Discussing Diuretics

Diuretics: What You Need to Know About Them
Hypertension is when the systolic blood pressure reading is more than 140mmHg and the diastolic blood pressure reading is more than 90mmHg on two separate occasions when the person is calm and in a normal state. About 1.3 billion people have high blood pressure, and almost two-thirds of them live in countries with low or middle incomes. In 2015, it was found that 1 in 4 men and 1 in 5 women had high blood pressure. If blood numbers aren’t checked and kept in check, they can cause problems like kidney failure, heart failure, aneurysms, stroke, and dementia. (Mishra,2016). Hypertension is treated with a mix of drugs from different classes that work well together. These drugs may include calcium channel blockers, beta-blockers, alpha-blockers, angiotensin II receptor blockers, alpha II receptor agonists, angiotensin-converting enzyme inhibitors, and diuretics. By making you pee more, diuretics lower the amount of fluid in your body. This lowers the volume of your blood, which in turn lowers your blood pressure. Diuretics are further split into three groups based on where they work on the kidney nephrons: thiazide diuretics, loop diuretics, and potassium-sparing diuretics. Because of this, they act in different ways.

Thiazide diuretics

Most of the time, they are made up of hydrochlorothiazide (HCTZ), chlorthalidone, and indapamide.

Pharmacodynamics

They block the sodium-chloride channel in the proximal part of the distal convoluted tubule (DCT). This reduces the amount of sodium that crosses the lumen, which slows down the sodium-potassium pump and increases the amount of sodium in the distal end of the distal convoluted tubules and collecting tubules. When the sodium chloride channels are blocked, the sodium-calcium channels take in more calcium to make up for the extra sodium. So, the body doesn’t get rid of much calcium.

Thiazide diuretics come with some risks

The first affect of using a thiazide diuretic is hypokalemia, which is caused by the action of Na/K on aldosterone at the collecting tubule. Potassium is important for how cells work, so this needs to be watched. Hyponatremia can also happen because thiazide diuretics make you pee more, which makes you lose a lot of sodium. As we’ve already talked about, sodium levels drop by a lot when you pee more. Hyperuricemia may also increase the chance of gout by making the side effects worse. They use the OAT1 and OAT4 anion exchanger systems to directly take up urate in the proximal tubule.

Burnier, Bakris, and Williams (2019) say that hypercalcemia can happen when thiazide diuretics are used to treat high blood pressure. This is because when the sodium chloride channels are closed, there is an exchange for sodium. So, calcium ions are taken back up into the interstitium to make up for the lower sodium levels in the interstitium. Because of this, the pee has very little calcium in it. The loss of both hydrogen ions and potassium ions in the collecting tube causes metabolic alkalosis, which is a low-potassium state. Since thiazide diuretics are made from sulfa, people who are allergic to sulfur may have a rash, hives, angioedema, anaphylaxis, trouble breathing, or a headache if they take them.

Changes in pathophysiology to think about when giving

The digestive system gets rid of indapamide, but the distal convoluted tubule gets enough of it to do its job. Patients with liver problems may be given smaller doses of indapamide because taking too much of it could hurt the liver even more. Thiazide should be given in low amounts because it can cause low sodium and potassium levels, especially in older people. Sodium and potassium levels should be checked more often in people taking thiazides to avoid problems.

Potassium-sparing diuretics

Diuretics that save potassium include Amiloride, Eplerenone, spironolactone, and triamterene.

Pharmacodynamics

They work by sticking to epithelial sodium channels, which stops sodium ions from being reabsorbed. This is how amiloride and triamterene work. They also work by blocking aldosterone receptors. (spironolactone, eplerenone). Since potassium ions are lost through pee, this step reduces the amount of potassium that is lost too quickly. (Burnier, Bakris & Williams, 2019)

Risks of diuretics that keep potassium in the body

When potassium-sparing diuretics are used, the risks related to potassium are the opposite of what they are when thiazide diuretics are used. This is because potassium-sparing diuretics increase the risk of hyperkalemia. This happens because potassium-sparing diuretics work in the collecting tube to stop potassium ions from leaving the body in the urine. Hyperkalemia can cause irregular heartbeats, numbness and tingling, muscle weakness, and feeling sick and throwing up. Hyponatremia can also happen when not enough sodium is reabsorbed in the collecting tubules. When this happens, the body gets rid of too much sodium through the urine. Spironolactone can cause impotence, menstrual problems, gynecomastia, and a lower libido when it binds to non-selective estrogen and progesterone (aldosterone) hormones. Metabolic acidity can also happen. This can happen because there is a greater chance of vomiting, which means that bicarbonate ions are lost. (Burnier, Bakris & Williams, 2019).

Changes in pathophysiology to think about when giving

Since spironolactone only works for a short time, it should be taken with other drugs, like the loop diuretic furosemide. Only 3% of sodium ions can’t be reabsorbed. Because of this, potassium-sparing diuretics don’t have much of a natriuretic effect and need to be taken with other diuretics. When writing prescriptions, you should also keep an eye on the potassium levels to avoid hyperkalemia and the problems that come with it. (Roush & Sica,2016).

