why do loop diuretics cause heart failure?

Administration of loop diuretics to patients with heart failure has been shown to activate the renin-angiotensin-aldosterone system and the sympathetic nervous system, both of which are known to play a fundamental role in heart failure progression.

What is the major problem with loop diuretics?

As a result, the loop diuretics are used more for the therapy of edema than long term therapy of hypertension. Common and shared side effects of the loop diuretics include dizziness, headache, gastrointestinal upset, hypernatremia, hypokalemia and dehydration.

Who should not take loop diuretics?

Don't take diuretics if you have trouble urinating, or if you're allergic to the active or inactive ingredients found in the medication. Ask your doctor if you should avoid or be cautious using diuretics if you: Have severe liver or kidney disease. Are dehydrated.

What is the common name for loop diuretic?

Generic and brand names of loop diuretics include: Bumetanide. Bumex. Burinex.

When should you avoid loop diuretics?

Loop diuretics are contraindicated in patients with hypokalemia (only to be administered after correction), severe hyponatremia, hypotension, azotemia, oliguria/anuria, and hepatic coma. It is also contraindicated in any situation where fluid depletion is foreseen, such as surgery.

What are the 5 diuretics?

Diuretics are drugs that increase the flow of urine. They are commonly used to treat edema, hypertension, and heart failure. Typically, the pharmacological group consists of five classes: thiazide diuretics, loop diuretics, potassium-sparing diuretics, osmotic diuretics, and carbonic anhydrase inhibitors.

What is the common name for loop diuretic?

Generic and brand names of loop diuretics include: Bumetanide. Bumex. Burinex.

Which loop diuretic is best for heart failure?

Furosemide is by far the most common oral loop diuretic, but patients with resistance to oral furosemide therapy may benefit from trials with second-generation oral loop diuretics (bumetanide and torasemide). These may be more efficacious, due to their increased oral bioavailability and potency.

What is the classification of loop diuretics?

Loop diuretics are a class of medications used to cause diuresis, or increased urine flow. They differ from other types of diuretics in how they increase urine production. Other diuretic classes include thiazide diuretics, carbonic anhydrase inhibitors, and potassium-sparing diuretics.

What is the role of a pharmacist in a loop diuretic?

Pharmacists should always verify the dosing of these and all drugs and perform medication reconciliation for drug-drug interactions. Healthcare workers are responsible for keeping up with current loop diuretic recommendations and providing safe practice to their patients. Nursing can monitor treatment compliance and verify therapy effectiveness as well as monitor for adverse drug reactions. Nursing and pharmacy will report all concerns to the physician and the rest of the interprofessional team, operating collaboratively to achieve optimal therapeutic results. Clinicians, pharmacists, and nurses all need to function as a cohesive interprofessional team when patients receive loop diuretics so therapeutic outcomes can be maximized while limiting or eliminating interactions and adverse effects. [Level 5]

How much bumetanide is in a pill?

Bumetanide comes in oral tablets of 0.5, 1 and 2 mg doses. IV solution is 0.25 mg/mL. Ethacrynic acid is available with oral tablets of 25 mg and in a powder form for injections at 50 mg. Bioavailability varies between each member of the loop diuretics.

What is loop diuretic?

Loop diuretics are medications used in the management and treatment of fluid overload conditions such as heart failure, nephrotic syndrome or cirrhosis, and hypertension, in addition to edema.

How long does furosemide last?

The half-life for furosemide is 1.5 to 2 hours but can be up to 2.6 hours in those with renal/hepatic dysfunction or heart failure. Bumetanide has a half-life of 1 hour and can be near 1.3 to 1.6 hours in those with renal/hepatic dysfunction or heart failure.

What forms do loop diuretics come in?

Several loop diuretics come in IV and oral forms.

What is the first line of treatment for heart failure?

According to the 2014 ACCF/AHA Guideline for the Management of Heart Failure, patients admitted with heart failure (Stage C) with signs of fluid overload should be treated with intravenous loop diuretics to reduce morbidity. The ACCF/AHA has given a Class I recommendation for the use of diuretics (including loop diuretics) as the first-line treatment of heart failure with reduced left ventricular ejection fraction (HFrEF) and volume overload. [1][2]

How do loop diuretics affect the apical membrane of the loop of Henle?

