Chapter 38: Upper Respiratory Disorder Drug Therapy

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Welcome back to the Deep Dive.

If you are a regular listener, you know the drill.

We usually take this massive stack of articles, research papers, hot takes, and we boil them all down into something you can actually use.

But today is a little different.

Today's a little bit special.

We are shifting gears.

We certainly are.

Usually we're looking at the big messy picture of the world.

Today, we are zooming in with laser precision.

We are doing a last minute lecture edition.

I love that title.

It sounds so high stakes.

It kind of is, you know, especially for the people we're doing this for.

We're tackling a very specific, very dense text, Chapter 38 from Pharmacology, A Patient -Centered Nursing Process Approach, the 12th edition.

And the topic is upper respiratory disorders.

So if you're a nursing student out there sweating over an upcoming exam or, you know, maybe a working nurse who just realized they've forgotten exactly why we don't give certain cold meds to patients with high blood pressure, this one's for you.

This is your survival guide.

Exactly.

Our mission today is to take that chapter, which I have right here, and it is heavy and turn it into a conversation that actually sticks in your brain.

And we really need to be clear about the rules of engagement here.

We are sticking strictly to the text provided in this chapter.

I'm not going to bring in my own, you know, anecdotes about what I saw in the ER last week, and we aren't pulling in random studies from the internet.

We're giving you the facts exactly as the textbook presents them, because that is what's going to be on the test.

Right.

We're basically the audio version of highlighting the textbook, but we're going to help you understand what you're highlighting.

So before we get lost in the leads of molecules and receptors, give us the lay of the land.

What's the roadmap for Chapter 38?

So we're going to build this house from the foundation up.

We have to start with the physiology of the respiratory system.

You just can't understand the drugs if you don't understand the plumbing.

Makes sense.

Then we'll look at the actual problems, the common cold and rhinitis.

And then we get to the medicine cabinet.

Exactly.

The bulk of our time will be spent doing a really deep dive into the major drug classes.

Antihistamines, decongestants,

intranasal glucocorticoids.

Which is just a fancy way of saying nasal steroids, right?

It is, yeah.

Then we'll cover antipses and expectorants.

We will touch on some related disorders like sinusitis and pharyngitis.

And then probably the most important part.

The application.

We wrap it all up with the nerfing process.

How do you actually apply this clinical judgment to a real, living, breathing human being?

I'm ready.

Let's start with the plumbing.

Section 1.

Physiology.

Now most people just think lungs, but the text makes a pretty sharp distinction right out of the gate between the upper and lower respiratory tracts.

It does.

And that distinction is absolutely critical because

different infections and different drugs target different areas.

The upper respiratory tract is entry point.

We're talking about the nares, your nostrils, the nasal cavity, the pharynx, which is the throat, and the larynx, or the voice box.

Okay, so essentially everything in the head and neck area, more or less.

Roughly, yes.

And then you have the lower respiratory tract.

This is everything below the larynx.

You've got the trachea, the bronchi, the branch out, the smaller bronchioles, and finally the alveoli and the alveolar capillary membrane.

And that's where the magic happens, right?

In the alveoli.

That is where all the work gets done.

Air enters through the upper tract, it gets warmed and filtered, travels down to the lower tract, and lands in the alveoli for gas exchange.

Now you just mentioned gas exchange.

The text brings up two terms that I feel like everyone uses interchangeably in casual conversation.

Ventilation and respiration.

But in frontocology, they are not the same thing at all, are they?

Oh, not at all.

And mixing them up is a classic rookie mistake on an exam.

Okay, break it down for us.

Ventilation is purely mechanical.

It is simply the movement of air.

So imagine a bellows or a fan.

It's the process of moving air from the atmosphere through those upper and lower airways and getting it to the alveoli.

So if I'm just sitting here breathing in and out, I am ventilating.

Correct.

Inspiration is air in, expiration is air out.

