Hey there future nurses, it's Christine from Nurse in the Making and today we're going to talk about diuretics. There are four types of diuretics. Loop, thiazide, potassium sparing, and osmotic diuretics. Though they all work differently, they work towards the same goal, which is to diurese the body or get rid of excess fluid. Diuretics act on the kidneys to stimulate urine production, causing you to pee a lot.
This decreases the fluid in your body. You can remember this by the memory trick, diuretics think dry inside. Let's talk about why diuretics are given.
Diuretics are most commonly used to treat heart failure. In heart failure, fluid is backing up into the system because the heart is weakened. So heart failure patients have fluid retention, where the body is holding onto excess water.
Heart failure patients commonly have massive amounts of edema caused by this fluid retention. So diuretics are used to pull some of this fluid off the body and decrease edema. Heart failure actually can cause hypertension, which is why diuretics are also considered a type of antihypertensive. Remember, the more volume in the vessels means more pressure on them, aka hypertension. Diuretics are also used for those who have chronic kidney disease or CKD.
These patients'kidneys are injured and the kidneys'jobs are to excrete excess fluid through the urine. When the kidneys can't do their job, all this excess fluid is staying in the body. The kidneys are also not filtering out potassium, which can lead to hyperkalemia. So we use our potassium-wasting diuretics to help lower blood pressure and potassium levels in those with CKD.
The first type of diuretics are our loop diuretics. We are saved by the suffix because loop diuretics end in the suffix mide and nide. We have furosemide, brand name Lasix, which you will hear very often at clinicals. We have bumetanide and torsemide.
All diuretics work in the kidneys but each type of diuretic stimulates different parts of the kidneys. So loop diuretics inhibit reabsorption of sodium and chloride. The end goal of using diuretics is to rid the body of that excess fluid, not sodium. But loop diuretics use sodium to accomplish this end goal, because water always follows sodium. You can remember this by the memory trick where sodium goes, water flows.
So by taking sodium out of the vessels, you are removing water as well. Loop diuretics also cause potassium to be excreted through the urine. We call this potassium wasting diuretics, which I'll talk about more later. Loop diuretics are the most potent types of diuretics because they inhibit reabsorption in three parts of the kidneys, which makes their effect stronger than other diuretics. These three sites are the distal tubules, the proximal tubules, and the loop of Henle.
Remember when I said this diuretic causes potassium to be excreted? Well, this is why the major side effect of loop diuretics is that they are potassium wasting, which can cause hypokalemia or low potassium in the blood. A normal potassium level is 3.5 to 5.0.
We want to be in this range. We don't want to be too high or too low. Some nursing considerations for loop diuretics is that you want to monitor potassium levels.
Remember, this is a potassium wasting diuretic. If potassium is very low, you want to replace it with, well, potassium. You can replace potassium with an oral pill or through the intravenous route. Some things to note when administering potassium orally is that potassium chloride is an extended release tablet, and these should not be crushed or chewed.
You may see this done in the hospital, but the NCLEX does not want you to crush or chew these medications. Another thing is that you want to educate your patient to take this medication with a full glass of water. and with meals to decrease GI upset.
Some things to note when administering potassium intravenously is that you never want to administer potassium IV push. This could kill your patient. Potassium is a high alert medication.
It must be administered with an infusion pump and it must be diluted. Another thing to note is that you want to administer furosemide very slowly. If you administer it too quickly, it can cause ototoxicity. Ototoxicity is when the ears become damaged, which can lead to hearing loss, ringing in the ears, and other issues related to the ears. Now for thiazide diuretics.
We are saved by the suffix. Thiazide diuretics end in the suffix thiazide, which is really easy to remember. We have hydrochlorothiazide and chlorothiazide.
The mode of action is similar to loop diuretics in that they inhibit reabsorption of sodium and chloride, but they don't act on as many parts of the kidney as loop diuretics, which is why thiazide diuretics are not as strong. Thiazide diuretics act on the ascending portion of the loop of Henle. which is part of the loop of Henle.
Remember loop diuretics work on the entire loop of Henle. And it acts on the early distal tubule. Similar to loop diuretics, thiazide diuretics are also potassium wasting diuretics. So the major side effect is hypokalemia. Some nursing considerations for thiazide diuretics is that you want to monitor potassium levels.
Remember this is a potassium wasting diuretic. If potassium is very low, you can replace it with potassium. Some other nursing considerations with thigh-zye diuretics is you don't want to administer this medication in clients with gout. Thigh-zye diuretics may cause an increase in uric acid in the blood and we know gout attacks are caused by an increased uric acid in the blood. Patients with a sulfa allergy should also avoid thiazide diuretics.