Also, when giving these types of diuretics, it’s important to think about the client’s sexual life. For example, spironolactone binds to aldosterone hormones without being selective, which can lower the libido and lead to impotence. So, it’s very important for the health care worker to think about these kinds of people who are worried about their sexual lives and give them the right advice. Gastric upset can also cause peptic ulcers, so special care should be taken for people who already have them because it can make them worse.

Loop diuretics

Furosemide, bumetanide, ethacrynic acid, and torsemide are all examples of loop diuretics.

Pharmacodynamics

Loop diuretics stop the sodium/potassium/chloride co-transporters (Na/K/2Cl) in the thick ascending loop of Henle. As a result, there are more sodium ions in the thick ascending loop of Henle. This makes the effect of epithelial sodium channels that cause potassium to be reabsorbed into the lumen of the collecting tubule even stronger. About 25% of sodium ions are kept in the ultra-filtered blood, so it has a much stronger effect on urination than other diuretics.(Roush & Sica,2016).

Risks of diuretics that keep potassium in the body

Hypokalemia can happen when you lose potassium through your urine because the Na/K/2Cl co-transporters are blocked. This happens when you lose more sodium through your urine. This can cause problems linked to hypokalemia that can be bad for the patient’s health. Hypokalemic metabolic alkalosis can also happen if the patient loses hydrogen ions because he or she has to go to the bathroom more often because sodium ions are lost through pee more quickly than through other diuretics. Hyperuricemia can also happen because loop diuretics are released by peritubular capillaries, which are also where uric acids are actively secreted. This can cause gouty arthritis because too much uric acid builds up in the body when two things try to get out at the same time. (Malha & Mann, 2016). Ototoxicity is also a risk, and using aminoglycosides may make it worse. Because of this, using these two types of drugs together should be illegal. Furosemide is a sulfa drug, so people who are allergic to sulfur may have hypersensitivity responses like rashes, hives, angioedema, and trouble breathing or wheezing when they take it.

Changes in pathophysiology to think about when giving

Loop diuretics are called “high ceiling diuretics” because they are thought to have the biggest natriuretic effect. This means that they make you pee out a lot of water, which can lead to low fluid levels in the body (hypovolemia). Since both can harm the ears, aminoglycosides and loop diuretics shouldn’t be given together. Since sodium is the ion that is lost the most in pee, it is important to keep an eye on it to avoid hyponatremia. Since uric acids are kept more, they should be checked. Loop diuretics should not be given with lithium because they slow down the kidneys’ ability to get rid of lithium. This can cause lithium poisoning.

Synopsis of the Article

In the past, diuretics were thought of as first-line drugs for treating high blood pressure. However, as better and more effective drugs were made, diuretics were not thought of the same way they were before. Thiazide and diuretics that are similar to thiazide are often the first drugs used to treat people with main high blood pressure. Still, most doctors don’t recommend them more than the other diuretics. People have noticed that hydrochlorothiazide works for a shorter amount of time than other thiazide and thiazide-like diuretics. Spironolactone was praised for how well it worked on resistant high blood pressure. It was said that eplerenone had a big effect on high blood pressure. Loop diuretics were thought to be best for people with chronic kidney disease and a blood creatinine level of 1.5 mg/dl or higher. Many experts say that indapamide is a more effective and easier-to-take medication for people with high blood pressure. It also does a better job than enalapril of reducing left ventricular enlargement. (Mishra,2016).

Diuretics and how well a patient does

The dose-response relationship between loop diuretics and how people do after they leave the hospital is not known. Short-term use of diuretics is not a reliable way to predict a return to the hospital for heart failure. It is still not clear how diuretics affect the clinical results of people with heart failure. Higher doses of diuretics have been linked to severe clinical effects for both hospitalized and outpatient patients. (Ahluwalia & Bangalore2017).

In conclusion, hyponatremia can be caused by diuretics because they all involve getting rid of sodium through pee. Not just one type of diuretic is used to treat high blood pressure. For example, thiazide diuretics can work well with potassium-sparing loop diuretics to avoid low potassium levels. Because of this, anti-hypertensive drugs from different classes need to be used together. It is important to keep track of urea and electrolytes because different salts and uric acid are gained and lost.

References

Ahluwalia, M., & Bangalore, S. (2017). Management of hypertension in 2017: targets and therapies. Current opinion in cardiology, 32(4), 413-421.

Burnier, M., Bakris, G., & Williams, B. (2019). Redefining diuretics use in hypertension: why select a thiazide-like diuretic? Journal of hypertension, 37(8), 1574.

Malha, L., & Mann, S. J. (2016). Loop diuretics in the treatment of hypertension. Current hypertension reports, 18(4), 27.

Mishra, S. (2016). Diuretics in primary hypertension–reloaded.

Roush, G. C., & Sica, D. A. (2016). Diuretics for hypertension: a review and update. American journal of hypertension, 29(10), 1130-1137.

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