That whole process is ventilation.

Respiration, however, is

physiological.

It's the chemical part.

Respiration is the actual process of gas exchange that happens at that alveolar capillary membrane.

So hypothetically, you could be ventilating, moving air in and out, but if that membrane is blocked or damaged for some reason, you aren't actually respirating.

Precisely.

You can have air movement without effective gas exchange.

In fact, the text breaks respiration down into three distinct phases to make this crystal clear.

Phase one is ventilation, just getting the oxygen through the airways.

Okay, so that's step one.

What is phase two?

Phase two is perfusion.

This refers to the blood flow.

You need blood flowing at that alveolar capillary bit to pick up the oxygen.

Right.

The delivery truck has to show up.

Exactly.

And the text makes a really, really important point here.

Perfusion must be matched by adequate ventilation.

Meaning the air has to actually reach the blood.

Yes.

If you have factors that decrease ventilation and the text lists things like mucosal edema, which is swelling or thick secretions or even bronchospasms, you are increasing the resistance to air flow.

So the road is blocked.

The road is blocked.

If the air can't get there, it doesn't matter how good the blood flow is, you aren't getting any gas exchange.

And the third phase.

The third phase is diffusion.

This is just the physics of it.

It's the movement of molecules from a higher concentration to a lower concentration.

Okay.

So oxygen diffuses from the alveoli into the capillaries because there's less oxygen in the blood.

And at the same time, carbon dioxide diffuses from the blood into the alveoli to be exhaled because the concentration is higher in the blood.

Ventilation, perfusion, diffusion.

It's like a chain reaction.

If any one of those links breaks, you're in trouble.

Exactly right.

And most of the drugs we're going to talk about today are designed to fix the ventilation part of that chain.

They're trying to clear the airway, reduce the swelling, dry up the secretions so that air can move freely again.

Which brings us directly to the enemy of clear airways, the common cold.

The text calls it the most prevalent type of upper respiratory infection, or URI.

It is absolutely ubiquitous.

The statistics in the chapter are actually kind of exhausting just to hear.

Adults average two to four colds per year.

That feels about right, unfortunately, but the number for kids is just wow.

It's significantly higher.

Children average four to 12 colds per year.

12 colds a year?

That is basically one a month.

If you're a parent listening to this right now, you are just nodding your head.

It explains a lot, doesn't it?

Why pediatric clinics are always full.

And there is a seasonality to it.

About 50 % of the population gets a winter cold and about 25 % get a summer cold.

Physiologically, what is actually attacking us?

It's the rhinovirus.

And it primarily affects the knees of pharyngeal tract.

And when it hits, it usually brings along its annoying friend,

acute rhinitis.

Okay, break that down for us.

What is acute rhinitis, technically?

Well, itis always means inflammation.

So acute rhinitis is simply the acute inflammation of the mucous membranes of the nose.

That's what gives you that miserable,

stuffy, swollen feeling.

But we have to be careful here because not all rhinitis from a cold, is it?

Right.

This is a key differential diagnosis for a nurse to understand.

We have acute rhinitis, which usually accompanies the common cold and is viral.

Then we have allergic rhinitis, which most people call hay fever.

So how do we tell them apart?

The symptoms feel so similar.

They can look really similar.

Both result in increased nasal secretions of runny nose.

But the cause is completely different.

Acute rhinitis is a virus.

Allergic rhinitis is caused by pollen or animal dander or other foreign substances that trigger an immune response.

I want to spend a minute on transmission because the text paints a very specific picture of how colds get around.

And it's not just people coughing in your face.

No.

And this is crucial for patient teaching.

A cold is most contagious one to four days before symptoms even start.

That's the incubation period.

That is just diabolical.

You are spreading the virus before you even know you're sick.

It's very effective.

And you stay contagious for the first three days of the symptoms.

And regarding how it spreads, we tend to worry about airborne droplets, which is valid.

