Pharmacology, part 16: Cardiovascular Medications - Electrolyte & Acid/Base Imbalances
November 06, 2020 Updated: December 29, 2021 9 min read 2 Comments
In this article, we cover medications and supplements that are used to treat and prevent electrolyte imbalances and acid-base imbalances in the body. The Nursing Pharmacology video series follows along with our Pharmacology Flashcards, which are intended to help RN and PN nursing students study for nursing school exams, including the ATI, HESI, and NCLEX.
When you see this Cool Chicken, that indicates one of Cathy's silly mnemonics to help you remember. The Cool Chicken hints in these articles are just a taste of what's available across our Level Up RN Flashcards for nursing students!
Calcium - calcium carbonate (Caltrate, Mylanta, Rolaids, Tums), calcium citrate (Citracal), calcium gluconate (Kalcinate)
Calcium is a mineral that is necessary for life and is essential for building bones and keeping them healthy. Calcium also enables our blood to clot, our muscles to contract and our heart to beat. About 99% of the calcium in our bodies can be found in our bones and teeth. Calcium given as a supplement or medication can be used to treat and prevent osteoporosis (weak bones), hypocalcemia, hyperkalemia, hypermagnesemia, and as an antacid to relieve heartburn, acid indigestion and upset stomach.
Calcium carbonate (Caltrate, Mylanta, Rolaids, Tums) and calcium citrate (Citracal) are used as a treatment for hypocalcemia (low levels of calcium in the blood) and also help to prevent postmenopausal osteoporosis. Calcium carbonate is also used as an antacid that helps relieve heartburn, acid indigestion and upset stomach.
Calcium gluconate (Kalcinate) can be used as an emergency treatment for hyperkalemia (high potassium in blood) and hypermagnesemia (high magnesium in blood). If a patient’s potassium or magnesium levels are too high, calcium gluconate is the antidote.
In terms of side effects, if a patient has too much calcium, it can cause constipation as well as dysrhythmias such as bradycardia.
Expected range of calcium
The expected range of calcium in the bloodstream is between 9 and 10.5 mg/dl. In order to absorb calcium, patients need sufficient levels of vitamin D. To learn more about this lab value and many others, check out our lab value flashcards for nursing students.
Potassium chloride is used to prevent or to treat low blood levels of potassium (hypokalemia). Potassium is an important electrolyte needed to maintain intracellular fluid volume and helps your cells, kidneys, heart, muscles and nerves work properly. Potassium levels can be low as a result of a disease (like hyperaldosteronism) or from taking certain medicines, or after a prolonged illness with diarrhea or vomiting.
Potassium chloride can be administered orally or through the IV route. When taking potassium chloride orally, the pills are very large and can be hard for patients to swallow. It’s also available in powder form that can be taken with water and can taste bad.
When given through the IV route, it can cause burning at the IV site, however patients can request that it be mixed with lidocaine so that it does not burn as much.
The key side effects to be aware of with potassium chloride are dysrhythmias. If levels are too low or too high it could lead to fatal heart arrhythmias.
Normal range for potassium
The normal range for potassium is between 3.5 and 5 mEq/L. To learn more about this lab value and many others, check out our lab value flashcards for nursing students.
Sodium bicarbonate is an alkalinizing agent that can be used for metabolic acidosis, which develops when too much acid is produced in the body. It can also be used as a treatment for peptic ulcer disease, a condition in which painful sores or ulcers develop in the lining of the stomach or the first part of the small intestine (the duodenum). It can also be given in a code blue situation when a patient has cardiac arrest and resulting acidosis.
Mode of action
Sodium bicarbonate is a salt that breaks down to form sodium and bicarbonate in the body. This breakdown makes a solution alkaline, meaning it is able to neutralize acid and promote a healthy PH balance.
In terms of side effects, if a patient is given too much sodium bicarbonate, they can develop metabolic alkalosis, which is a condition that occurs when your blood becomes overly alkaline (opposite of acidic).