Loop diuretics induce its effect by competing with chloride to bind to the Na-K-2Cl (NKCC2) cotransporter at the apical membrane of the thick ascending limb of the loop of Henle and blocking the cotransporter, which inhibits the reabsorption of sodium and chloride. By inhibiting NaCl reabsorption, tonicity in the interstitium decreases, and free water excretion increases as a result. Blocking of the NKCC2 cotransporter makes potassium unable to be reabsorbed back into the lumen, which results in the loss of calcium and magnesium ions. [1]

What is a loop diuretic?

Loop diuretics are medications used to treat fluid overload conditions such as heart failure, nephrotic syndrome or cirrhosis, and hypertension, in addition to edema . Loop diuretics work to lower the fluid buildup in the body by reducing sodium reabsorption in the loop of Henle, thereby causing the elimination of water and sodium from the body.

What is the loop of henle?

The loop of Henle is a long U-shaped structure of the kidney, responsible for recovering sodium and water from the urine. Excess fluid and sodium retention can lead to increased blood pressure .

What is the cotransporter of Na-K-2Cl?

The transporter inhibited by loop diuretics is one member of the cation chloride cotransporter family ( 426 ). This protein as the Na-K-2Cl cotransporter, second isoform, NKCC2 (or alternatively as the bumetanide-sensitive cotransporter, first isoform [BSC1]), is encoded by the gene SLC12A1. It is a protein with 12 putative membrane-spanning domains that is expressed at the apical membrane of thick ascending limb ( 241) and macula densa (MD) cells ( 343 ). It lies in parallel with a K channel (ROMK, Kir1.1) that permits potassium to recycle from the cell to the lumen ( 212 ). The asymmetrical orientation of channels (apical versus basolateral) and the action of the Na,K-ATPase and Na-K-2Cl cotransporter combine to create a transepithelial voltage that is oriented with the lumen positive, with respect to the interstitium. This lumen-positive potential drives absorption of Na, Ca and Mg via the paracellular pathway. The paracellular component of Na reabsorption comprises 50% of the total transepithelial Na transport by thick ascending limb cells ( 206 ); it should be noted, however, that both the transcellular and the paracellular components of Na transport are inhibited by loop diuretics, the former directly and the latter indirectly. The thick ascending limb is virtually impermeable to water. The combination of solute absorption and water impermeability leads to dilution of tubule fluid.

What is the effect of loop diuretics on a thick limb cell?

The predominant effect of loop diuretic drugs is to inhibit the electroneutral Na-K-2Cl cotransporter at the apical surface of thick ascending limb cells . The loop of Henle, defined as the region between the last surface proximal segment and the first surface distal segment, reabsorbs from 20% to 50% of the filtered Na and Cl load (250 ); approximately 10% to 20% is reabsorbed by thick ascending limb cells. The model in Fig. 7 shows key components of Na, K, and Cl transport pathways in a thick ascending limb cell. Although mechanisms of Na and Cl transport have been discussed more thoroughly in other chapters in this volume, some important points deserve emphasis. First, as in other nephron segments, the Na,K-ATPase at the basolateral cell membrane maintains the intracellular Na concentration low (approximately 10-fold lower than interstitial) and the K concentration high (approximately 20-fold higher than interstitial). Potassium channel (s) in the basolateral cell membrane permit K to diffuse out of the cell, rendering the cell membrane voltage oriented with the intracellular surface negative, relative to extracellular fluid ( 356 ). A chloride channel in the basolateral cell membrane ( 481) and a barium-sensitive K-Cl cotransporter permit Cl to exit the cell ( 117 ).

What is loop diuretic tolerance?

Long-term loop diuretic tolerance refers to the resistance of their action as a consequence of distal nephron segment hypertrophy and enhanced sodium reabsorption that follows increased exposure to solutes not absorbed proximally.39 This problem can be addressed by combining loop and thiazide diuretics as the latter block those responsible distal nephron sites. Diuretic resistance refers to edema that is or has become refractory to a given diuretic. An algorithm for diuretic therapy in patients with edema caused by renal, hepatic, or cardiac disease is outlined in Figure 7.11. Diuretic resistance can be due to several causes. Chronic kidney disease is associated with a decreased tubular delivery and secretion of diuretics, which subsequently reduces their concentration at the active site in the tubular lumen. In nephrotic syndrome, it was once thought that the high protein content of tubular fluid increases protein binding of furosemide and other loop diuretics and therefore inhibits their action. However, recent data suggest that urinary protein binding does not affect the response to furosemide. 42 As explained earlier, arterial underfilling that takes place in cirrhosis and CHF is associated with diminished nephron responsiveness to diuretics because of increased proximal tubular sodium reabsorption, leading to decreased delivery of sodium to the distal nephron segment sites of diuretic action. NSAIDs block prostaglandin-mediated increases in renal blood flow and increase the expression of the sodium-potassium-chloride cotransporters in the thick ascending limb.