But the text emphasizes that transmission occurs more frequently from touching contaminated surfaces and then touching your own nose or mouth.

So the doorknob, the shopping cart handle, the elevator button.

Exactly.

The virus hangs out there.

You touch it, maybe rub your nose an hour later.

And congratulations, you have a rhinovirus infection.

Hand hygiene.

It always, always comes back to hand hygiene.

It is the single most effective preventative measure.

But clearly we aren't perfect at it because the text notes that over $60 billion, that's with a B, is spent each year in the U .S.

on over -the -counter cold and cough preparations.

$60 billion.

That is a massive industry.

It is.

And honestly, a lot of that money is spent inefficiently.

People buy these multi -symptom relief products when they only have one symptom.

That's why we need to understand these drug classes.

We need to know what we are putting into our bodies and why.

Okay, let's do it.

Let's start with the heavy hitters.

Section three, antihistamines.

Or more technically,

H1 blockers.

Right.

So antihistamines are fascinating because they work by competition.

They don't kill the virus or get rid of the allergen.

They just block the body's reaction to it.

They are what we call H1 antagonists.

Meaning they antagonize the H1 receptor.

Exactly.

They compete with histamine for those receptor sites on the cells.

So it's like a game of musical chairs.

That's a great analogy.

If the drug molecule sits in the chair first, the histamine can't sit down and the allergic reaction doesn't happen or it's at least lessened.

But we have to distinguish between H1 and H2 receptors.

The text makes a big deal about this.

What is the difference?

So H1 stimulation is what we're worried about in the upper respiratory tract.

When H1 receptors are stimulated, the smooth muscles, like those lining your nasal cavity, constrict.

And that causes the congestion and secretions.

Okay.

So H1 is the nose and H2.

H2 stimulation increases gastric secretions.

It's related to stomach acid and peptic ulcers.

So if you are treating a cold or an allergy, you want an H1 blocker.

An H2 blocker would be something like fomotidine for your heart burn and it won't do a thing for your runny nose.

Okay.

So antihistamines block that H1 receptor.

What does that actually do for the patient?

What relief do they feel?

It decreases nasopharyngeal secretions.

It basically dries you up.

It also decreases nasal itching and that tickling sensation that makes you sneeze over and over.

However, the text drops a major warning flag right here about anaphylaxis.

This is a huge life safety point.

Students often think, oh, anaphylaxis is a severe allergy, so I should give an antihistamine.

The text says very clearly, anahistamines are not useful in an emergency situation like anaphylaxis.

Why not?

They block histamine, right?

They do, but they simply aren't potent enough and they don't work on the right systems.

They are absorbed rapidly, usually in about 15 minutes, but anaphylaxis is a massive systemic cascade.

Your blood pressure is dropping, your airway is closing.

You need epinephrine to reverse that.

Anahistamines are for the runny nose, not the closing throat.

That is a very good distinction.

Now let's talk about the generations.

We have first generation and second generation anahistamines.

This feels like the biggest decision point when you're standing in the pharmacy aisle.

It is.

It really is.

First generation anahistamines are the originals.

The prototype drug listed in the text is deucinhydramine.

Most people just know it as benadryl.

And what defines this first generation?

What are its characteristics?

They work well, but they are messy.

They cause significant drowsiness, dizziness, fatigue, and what we call anti -cholinergic symptoms.

We hear anti -cholinergic all the time in nursing school.

Let's really impact that.

What does an anti -cholinergic effect actually feel like to a patient?

There is a classic mnemonic we teach.

Can't see, can't pee, can't spit, can't...

Well, the last one is can't defecate.

Okay.

It basically dries everything out.

You get dry mouth, urinary retention, blurred vision, and constipation.

So diffinhydramine dries up your nose, but it also dries up everything else along with it.

Exactly.

Let's look at the prototype drug chart for diffinhydramine in the book.

Its uses are incredibly broad.