To learn more about metabolic acidosis vs. alkalosis, check out our Arterial Blood Gas Flashcards for nursing students.
When caring for a patient taking sodium bicarbonate, it’s important to monitor their arterial blood gas (ABG) levels and bicarbonate levels, which should be between 22 and 26 mEq/L.
To learn more about arterial blood gas (ABG), check out our arterial blood gas interpretation flashcards for nursing students.
Sodium polystyrene sulfonate (Kayexalate)
Sodium polystyrene sulfonate (Kayexalate) is used to treat a high level of potassium in your blood, also called hyperkalemia. Too much potassium in your blood can sometimes cause heart rhythm problems.
Mode of action
Sodium polystyrene sulfonate works by exchanging sodium ions for potassium ions in the intestine, which helps to increase excretion of potassium in the body.
Side effects with sodium polystyrene sulfonate can include constipation or diarrhea, fecal impaction, nausea, vomiting and hypokalemia. Anytime a patient has hyperkalemia (high potassium levels) or hypokalemia (low potassium levels) they are at risk for arrhythmias.
To learn more about this lab value and many others, check out our lab value flashcards for nursing students.
When caring for a patient on sodium polystyrene sulfonate, it’s important to monitor their stools during therapy for constipation and possible fecal impaction. It may be necessary to give the patient a laxative concurrently with Kayexalate during therapy.
Magnesium supplements (magnesium chloride, magnesium oxide, magnesium gluconate)
Magnesium is an important electrolyte needed for nerve and muscle function, bone formation, and is also critical for many biochemical reactions in the body. It can be used to treat hypomagnesemia, a condition in which magnesium levels in the blood are lower than normal. Magnesium can also be used to treat a dysrhythmia called torsades de pointes, which is covered in our EKG interpretation video series. Lastly, magnesium can be used to treat preterm labor because it helps to slow uterine contractions.
A key and common side effect with magnesium supplements is diarrhea. Magnesium toxicity is also an important side effect to be aware of when a patient is taking magnesium supplements and the signs and symptoms are very important to know when taking the NCLEX and nursing exams.
Signs and symptoms
Signs and symptoms of magnesium toxicity include decreased tendon reflexes, urine output that falls below 30 ml an hour, respiratory depression, cardiac depression and hypotension.
Too much magnesium brought Maggie to her knees (due to cardiac and respiratory depression).
Calcium gluconate, which we covered above, can be used to treat magnesium toxicity.
When caring for a patient taking magnesium chloride, it’s very important to monitor the patient’s magnesium levels as well as the patient’s stools due to the common side effect of diarrhea.
Normal range of magnesium
The normal range of magnesium should be between 1.3 and 2.1 mg/dL. If you’d like to learn more about these lab values and more, check out our lab value flashcards for nursing students.
Okay. In this video, we are going to talk about some medications that are used to correct electrolyte imbalances and acid-base imbalances in the body.
Let's first talk about calcium. So we have calcium carbonate, calcium citrate, and calcium gluconate.
So calcium carbonate and calcium citrate are used for hypocalcemia, and they are also used to help prevent post-menopausal osteoporosis.
Calcium gluconate can be used for emergency treatment of hyperkalemia and hypermagnesemia. So if our patient's potassium or magnesium levels are way too high, then calcium gluconate is going to be the antidote.
The mode of action -- calcium is an important mineral needed for bone and teeth formation as well as nerve and muscle function and clotting.
In terms of side effects, if we have too much calcium, that can cause constipation as well as dysrhythmias such as bradycardia.
So keep in mind the expected range of calcium in the bloodstream, which is between 9 and 10.5.
Also keep in mind that in order for your patient to absorb calcium, they need sufficient vitamin D as well.
Now let's talk potassium chloride, which is a potassium supplement used to treat high hypokalemia.
So potassium is a really important electrolyte needed to maintain intracellular fluid volume. It's also super important for nerve, muscle, and heart function.