This is because thiazide diuretics are sulfa-based and can cause those with a sulfa allergy to have an allergic reaction. Next is potassium-sparing diuretics, which, you guessed it, holds onto potassium. This is the opposite of lup and thiazide diuretics, which were potassium-wasting diuretics. The most common potassium sparing diuretic is called spurnolactone, brand name aldactone.
You can remember this by the memory trick S, think sparing. Spurnolactone blocks the effect of aldosterone. First, let's do a little review on what aldosterone is.
Aldosterone is a mineral corticoid that helps in fluid balance. If you have an increase in aldosterone, it will cause sodium and water retention. If there is a decrease in aldosterone, it will cause sodium and water excretion. So by blocking aldosterone, sodium and water will be eliminated from the body.
But remember, potassium is not excreted. It spares it and holds on to potassium. Since this is a potassium sparing diuretic, we want to monitor for hyperkalemia, which is a high potassium level.
You want to educate your patient to avoid eating foods high in potassium. They are at risk for hyperkalemia, so we don't want to increase their potassium levels even more. Some foods that contain potassium are green leafy veggies, raw carrots, melons, bananas, tomatoes, and orange juice.
You also want to educate them to avoid potassium supplements and salt substitutes. This is because most salt substitutes contain potassium chloride. The next diuretic is osmotic.
A very common osmotic diuretic is mannitol, brand name osmitrol. Osmotic diuretics increase the thickness of the filtrate in the kidneys so water can't be reabsorbed into the bloodstream. So it has nowhere to go but out of the body through urine.
Osmotic diuretics are not used for your classic hypertension, edema, and heart failure where the diuretic's trying to diurese the body and get rid of that excess fluid. Osmotic diuretics decrease swelling and pressure in the eyes and the brain, so they're used to treat cerebral edema and decrease interocular pressure in the eyes. Some nursing considerations to know is that mannitol is only administered IV.
The solution may crystallize, so be sure to check the solution before administering it. And you want to perform neuro assessments and level of consciousness if you're using it for cerebral edema. Now let's look at nursing considerations for all diuretics.
You want to educate your patient to take diuretics in the morning, not at night. You don't want your patient peeing all night long. This is called nocturia.
Nocturia, think night peeing. Diuretics cause orthostatic hypotension. So you want to educate your patient to make slow position changes and dangle their feet on the side of the bed or chair before getting up.
Another thing is to educate your patient on following a low-sodium diet. Sodium makes us retain water. You can remember this by the memory trick, sodium swells.
Lastly, you want to monitor your patient's daily weights. Remember to use the same time, same scale, and same clothes. Make sure to report an acute weight gain of two to three pounds, which could indicate worsening heart failure or proper diuretic dosage. You want to monitor intake and output and potassium levels. Let's review which diuretics are potassium sparing and which ones are potassium wasting.
Our potassium wasting diuretics are lup and thiazide and our potassium sparing diuretics are spurnolactone. Remember, S think sparing. Alright, let's do a practice question.
The nurse is caring for a client with congestive heart failure and is about to administer their morning dose of spironolactone, aldactone. Which of the following lab values should be reported before giving the scheduled medication? Pause the screen and comment your answer.
Okay, calcium of 10 milligrams per deciliter. This is within normal limits. A normal calcium is 9 to 11. Sodium of 132 milliequivalents per liter.
A normal sodium is 135 to 145. This is slightly lower than normal, but this is an expected finding in patients with heart failure. Due to the high amounts of fluid in the body, sodium is diluted, causing hyponatremia and edema. Potassium level of 5.3 milliequivalents per liter.
The normal potassium level is 3 to 5. Therefore, the patient's potassium value is too high and should be reported before giving the scheduled medication. Remember, spironolactone, think sparing, aka hyperkalemia. But let's look at our next option to be sure. Chloride of 102 milliequivalents per liter.
This is within normal limits. A normal chloride level is 95 to 105, making our answer option number three. You can grab more NCLEX style questions in the complete NCLEX study notebook. It comes with practice questions in the book and also online as well.
It covers the most important NCLEX topics, signs and symptoms, diseases, and it also has a calendar for you to be able to schedule your study time when it comes to the NCLEX. You can find the link to this book in the description below. That's all for diuretics. If you want more information on the different types of antihypertensives, you can watch this video.
Happy studying, future nurses!