Allergic rhinitis, the common cold,

cough, sneezing, pruritus, which is itching, urticaria, which is hives.

And motion sickness.

Motion sickness.

And it's very, very commonly used as a sleep aid.

Because it just knocks you out.

It really does.

Drowsiness is listed as a major side effect.

The text explicitly warns, patients should not drive or operate dangerous machinery when taking first generation antihistamines.

It's a serious safety issue.

Let's talk about the pharmacodynamics.

How fast does it work?

How long does it last?

Orally, the onset is about 15 to 45 minutes.

If you give it IM,

intramuscularly, it's 20 to 30 minutes.

But if you give it IV intravenously, the onset is immediate.

And it lasts.

The duration is about four to six hours, which is why you have to re -dose it so often.

Who should not take diffinhydramine?

Let's talk about contraindications.

This goes right back to those anticholinergic effects.

It is contraindicated in acute asthma attacks.

But what I really want to highlight is narrow angle or closed angle glaucoma.

Why glaucoma?

What's the connection?

Because anticholinergic properties can increase intraocular pressure.

So if a patient already has this type of glaucoma, this drug could trigger a dangerous spike in pressure inside their eye.

And what about urinary retention?

Same logic.

If a patient already has trouble voiding, say, an older gentleman with an enlarged prostate, giving him a drug that causes urinary retention is just going to make his life miserable or even cause a medical emergency.

It's also contraindicated in severe liver disease because the liver has to metabolize it.

Talk to me about interactions.

What makes Benadryl dangerous when you mix it with other things?

The big one is CNS depression.

Since diffinhydramine itself causes drowsiness, which is a form of central nervous system depression, if you combine it with alcohol, narcotics, hypnotics, or barbiturates, you are doubling or even tripling down on that depression.

It can lead to severe sedation, even respiratory depression.

The text also lists some adverse reactions that go beyond just side effects.

These sound more serious.

They are.

These are rare but life -threatening blood disorders,

agranulocytosis, hemolytic anemia, and thrombocytopenia.

Essentially, a drug can actually cause your body to destroy its own blood cells.

It's very rare but very serious.

Before we move on, there is a patient safety alert box in the text regarding the name Benadryl.

Oh, this is a classic look -alike, sound -alike error.

Do not confuse Benadryl with Benazeparol.

They sound very similar when you say them fast.

They do.

But Benazeparol is an ACE inhibitor used for high blood pressure.

If you mix those up, you are treating an allergy with a heart medication or vice versa.

It's a potentially deadly error.

Always check the spelling.

Okay, that's first generation.

Sleepy, dry, and you have to be really careful with certain patients.

Now,

what about the second generation antihistamines?

So these were developed specifically to solve the sleepy problem.

They are often called non -sedating antihistamines.

They have far fewer anticholinergic effects and a much, much lower incidence of drowsiness.

How do they manage that?

Why are they less sedating?

The text doesn't go deep into the molecular biology, but essentially, they don't cross the blood -brain barrier to the same extent that diphenhydramine does.

So they work on the histamine receptors in the body without affecting the brain as much.

Who are the main players in this group?

Table 38 .1 in the chapter lists them out.

We have cetirizine, fexofenadine, loratadine, and deseratadine.

You're Zyrtec, Allegra, Claritin.

And there's a nasal spray in this category too, right?

Yes, a Xelestine.

It's an antihistamine, but it's delivered directly to the nose, which is great for minimizing systemic side effects.

One thing I noticed in the text is the huge difference in half -life between the generations.

It's a massive difference, and it's a huge quality of life factor.

First -gen drugs have shorter half -lives, like we said, four to six hours.

These second -gen drugs usually have half -lives ranging from three to thirty hours.

For example, loratadine has a half -life of three to twenty hours, and its metabolite, deseratadine, is twenty to thirty hours.

And what does that mean for the patient in practical terms?

Convenience.