What is furosemide used for?

Furosemide, a loop diuretic drug, indicated for the treatment for hypertension, edema, and nephrotic syndrome, was studied to evaluate the ability of NIR chemical imaging (NIR-CI), NIR, Raman, and ATR-IR spectroscopy to quantify three polymorphic forms (I, II, and III) in ternary powder mixtures.26 For this purpose, PLS regression models were developed, and different data preprocessing algorithms such as normalization, SNV, multiplicative scatter correction (MSC), and first to third derivatives were applied to reduce the influence of systematic disturbances. This study proves that NIR-CI, NIR, and Raman spectroscopies are well suited to quantify forms I–III of furosemide in ternary mixtures, as shown in Fig. 4. Because of the pressure-dependent conversion of form II to form I, ATR-IR was found to be less appropriate for an accurate quantification of the mixtures.

How to reduce postdiuretic sodium retention?

Salt restriction is the key approach to lessening postdiuretic sodium retention. Further approaches to antagonize diuretic resistance include increasing the dose of loop diuretic, administering more frequent doses, and using combination therapy to sequentially block more than one site in the nephron as that may result in a synergistic interaction between diuretics. Highly resistant edematous patients may be treated with ultrafiltration.

What is a loop diuretic?

A loop diuretic is an effective adjuvant to ACE inhibitor or ARB therapy through promotion of increased sodium excretion in the nephron.

Is torsemide a diuretic?

Torsemide is a pyridine sulfonylurea loop diuretic. Its relative potency as an inhibitor of the Na+ /K + /2Cl − symporter, is as follows: Bumetanide > Piretanide > Torsemide > Furosemide Knauf and Mutschler (1998). As with other loop diuretics, the natriuretic and diuretic effect of torsemide results from inhibition of the reabsorption of sodium by this transporter. The resultant decline in the osmolality of the kidney medulla contributes to the reduction in reabsorption of water and an increased diuresis. The indications for torsemide are similar to those of the other loop diuretics. The drug is well absorbed after oral administration and has a longer plasma terminal half-life than other loop diuretics. Unlike furosemide, torsemide is well absorbed in those with heart failure Sica (2003). Torsemide is highly bound to plasma proteins, principally albumin, and undergoes extensive metabolism (about 80%) in the liver Werner et al (2008). It is actively secreted by the renal proximal tubules into the lumen where it interacts with the Na + /K + /2Cl − symporter on the luminal border of the thick ascending limb of the loop of Henle. Torsemide is less likely to cause hypokalemia than other loop diuretics because of its anti-aldosterone effect in the kidney Luft (1993). Torsemide is reported to display an antihypertensive effect at doses below its diuretic effect Knauf and Mutschler (1998). http://chem.sis.nlm.nih.gov/chemidplus/jsp/common/ChemInfo.jsp?type=names

What is the role of loop diuretics in pharmacokinetics?

Pharmacokinetics. Loop diuretics are highly protein bound and therefore have a low volume of distribution. The protein bound nature of the loop diuretic molecules causes it to be secreted via several transporter molecules along luminal wall of the proximal convoluted tubules to be able to exert its function.

How much furosemide is equivalent to 20 mg of torsemide?

A dose of 40 mg of furosemide is equivalent to 20 mg of torsemide and 1 mg bumetanide.

What is diuretic resistance?

Resistance. Diuretic resistance is defined as failure of diuretics to reduce fluid retention (can be measured by low urinary sodium) despite using the maximal dose of drugs. There are various causes for the resistance towards loop diuretics.

How much urine do you produce with diuretic infusion?

Diuretic dosages is adjusted to produce 3 to 5 litres of urine per day. Thiazide (blockade of sodium-chloride symporter), amiloride (blockade of epithelial sodium channels) and carbonic anhydrase inhibitors (blockade of chloride-bicarbonate exchanger pendrin) has been suggested to complement the action of loop diuretics in resistance cases but limited evidence are available to support their use.

Why are loop diuretics used?

They are primarily used in medicine to treat hypertension and edema often due to congestive heart failure or chronic kidney disease. While thiazide diuretics are more effective in patients with normal kidney function, loop diuretics are more effective in patients with impaired kidney function.

