Pharmacology, part 3: Respiratory Medications - Corticosteroids, Leukotriene Antagonists, Antitussives

by Cathy Parkes

In this article, we cover some important respiratory medications including corticosteroids, leukotriene receptor antagonists, as well as antitussives.

This video follows along with our Pharmacology Flashcards.

Corticosteroids

What are corticosteroids?

Corticosteroids are a class of drug that lowers inflammation in the body and reduces immune system activity. We’ll focus on locally-acting steroids for the respiratory system here, including inhalers and intranasal corticosteroids. There are a number of medications that fall within this drug class and include beclomethasone (QVAR), mometasone (Asmanex), budesonide (Pulmicort), and fluticasone (Flovent).

Indications

Localized corticosteroids can be used year-round to treat asthma and rhinitis (runny nose).

Mode of action

Corticosteroids decrease inflammation locally by acting on cells that are responsible for inflammatory response.

Corticosteroids side effects

Side effects are much less than if taking a systemic steroid but can include headache, pharyngitis (sore throat), and a possible fungal infection from candidiasis.

Patient teaching for corticosteroids

An important teaching you’ll need to discuss with your patient is that after administration, they need to rinse their mouth out to decrease the risk of contracting a possible fungal infection from candidiasis (a type of yeast infection, also called thrush).

Corticosteroids are often used alongside bronchodilators for asthma. If your patient is going to be using a bronchodilator like albuterol, in conjunction with a corticosteroid, they should administer the bronchodilator first to help open up the airways, wait five minutes, and then administer the corticosteroid.

Cool Chicken If you take fluticasone for your nasal congestion, it will let you be able to play the flute.

(Playing the flute while you're congested would probably not work out, and that's why you need the fluticasone.)

Leukotriene receptor antagonists

Indications

Leukotriene receptor antagonists are a class of drug used to treat asthma and the prevention of exercise-induced bronchoconstriction (which causes wheezing and shortness of breath). Two medications that fall under this class include montelukast and zafirlukast.

Mode of action

Leukotrienes are inflammatory chemicals released in response to an allergen. Leukotriene receptor antagonists work to decrease the effect of leukotrienes in the body, which in turn reduces airway inflammation and bronchoconstriction.

Cool Chicken Meds that end in -lukast decrease the effect of leukocytes.

Side effects

The key side effect that you will see with leukotriene receptor antagonists is headaches. With zafirlukast, you may also see an increase in liver enzymes.

Administration

One important thing to remember about montelukast and zafirlukast is that they are oral medications, not inhaled or intranasal like many other respiratory drugs. A patient should take montelukast in the evening or two hours before exercise. Zafirlukast should be taken on an empty stomach.

Antitussive Medications

Antitussive medications are used to treat a patient's cough. If you break down antitussive you get anti- and then -tussive, which comes from tussis meaning cough. Specifically, these medications should be used for a dry cough only. A patient who has a productive cough (i.e., producing phlegm), should not be given an antitussive. We want patients to cough up the gunk, rather than allow it to sit in their lungs.

There are three main antitussives you should be familiar with for your pharmacology exam and the NCLEX.

Cool Chicken Remember A, B, C, D = Antitussives include benzonatate, codeine, and dextromethorphan.

Benzonatate

Mode of action

Benzonatate works by having an anesthetic (numbing) effect on the vagal nerve receptors in the airway. This relaxes the receptors so they are not as quick to create a cough as a reflex.

Side effects

Benzonatate side effects include sedation, constipation, as well as GI upset.

Codeine

Mode of action

Codeine works by binding to opioid receptors in the central nervous system, and reducing activity in the area of the brain that triggers coughing, so coughs are suppressed.

Side effects

Codeine is an opioid medication so it’s going to have some serious side effects. They include sedation, respiratory depression, hypotension, constipation, and GI upset.