It allows for once -daily dosing.

You take one little till in the morning, and you're good for twenty -four hours.

With Benadryl, you might be popping pills every four to six hours and, you know, falling asleep at your desk.

So if we were to summarize this for the students listening,

first -gen, like diffenhydramine, is cheap and effective, but makes you drowsy and dry.

Second -gen, like loratadine or satirazine, is less drowsy and lasts a lot longer.

That's the perfect takeaway.

Choose the right drug for the right patient and the right situation.

All right, moving on to section four, nasal and systemic decongestants.

I feel like this is where the public gets really confused.

They think antihistamine and decongestant are the same.

They definitely aren't.

They work in completely different ways.

Antihistamines block the chemical that causes the reaction.

Decongestants treat the result of the reaction, specifically the swelling.

So let's explain the physiology of a stuffed nose.

Why can't I breathe through my nose when I have a cold?

It's usually not just mucus that's blocking you up.

It's the blood vessels.

Congestion results from the dilation of nasal blood vessels.

When they dilate, they get bigger and they leak fluid into the surrounding tissue spaces.

That swelling physically blocks the nasal cavity.

So it's literally swollen shut.

How do you decongestants fix that?

They are sympathomimetic amines.

Sympathomimetic.

Okay, that means they mimic the sympathetic nervous system.

The fight -or -flight system, exactly.

They specifically stimulate the alpha -adrenergic receptors in the blood vessels of the nose.

And what happens when you stimulate an alpha receptor in a blood vessel?

Vasoconstriction.

The blood vessels clamp down and shrink.

When the vessels in the nose shrink,

the mucus membranes shrink and fluid secretion is reduced.

The airway physically opens up.

Okay, we have two main ways to deliver these drugs.

A nasal spray or a systemic pill.

What is the trade -off between the two?

Nasal sprays like oxymetazine or phenylephrine act very promptly.

They're super fast because you're putting the medicine right on the source of the problem.

And generally, they have fewer systemic side effects because the drug stays mostly in the nose.

And the systemic pills, the tablets.

Like pseudophadrine.

They relieve congestion for a longer period than the sprays do, but because the drug goes through your entire bloodstream, they cause more side effects throughout the body.

Let's stick with the nasal sprays for a second because there is a very, very strict rule in the text about them.

I call it the three -day rule.

This is probably the most frequent exam question on this topic, and it's something patients get wrong all the time.

Frequent use of nasal sprays or drops can result in something called rebound nasal congestion.

What exactly is rebound congestion?

It sounds awful.

It is awful.

Think of it as the body fighting back.

You keep artificially constricting those blood vessels with the spray.

Eventually, the tissue becomes irritated, and when the drug wears off, the vessels dilate even more than they were before.

So the patient feels stuffier, so they use more spray, and it creates this vicious cycle of dependency.

Oh, wow.

So the treatment becomes the problem.

What does the text say is the hard limit?

Limit use of nasal decongestant sprays to three days.

Period.

Full stop.

If you are still stuffy after three days, you need to stop the spray and switch strategies.

Now let's talk about the systemic decongestants and their side effects.

You said they are sympathomimetics.

They mimic fight or flight.

Right.

So just imagine what happens when you activate your fight or flight response.

You get jittery.

You get nervous.

You might feel restless, have trouble sleeping.

And what happens to your heart and your blood pressure?

It goes up.

These drugs cause vasoconstriction everywhere in your body, not just in your nose.

So your blood pressure increases, your heart rate can go up.

Which leads us directly to the contraindications.

Who absolutely needs to avoid these, or at least be very careful?

The text lists hypertension, cardiac disease, hyperthyroidism, and diabetes mellitus.

Anyone with high blood pressure or heart problems should be extremely cautious.

Okay.

Hypertension and cardiac disease make sense.

But why hyperthyroidism and diabetes?

Well, hyperthyroidism already puts you in a hypermetabolic state, kind of like a low -grade fight or flight all the time.

