November 29, 2022

Potassium-sparing diuretics pharmacology review for nursing students in preparation for the NCLEX exam.

Hey everyone it’s sarah thread sterner sorry and today we’re going to talk about potassium sparing diuretics and as always whenever you get done watching this youtube video you can access the free quiz that will test you on this medication so let’s get started as we’ve been going over these medications in this pharmacology series we have been remembering

The word nurse because this allows us to remember those important concepts we need to know for exams about these medications so first we’re going to start with the name the name of the drug tells us how the medication works which lays the framework for understanding everything else so we’re dealing with potassium sparing diuretics well that name right off the

Bat tells us we’re dealing with a diuretic so we’re going to be someway altering how this nephron is dealing with sodium and if we mess up how it’s dealing with sodium we can alter the way the body’s going to reabsorb water but this sigh retic is potassium sparing so it actually spares potassium compared to those other diuretics we talked about in this series

Like loop diuretics and thiazide they wasted potassium so this one’s actually going to spare it so let’s talk about how it does that well potassium sparing diuretics work to inhibit the sodium and potassium exchange that’s occurring within these cells that make up the distal parts of the nephron and we’re specifically talking about the late parts of the distal

Tubule and the collecting duct and what it’s going to do these medications is it’s going to affect the sodium channels so to help us understand how these medications are affecting the sodium channels let’s talk about our nephron so if we’re dealing with any type of diuretic it’s a really really high probability that these diuretics are going to somehow affect some

Structure within this nephron like with loop diuretics they affected loop of henle with the thiazide it affected the early part of the distal convoluted tubule so our nephron just to recap there’s millions of these little structures within your kidneys and they’re like the functional unit of the kidney because they help our kidney and produce urine so it starts up

In here in the glomerulus it’s going to filter your blood as blood is receive and it’s going to in a sense drip down what it filters down into bowman’s capsule and it’s gonna start going through the parts of the nephron and each part of this nephron you can see them in different colors we have the proximal convoluted tubule the live of henle the distal convoluted

Tubule and then the collecting duct each part is really assigned its own role for tweaking that filtrate so what’s going to happen to the filtrate hence what will eventually become urine is that it’s either going to take ions and water and put it back into the blood that’s what we call reabsorption or the blood is going to secrete things it doesn’t really need

Into the filtrate so it can be excreted that’s like secretion or and then eventually it’s just going to leave the body and be excreted as urine so in a sense you’re nephrons like maintaining homeostasis of your fluid electrolytes water and waste in the blood so how the tascam sparing diuretics work is they alter those sodium channels that make up that late part of

The nephron specifically that late distal tubule and the collecting duct and what they’re gonna do is they’re gonna alter how sodium is actually going to be reabsorbed out of that filtrate to go back into the blood and remember if we’re keeping more sodium in this filtrate within that nephron which is eventually going to become urine we’re gonna keep more water

With it and that will provide that diuretic effect so to help us understand that a little bit better and to be able to visualize it let’s look at that process of what’s happening with how like those ions actually cross over from the filtrate to go into the blood because that’s the process that these drugs are manipulating so here we have an illustration and this

Middle area represented in pink represents like the cells that make up the distal tubule and the collecting duct and within these cells you have to have these channels in these pumps to facilitate the movement of these ions so they can cross back and forth over here represented in red this red area this is our inner stitch um slash blood and it has you know ions

And other substances hanging out in it and some of those sentences want to get over here to the filtrate and over here in the orange that is represented with our lumen the inside of that nephron /the filtrate and again it also has ions in it don’t want to get over there to the blood so to do that has to use those channels and pumps one thing we want to concentrate

On is this sodium channel so the sodium channel just like its name says allow sodium to leave the filtrate and go into the cell but once it’s there it needs to get into the blood stream so in order to do that a sodium potassium pump will help it do that so what that this does is it takes the sodium pumps it over there into the blood but it has to exchange something

For that sodium it just put in there it has to take potassium and hydrogen ions and move it in the opposite direction and it will go this way and this is occurring to allow that to happen so we have sodium channels and potassium sodium pumps however whenever we throw on a potassium sparing diuretic it’s going to stop this channel that sodium channel from doing

