Congestive Heart Failure & Myocardial Infarction Drugs

Are you having a hard time differentiating congestive heart failure (CHF) drugs from myocardial infarction (MI) drugs? In this lecture, you will learn how to appropriately identify which medication is given to CHF clients and which is given to MI clients.

So the main question is: What is the difference between CHF and MI drugs?

To answer that question, one must first know what’s going on between the two conditions.

Pathophysiology: Congestive Heart Failure

One of the major differences between congestive heart failure and myocardial infarction is where the complication originated. For CHF, it’s due to the ventricles inside the heart that are primarily responsible for pumping blood throughout the different parts of the body, delivering oxygen where it’s needed.

If there’s increased volume being pushed down into the ventricles, the heart tends to give up, leading to congestive heart failure. Furthermore, if there is increased vascular resistance within the vascular beds, the ventricles get exhausted and can either give up or become hypertrophic. Hypertrophy is due to swelling caused by compensation done by the ventricles.

Decreasing the Volume

To take the volume off the heart, diuretics are given. The different types of diuretics are:

  1. Loop
  2. Thiazide
  3. Potassium-sparing
  4. Osmotic

While these diuretics somehow differ in how they react, they do have the same goal – to get the load off of the ventricles.

Loop and Thiazide

Loop diuretics act on the descending loop of Henle, which means that this medication is responsible for triggering the excretion of fluid within the glomeruli.

Loop diuretics and thiazides are potassium-wasting diuretics. This information is vital especially during examinations wherein questions regarding potassium would usually come up.

Digoxin Toxicity

Clients taking potassium-wasting diuretics and who are taking digoxin at the same time, are at risk for digoxin toxicity. Digoxin is a cardiac glycoside that helps in depolarizing, for cases like atrial fibrillation. Therefore, giving potassium-wasting diuretics to clients who have a depleting potassium level will resort to toxicity because as the potassium goes down, the digoxin level will go up.

Remember, anything greater than 2.0 ng/mL, is considered as digoxin toxicity. One of the best indicators for digoxin toxicity is if the client starts seeing halos.

NCLEX® Trick Question

A tricky NCLEX® question when it comes to digoxin toxicity is:

If your client’s digoxin level reaches 1.9 ng/mL, would you give or hold the administration of digoxin?

Answer: Yes, because that is still within digoxin’s therapeutic level.

Potassium-Sparing Diuretics

Spironolactone is a popular potassium-sparing diuretic that blocks aldosterone in the kidneys while keeping potassium inside the body. Aldosterone or Aldos-“Tyrone” can be considered as the bouncer that is responsible for the regulation of the renin-angiotensin-aldosterone system (RAAS).

A good nursing question for potassium-sparing diuretics would be:

A client is going to be placed on a potassium-sparing diuretic, what should be the nurse’s client teaching?

Answer: Tell the client to eat a normal, healthy diet but should avoid potassium-rich foods like spinach, bananas, and green leafy vegetables.

Osmotic Diuretics

Mannitol is the popularly known osmotic diuretic that is usually given to a client with increased intracranial pressure. Osmotic diuretics help in withdrawing all excess extracellular fluid from the brain down to the potty.

On our next discussion, we will tackle further about myocardial infarction and its medications.

Quick Overview of Heart Failure Pharmacology

Posted on |

We’ll be having a quick congestive heart failure review and we’ll also go over the drugs involved in treating the condition.

Antihypertensive drugs are responsible for relieving pressure that’s being set on the heart. The aim is to basically get the heart pumping normally that it can stretch and squeeze to eject and distribute blood to different parts of the body with as little effort as possible.

Congestive Heart Failure

In congestive heart failure (CHF), there is a lot of pressure from the peripheral veins that is being pushed on the heart. A primary cause of CHF would be increased sodium in the diet. Fortunately, there are tons of medications that can take this pressure off of the heart and promote proper blood flow.

What are the drugs that help in alleviating the pressure from the heart? These drugs are categorized into A-B-C-D. What does each letter stand for?

The Drugs for Heart Failure

A is for ACE Inhibitors

ACE inhibitors act on the renin-angiotensin-aldosterone system (RAAS) in the kidneys, which are responsible for bringing the pressure from the peripheral veins and blood vessels to decrease the pressure experienced by the heart.

B is for Beta-blockers

The basic function of beta-blockers is to block the beta receptors that have sympathetic nervous system response. And since the response is sympathomimetic, it’s basically the fight or flight reaction of the body which causes increased blood pressure and heart rate.

Blocking the beta receptors will result in relaxation of the heart, resulting to decreased blood pressure and heart rate.

C is for Calcium Channel Blockers

At SimpleNursing.com, there is a separate video about calcium channel blockers showing a detailed instruction on how calcium affects your body and, specifically, your heart.

So, when you think of calcium, the first thing that would come to mind is, it’s mainly found in the bones and is required for hardening the bone structure. That said, if there is an overload of calcium, the heart will be directly affected, causing it to harden. And if that happens, it will be very difficult for the heart to stretch and squeeze blood to the different parts of the body. Therefore, calcium channel blockers block the channels responsible for heart calcification, bringing back the normal function of the heart.  

D is for Diuretics

You can think of diuretics as the agents that open up the faucet inside your body – the faucet being your kidneys. And because the urinary tract primarily functions to excrete fluid from the body, it is imperative that the kidneys are properly working to relieve the heart of unnecessary pressure due to fluid overload.

Diuretics are effective in opening up these faucets (kidneys) to release toxins and fluids out of the body. Some of the main examples of diuretics are Lasix and hydrochlorothiazide. By decreasing the amount of blood or fluid that is going inside the heart, diuretics reduce stress and workload of the heart. Diuretics are basically calming down the increased pressure being pushed on the heart to the point of normalcy.

On our next discussion, we’ll take an in-depth look at the mechanism of action of ACE inhibitors, beta-blockers, calcium channel blockers, and diuretics.

You can drop by SimpleNursing.com and gain access to tons of topics that will help you pass major nursing exams and your NCLEX®. See you there!