Adding a sympathomimetic on top of that can be dangerous.

And for diabetes, sympathetic stimulation can actually increase blood glucose levels.

So it can throw their blood sugar control off.

What about drug interactions?

The really scary one is MAOIs, monoamine oxidase inhibitors.

If you take a decongestant with an MAOI, you are risking a severe hypertensive crisis or cardiac dysrhythmias.

It's a very dangerous combination.

And the text also mentions caffeine.

Yeah, it says to avoid large amounts of caffeine.

It's just common sense, really.

If you take a jittery drug and wash it down with a triple espresso, you're going to have palpitations and feel terrible.

We have to address the elephant in the room with pseudoephedrine.

You can't just buy it off the shelf anymore.

It's behind the counter.

It is.

And for a very specific reason.

Pseudoephedrine is a highly effective decongestant.

But chemically, it is very similar to methamphetamine.

It can be used as a precursor ingredient to illegally manufacture meth.

So the government stepped in?

Yes.

With the Combat Methamphetamine Epidemic Act, it puts strict limits on sales.

You can only buy 3 .6 grams per day and a total of 9 grams within a 30 -day period.

And you can't just grab it and walk out?

No.

It's kept behind the pharmacy counter.

You have to show a government -issued ID.

And the pharmacy scans it into a national database to make sure you haven't bought your limit at the pharmacy down the street an hour ago.

It's a hassle, but it's the law.

Okay, let's move to Section 5.

Intranasal glucocorticoids.

That's a mouthful.

Let's just call them nasal steroids.

Sounds good.

These are drugs like beclomethazone, butynide, fluticasone, mimetazone, and tryamcinolone.

You're Flonase.

You're nasinex.

What is the strategy here?

Why are we using a steroid for a runny nose?

It's all about inflammation.

Steroids are incredibly powerful anti -inflammatories.

They're extremely effective for treating allergic rhinitis, because they shut down that whole inflammatory response, which then decreases the rhinorrhea, the runny nose, the sneezing, and the congestion.

But these are not for instant relief, are they?

This isn't like a decongestant spray.

No, absolutely not.

That's a key patient teaching point.

You don't take a puff of fluticasone and feel your nose open up in 30 seconds, like you do with oxymetazoline.

These are for maintenance therapy, often for seasonal allergies.

It can take a week or two to feel the full effect.

There is a very specific instruction on how to use the spray in the text.

I feel like most people, myself included, probably do this wrong.

They absolutely do.

And doing it wrong can lead to side effects, the text says.

Direct the spray away from the nasal septum.

Away from the middle part?

Why?

The septum, the cartilage in the middle of your nose, is covered by a very thin, sensitive mucous membrane.

If you blast it with steroids every single day, you can cause irritation, drying, and even nosebleeds, or in rare cases, perforation.

So where do you aim?

You aim towards the outer wall of your nostril, kind of towards your ear on the same side, and then you sniff gently.

Sniff gently.

Don't snort it into your brain.

Exactly.

You just want it to coat the nasal passages, not have it all run down the back of your throat.

Any major side effects we need to know about?

Usually they're pretty mild, since it's a topical application.

You might get a headache, some nasal irritation, pharyngitis.

But here's a weird one the text mentions.

Candidiasis.

A fungal infection in your nose.

Yes.

A yeast infection.

Steroids suppress the immune system locally, right where you spray them.

Sometimes that allows the natural yeast in your body to overgrow in the throat or nose.

It's rare, but it's possible.

The text also mentions protein binding for some of these drugs.

It does.

It points out that Fluticasone and Womedasone have extremely high protein binding over 90 or even 99 percent.

What does that mean in plain English for a nursing student?

Why do they need to know that?

It means that even if some of the drug gets absorbed into your bloodstream,

almost all of it immediately gets bound up by proteins and becomes inactive.