What is the name of the drug that blocks the action of loop diuretics?

Thiazide (blockade of sodium-chloride symporter), amiloride (blockade of epithelial sodium channels) and carbonic anhydrase inhibitors (blockade of chloride-bicarbonate exchanger pendrin) has been suggested to complement the action of loop diuretics in resistance cases but limited evidence are available to support their use.

What happens when you inhibit potassium recycling?

By inhibiting the potassium recycling, the voltage gradient is abolished and magnesium and calcium reabsorption are inhibited. By disrupting the reabsorption of these ions, loop diuretics prevent the generation of a hypertonic renal medulla.

What are the possible side-effects?

Side-effects are uncommon when routine low doses are used. The higher the dose, the greater the risk of side-effects developing. The leaflet which comes in the tablet package provides a full list of possible side-effects. So, it is important to read that leaflet if you are prescribed a loop diuretic. Common or serious possible side-effects include:

What are the different types of diuretics?

There are different types of diuretics. Loop diuretics are one type. They include furosemide , bumetanide and torasemide. Each comes in different brand names.

Why do you need loop diuretics?

Loop diuretics are commonly used in the treatment of heart failure. In this condition, fluid accumulates in your body, due to the heart not pumping blood around the body as well as it normally would.

What are the side effects of a loop diuretic?

Side-effects are uncommon when routine low doses are used. The higher the dose, the greater the risk of side-effects developing. The leaflet which comes in the tablet package provides a full list of possible side-effects. So, it is important to read that leaflet if you are prescribed a loop diuretic. Common or serious possible side-effects include: 1 The salt balance in the bloodstream sometimes being upset, which can cause a low blood level of potassium, sodium, and magnesium, and a high level of calcium. These effects may cause weakness, confusion and, rarely, abnormal heart rhythms to develop. You may be advised to have a blood test to check for these problems. 2 If you have diabetes or gout, these conditions may be made worse by diuretics. 3 An upset stomach 4 Dizziness on standing - due to too low blood pressure (hypotension).

How long does it take for a diuretic to work?

Most loop diuretics are taken once a day in the morning. The effect of making more urine usually starts within half an hour. So, you may find you need to go to the toilet a couple of times within a few hours of taking the tablet. However, the effect of passing extra urine wears off within about six hours. So, you will not have to get up in the night to make extra trips to the toilet.

How do diuretics work?

They work by making the kidneys pass out more fluid. They do this by interfering with the transport of salt and water across certain cells in the kidneys. (These cells are in a structure called the loop of Henle - hence the name loop diuretic. You have thousands of these loops in each kidney.)

What are the side effects of a salt bath?

These effects may cause weakness, confusion and, rarely, abnormal heart rhythms to develop.

What is the most common diuretic used for loops?

The most commonly used loop diuretics are furosemide, bumetanide, and torsemide, which are sulfonamide derivatives. Ethacrynic acid is rarely used but is an alternative in patients who have a hypersensitivity reaction to a typical loop diuretic. (See 'Hypersensitivity reactions' below.)

What is the purpose of loop diuretics?

Loop diuretics reduce sodium chloride (NaCl) reabsorption in the thick ascending limb of the loop of Henle. This is achieved by inhibiting the Na-K-2Cl carrier .

When to use intravenous loop diuretic?

Intravenous loop diuretic treatment is commonly employed when urgent diuresis is needed or when there is concern for poor gastrointestinal absorption. Continuous loop diuretic infusion is sometimes prescribed rather than intermittent bolus therapy ( figure 2 ). However, if a continuous infusion is used, it is important to begin with a bolus to assure that the patient is diuretic responsive and to achieve therapeutic drug concentrations. These issues are discussed elsewhere:

Where do loop diuretics enter the body?

The loop diuretics are highly protein bound and therefore enter the tubule primarily by secretion in the proximal tubule, rather than by glomerular filtration [1]. The most commonly used loop diuretics are furosemide, bumetanide, and torsemide, which are sulfonamide derivatives.

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Diuretics

Diuretics, also called water pills, are a common treatment for high blood pressure. Find out how they work and when you might need them.

When diuretics are used

Thiazide diuretics are recommended as one of the first drug treatments for high blood pressure.

Side effects

Diuretics are generally safe. Side effects include increased urination and sodium loss.

Overview

Mechanism of action

Pharmacokinetics

Clinical use

Resistance

Adverse effects

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