That so you’re not gonna have sodium leaving this filtrate going in over here so more staying in the filtrate means more water is gonna stay in the filtrate we get that diuretic effect however it’s going to alter how this sodium potassium pump works it doesn’t have very much or at all any sodium to pump over into the blood so because it’s not going to do that

It’s not going to have the exchange of the potassium leaving the blood along with those hydrogen ions and going into the filtrate so you’re going to keep more potassium in the blood hence its potassium sparing so one thing i want you to remember with potassium sparing diuretics is that there when the directs that keep potassium through that process but patients

Can have hyperkalemia where their blood level of potassium is increase so remember that now there are two different types of potassium sparing diuretics they will all work together to achieve these same results but they will do it in different ways with what they influence so the first time i want to talk about are called epithelial sodium channel inhibitors these

Drugs directly inhibit this sodium channel so by doing that it’s going to cause more sodium to stay in the filtrate which will draw more water and we’ll have that diuretic effect but it’ll spare the potassium because we didn’t have that exchange with sodium and potassium via that pump so there’s that risk of hyperkalemia and some drugs that fall into this category

Of potassium sparing diuretics are triamterene and a miller id and the second group of potassium sparing diuretics are called aldosterone antagonists sometimes called aldosterone receptor blockers and just as their name says is that they antagonize aldosterone so they’re gonna work against the effects that aldosterone would try to create in your body now what does

Aldosterone do normally aldosterone causes your body to want to keep and reabsorb the sodium and the water so it’ll tell that nephron hey i need you to reabsorb sodium and water in exchange for wasting potassium and hydrogen ions and one way why your body would want to do that is to help with blood pressure management the blood pressure falls to low aldosterone can

Help increase blood volume to help increase blood pressure but how these drugs work is they tell aldosterone no you’re not going to do this because our dosterone influences the number of these sodium channels and these sodium potassium pumps so if we’re limiting their number we’re going to be limiting how this whole process is taking place so they have this same

Effect like these direct epithelial sodium channel inhibitors did with their diuretic effects they’re just doing it under the influence of aldosterone and these drugs include spironolactone and appler anon now let’s talk about what these medications are used for what do they treat well because potassium sparing diuretics alter how we reabsorb sodium in water they

Can be really beneficial in treating high blood pressure hypertension they can also help patients who have excessive fluid volume where they’re having edema and swelling related to like heart failure liver impairment or maybe neph rhotic syndrome they can also treat hypokalemia where you have a low potassium level in the blood due to a side effect that’s related to

Maybe the patients on a loop diuretic or thiazide so they may pick them on a potassium sparing diuretic to help prevent that and they can be used to treat hyperaldosteronism specifically the medications that antagonize aldosterone and medication that’s most commonly prescribed for this is spironolactone and with hyperaldosteronism the adrenal glands are producing

Too much i’ll dosterone and if we do that what’s going to happen we’re going to be keeping lots of sodium and water in our blood but we’re gonna be wasting lots of potassium so the patient can have high blood pressure and hypokalemia so we throw on this aldosterone antagonist this is going to help make it where we’re not keeping so much sodium and water so we can

Lower the blood pressure and we won’t be wasting so much potassium so we can keep our potassium levels stable now one thing i want to point out about potassium sparing diuretics is that they tend to be the weakest in there diuretic affects compared to the other drugs that are diuretics like loop diuretics and thigh azides because they don’t have such a profound

Effect on how we’re dealing with decreasing sodium reabsorption like with loop diuretics those are very powerful because they’re dealing with a part of the nephron that really plays a huge role in reabsorbing loss of sodium this isn’t really the case with potassium sparing diuretics which is why a lot of times potassium sparing diuretics will be combined with

Either like a loop diuretic or a thiazide now let’s wrap up this lecture and let’s talk about the nurse’s role the side effects and education pieces for the patient who may be taking a potassium sparing diuretic so we have learned that these medications are going to increase urination because they’re altering how we’re reabsorbing sodium which hence affects how