This is actually a good thing.

It means the systemic bioavailability is very low, so you don't get the whole body steroid side effects like weight gain or immune suppression that you get from taking a steroid pill like prednisone.

Got it.

So it's safe, it's local, and it's anti -inflammatory.

Now, section six.

We've cleared the nose.

Now we have to deal with the noise.

The cough.

Antitisives and expectorants.

Two types of drugs with completely opposite goals.

Antitisives suppress the cough.

Expectorants help you cough more effectively.

Let's start with antitisives.

How do they actually stop a cough?

It feels like such a primal, uncontrollable reflex.

It is primal.

These drugs act on the cough control center in the medulla of the brain.

The medulla, the brain stem.

Right.

Think of the medulla as the air traffic control tower for your body's reflexes.

The antitesive drug calls the tower and says, hey, ignore that little tickle signal coming from the throat.

Don't send out the command to cough.

It raises the cough threshold.

But do we always want to stop a cough?

Isn't it there for a reason?

No, we don't.

And the text is very firm on this.

Coughing is a naturally protective mechanism to clear the airway of mucus, debris, whatever.

If you have a productive cough, meaning you are coughing up gunk,

you generally want to let that happen.

You don't want that stuff sitting in your lungs.

So when do we use an antitesive?

For a non -productive, irritating cough, the kind that is dry, tickly, keeps you awake all night and makes your throat hurt but doesn't bring anything up.

That's the kind of cough we want to suppress.

The text lists three types.

Non -narcotic, narcotic, and combination products.

Who is the prototype drug here?

The prototype non -narcotic is dectromythorfenhydrobromide.

This is the one you see in almost every over -the -counter cough syrup.

Just look for the letters DM on the box.

And pharmacokinetically, how does it look?

It has rapid absorption.

The onset is about 15 to 30 minutes.

And the duration is three to six hours.

Any big interactions we need to flag?

Yes.

And it's that same dangerous one we've seen before, MAOIs.

Combining dextromythorfen with MAOIs can cause hypotension, hyperpyrexia, which is an extremely high fever, and serotonin syndrome, which can be fatal.

And there is a specific food interaction mentioned as well.

Grapefruit juice.

Of course.

The villain of pharmacology strikes again.

It really is.

Grapefruit juice can interfere with the metabolism of the drug in the liver, leading to toxicity.

And in this case, toxicity can look like hallucinations and seizures.

That is terrifying.

Hallucinations from cough syrup and a glass of grapefruit juice.

It's a very real risk.

What about the narcotic antitussives?

That would be codeine and hydrocodone.

These are much stronger.

They also work on the medulla, but they are opioids.

And because they are opioids, they come with all the opioid problems.

Exactly.

Respiratory depression is the big, life -threatening risk.

And also, dependence.

The text specifically warns that codeine preparations can lead to tolerance and physical dependence.

That's why they are controlled substances, schedule 2 on their own, or schedule V if they're mixed in very small amounts with other medications.

OK, let's flip the script.

Expectorants.

The goal here is the exact opposite.

We want to help the patient cough.

Expectorants work by loosening bronchial secretions so they can be eliminated more easily.

And the key drug here is guifanesin.

Right.

It works by reducing the viscosity and the adhesiveness of the secretions.

In other words, it makes the mucus thinner and less sticky, so when you cough, it actually moves and comes out.

But there's a huge pro tip in the text here.

It says guifanesin isn't enough on its own to really work well.

This is my favorite little nugget of information in the whole chapter.

The text says, hydration is the best natural expectorant.

Just drink your water.

That's it.

Patients taking expectorants should be taught to increase their fluid intake to at least 8 glasses per day.

If you are dehydrated, your mucus is like cement.

Guifanesin can't fix cement.

You need water to help thin it out.

That makes perfect sense.

Moving on to section 7, which covers other upper respiratory disorders.

Specifically, sinusitis and acute pharyngitis.