Dextromethorphan

Mode of action

Dextromethorphan, often known by its brand name Delsym, works by suppressing the cough reflex in the medulla. Both codeine and dextromethorphan work centrally (meaning acting on the brain) rather than locally (acting on the throat).

Side effects

The side effects usually seen with dextromethorphan are fairly minor and may include dizziness and possible sedation at high doses.

The Pharmacology Video Series is intended to help RN and PN nursing students study for nursing school exams, including the ATI, HESI and NCLEX.


Full Transcript

In this video, we are going to go over some more important respiratory medications, including corticosteroids, leukotriene receptor antagonists, as well as antitussives.

So let's first talk about corticosteroids.

So we're going to focus on locally-acting steroids as opposed to systemic steroids, which we'll be covering in the endocrine system. So we're talking about either inhalers or intranasal corticosteroids. There's a number of medications that fall within this drug class. They are listed here on card number four [in the Pharmacology Flashcards] and include medications such as beclomethasone, mometasone, budesonide, and fluticasone.

So you would use these medications for asthma or rhinitis, which is a fancy name for a runny nose.

They work by decreasing inflammation locally.

And they do have some side effects. These side effects are much less than if we were taking a systemic steroid, but they can include things like a headache, pharyngitis, which is a fancy name for a sore throat, and a possible fungal infection from candidiasis.

So an important, super important teaching you need to do for your patient is after administration, they need to rinse their mouth out to prevent this fungal infection from occurring.

And then if your patient is going to be using a bronchodilator, such as albuterol, in conjunction with a steroid, they should administer the bronchodilator first to help open up the airways, wait five minutes, and then administer the corticosteroid.

So the one tip I have here is for the medication fluticasone. So if you take fluticasone for your nasal congestion, your rhinitis, it will let you be able to play the flute. Because playing the flute while you're congested would probably not work out, and that's why you need the fluticasone.

Now, let's talk about leukotriene receptor antagonists. The two medications I'd be familiar with that fall under this class include montelukast and zafirlukast. They both end in that -lukast.

They are used for asthma, and they are also used for prevention of exercise-induced bronchoconstriction.

So their mode of action is to decrease the effect of leukotrienes in the body which are inflammatory chemicals that are released in response to an allergen. So it decreases the effect of these leukotrienes which, in turn, reduces airway inflammation and bronchoconstriction.

The way that I remember this mode of action is that meds that end in -lukast help to decrease the effect of leukotrienes. Okay, which are those inflammatory chemicals.

Side effects that are associated with this class of medication include headache. And with zafirlukast, you may also see an increase in liver enzymes.

In terms of administration, montelukast should be taken in the evening or 2 hours before exercise. And zafirlukast is recommended to be taken on an empty stomach.

Now, let's talk about antitussive medications which are medications used to treat your patient's cough. There are a number to be familiar with. And if you're following along with cards, I'm on card number 6 [in the Pharmacology Flashcards].

So to remember which medications are antitussive, I remember A, B, C, D. So antitussives, which starts with A, include benzonatate, which starts with a B. Codeine, which starts with a C, and dextromethorphan, which starts with a D.

They're all used to treat cough, but they all work a little differently.

Benzonatate works by having an anesthetic effect on the vagal nerve receptors in the airway.

Side effects can include sedation, constipation, as well as GI upset.

Codeine binds to opioid receptors in the CNS and decreases the patient's cough reflex.

But as you know, Codeine is an opioid medication. So it's going to have some fairly serious side effects including sedation, respiratory depression, hypotension, constipation, and GI upset.

And then finally, we have dextromethorphan which you guys might know as Delsym. That's the brand name. It works by suppressing the cough reflex in the medulla.

So side effects that you may have with Delsym are usually pretty minor. They may include dizziness and possible sedation at high doses.

In my next video, I will be finishing up the key respiratory medications I feel that you should know. I'll be talking about expectorants, mucolytics, decongestants, as well as antihistamines. Thanks so much for watching!


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