We can give a potassium supplement through the oral route or the IV route. When you're giving it through the oral route, it comes in these huge horse pills. It's literally this big, which sometimes is an issue for patients to swallow.
You can also get it in this powder, which kind of turns the water orange, and per my patients, tastes really disgusting.
Or you can give it through the IV route, which can cause some burning at the IV site. So you can request that your doctor write an order that it be mixed with lidocaine so that doesn't burn so much when you're giving it through the IV route.
So in terms of side effects, arrhythmias is going to be the really important one to remember here. So with potassium levels, if your potassium levels are too high or too low, the thing you need to worry about for your patient is dysrhythmias. So we need to make sure their potassium levels stay in the right zone because whether they go up too high or too low, then we could have fatal heart arrhythmias.
The normal range for potassium is between 3.5 and 5.
Let's talk about sodium bicarbonate, which is an alkalinizing agent that can be used for metabolic acidosis as well as peptic ulcer disease.
I also have seen it used many times in a code blue situation when a patient has cardiac arrest and resulting acidosis.
So it works by promoting an acid-base balance in the body by releasing bicarbonate ions.
In terms of side effects, if we give too much of this, then we can end up with metabolic alkalosis.
So during therapy, we're definitely going to want to monitor the patient's ABGs and make sure their bicarbonate level is somewhere between 22 and 26.
Now let's talk about sodium polystyrene sulfonate, which is Kayexalate. And that is exactly how I'm going to refer to it for the rest of this little segment of video just because the sodium polystyrene sulfonate is a mouthful, and I can't tell you how many times I've cut this video.
So Kayexalate is a hypokalemic agent, so it's used to help bring down potassium levels when we have hyperkalemia.
It works by exchanging sodium ions for potassium ions in the intestine, which helps to increase excretion of potassium from the body.
So side effects can include constipation, fecal impaction, nausea and vomiting, and possible hypokalemia. Right? If we bring down those potassium levels too far, we can end up with a different problem, with hypokalemia. And remember, anytime we have hyperkalemia or hypokalemia, the patient is at risk for arrhythmias.
So the expected range for potassium is between 3.5 and 5.
And you definitely want to monitor your patients' stools during therapy for constipation and possible fecal impaction. And it may be necessary to give them a laxative concurrently with Kayexalate during therapy.
Finally, let's talk about magnesium supplements, which can include magnesium chloride, magnesium oxide, and magnesium gluconate.
So we would use these supplements to treat hypomagnesemia. We can also use magnesium to treat a dysrhythmia called torsades de pointes, which I talk more about in my EKG video series.
Magnesium can also be used to treat pre-term labor because it helps to slow uterine contractions.
So magnesium is an important electrolyte needed for nerve and muscle function as well as bone formation. It is also critical for many biochemical reactions in the body.
So the key side effect with magnesium supplements is going to be diarrhea. Very common.
But in addition, we need to be on the lookout for magnesium toxicity, and knowing the signs and symptoms of magnesium toxicity is going to be really important for you to know for the NCLEX and for your nursing exams.
So these symptoms include decreased deep tendon reflexes, a urine output that falls below 30 ml an hour. Also respiratory depression is a sign of magnesium toxicity, as well as cardiac depression, including hypotension.
So the way I remember these side effects is I remember that, "Too much magnesium brings Maggie to her knees," due to that respiratory depression and cardiac depression.
So keep in mind for magnesium toxicity, we can give calcium gluconate, which we talked about a little bit earlier, and then we're also going to want to keep an eye on your patient's magnesium levels. So those should be between 1.3 and 2.1.
And that, my friends, is the end of the cardiovascular section of our Pharmacology flashcards, edition 2.0. If you have found these videos helpful, be sure to like and comment on our videos, and share link with your classmates and friends in nursing school. So next up, we're going to be covering important medications that you need to know for the nervous system. Thanks so much for watching!
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