We’re going to deal with water so because they’re going to be urinating out more fluid they’re at risk for dehydration so as a nurse we have to watch out for that how can we tell our patient is dehydrated well we can look at their vital signs house their blood pressure if their systolic is less than 90 that tells us that we’ve depleted their fluid volume a little

Bit too much or how’s their heart rate is it increased where the body is trying to compensate for that low blood pressure anything greater than 100 their attack of kartik how’s your patient acting are they really thirsty or they fatigued they have mental status changes this could indicate that they are dehydrated because of those signs and symptoms and you want

To teach the patient how to identify that that’s happening to them at home and to report that to their physician also we want to monitor their intake in their output we want to make sure that they’re not putting out so much fluid compared to how much they’re taking in because we don’t want to dehydrate them plus we want to look at their renal function that’d be

You in and creatinine that tells us how well our kidneys are really working to filter our blood and if we dehydrate them too much we can cause some renal issues and potassium sparing diuretics are not for patients who have renal failure another they were watching out for our electrolyte imbalances and what was the big electrolyte imbalance i told you to watch

Out for is hyperkalemia because these medications spare potassium so a normal potassium level that you definitely want to put in your memory is three point five two five millionths per leader so anything greater than five we’re getting in hyper kaleem ‘ya territory so what are some signs and symptoms that your patient’s potassium level may be high without really

Even looking at the lab result well you want to make sure you’re looking at their ekg how do their tea waves look if they’re tall and peaked that could be an indication that they’re in hyperkalemia remember that that’s a big test question that they’d like to ask about fluid in electrolytes also how’s your patient reacting are they reporting muscle cramps muscle

Weakness are they having difficulty breathing or do they have paresthesia where their skin feels like it’s tingling and burning they’re nauseous or vomiting also teach the patient to recognize these signs and symptoms as well of course they can’t recognize the tall peaked t-waves because i don’t have an ekg monitor at home but teach them these other things also

You want to teach your patient to avoid foods high in potassium because we’re already keeping potassium we don’t want them to just go and eat lots of food rich in potassium so to help you remember foods that are high in potassium remember the word potassium and this includes foods like potatoes and pork oranges tomatoes avocados strawberries spinach fish mushrooms

And musk melons like cantaloupe in addition you want to tell your patient to avoid those salt substitutes because those actually contain potassium and many patients who are taking potassium sparing diuretics may be taking it for a heart condition like heart failure or high blood pressure and they’ve been educated watch your salt watch your salt so they may use a

Salt substitute not knowing that it’s really high in potassium so educate them about that as well now some medication interactions that you definitely want to watch out for again like i said patients who are taking potassium sparing diuretics may have heart failure so they may need to be taking an ace inhibitor an arb and those medications can increase potassium

As well we talked in depth for why that was if you want to check out those videos so you want to be watching that looking at the potassium level looking for those signs and symptoms hey the potassium level may be high also nsaids can cause that as well they’re taking something for pain that can increase potassium levels and lastly another thing is about drug wise is

Em because we’re altering how the nephron is working and reabsorbing and excreting and everything we can alter how the body can actually clear lithium where it could actually build up in the system so the patient’s lithium levels would need to be monitored closely because they’re at risk for lithium toxicity in a normal lithium drug level that you want to remember is

0.5 to 1.2 millimoles per liter so anything greater than that there is a risk of lithium toxicity and some miscellaneous side effects that you want to remember as a nurse so you can teach your patient is that some of these medications can upset the stomach so they may want to take this medication with food or right after they have a meal to help decrease those signs

And symptoms and these medications can produce an anti-androgen effect and we’re mainly talking about those aldosterone antagonists specifically spironolactone because this medication affects the androgen and progesterone receptors so some patients may experience gynecomastia minstrel problems and sexual dysfunction okay so that wraps up this review over potassium sparing diuretics

Transcribed from video
Potassium-Sparing Diuretics Pharmacology Nursing (Mechanism of Action) Review By RegisteredNurseRN