Right.

Sinusitis is simply inflammation of the sinuses.

The maxillary, frontal, ethmoid, or sphenoid sinuses.

It's painful.

A lot of pressure.

And how do we treat it?

Usually, we just support the patient through it.

Systemic or nasal decongestants can help drain the sinuses, acetaminophen, or ibuprofen for the pain, plenty of fluids, and rest.

Antibiotics are generally reserved only for acute or severe cases that aren't clearing up on their own.

Then there's acute pharyngitis, a sore throat.

This is a tricky one for diagnosis because you absolutely cannot tell the cause just by looking at it.

It can be viral, which is most common, or it could be bacterial specifically caused by beta -hemolytic streptococci.

Which is a drop throat.

Exactly.

Strep throat.

So if a patient comes in with a red, angry -looking sore throat, the nurse can't just say, oh, that looks like strep.

Absolutely not.

You need a throat culture, a rapid strep test, or a full culture.

That is the only way to differentiate.

And why is that differentiation so critically important?

Because of the treatment.

If the culture is positive for strep bacteria, you prescribe a 10 -day course of antibiotics.

But, and the text puts this in bold letters, antibiotics are not effective for viral pharyngitis.

I feel like we say this in almost every deep dive, but it bears repeating.

Do not throw antibiotics at a virus.

It doesn't help the patient.

It can cause side effects like diarrhea.

And it contributes to the global problem of antibiotic resistance.

For viral pharyngitis, you treat the symptoms.

Saline gargles, lozenges, fluids, pain relievers.

You treat the symptoms, not the bug.

All right, we have covered the anatomy, the diseases, and all the drugs.

Now, section eight.

This is where the rubber meets the road.

The nursing process and clinical judgment.

This is the section that turns you from a person who memorized a list of drugs into a nurse who can safely care for a patient.

And the core concept the book uses here is gas exchange.

Under assessment, or recognizing cues,

what are the first things a nurse should be looking for?

Baseline vital signs are number one.

You have to know where the patient is starting from.

The text notes that an elevated temperature, specifically greater than 99 to 101 degrees Fahrenheit, often indicates a viral infection.

We also need a really rigorous drug history.

Yes.

We've mentioned MAOIs about five times today because the interactions are so incredibly dangerous.

You have to ask specifically,

are you taking any medications for depression, any MAOIs, before you even think about suggesting a decongestant or a cough syrup?

And we also need to assess the patient's existing health conditions.

Right.

Does this patient have a history of hypertension?

If so, we need to think twice about that decongestant.

Do they have issues with urinary retention?

Maybe an antihistamine isn't the best choice.

We have to connect the drug's side effects to the patient's specific vulnerabilities.

Let's move to patient teaching.

The text provides a massive list of teaching points.

This is so important.

I want to kind of role play this to make it real.

I'll be the patient.

You be the nurse.

All right.

Let's do it.

OK, nurse.

I just picked up this Benadryl for my allergies, but I have a long commute to work tomorrow morning.

Is that going to be OK?

I would strongly advise against that.

Defenhydramine causes significant drowsiness in most people.

You should avoid driving a motor vehicle or operating any kind of dangerous machinery until you know exactly how this drug affects you.

It would be much safer to take it for the first time when you are staying home for the day.

OK.

Well, I'm also going to give it to my six -year -old because he's just bouncing off the walls and I need him to get some sleep.

Actually, that might backfire on you.

In children, antihistamines can sometimes cause what we call a paradoxical reaction.

So instead of getting sleepy, they might have nightmares, become nervous, or get even more irritable and excitable.

Oh, wow.

Good to know.

OK, switching gears.

I'm 75 years old and this medicine makes me feel a little dizzy and confused.

Is that normal?

It is a very common side effect in older adults.

You're more sensitive to these effects.

If you feel dizzy or confused, please be very, very careful when standing up to avoid falls.

If it continues, we should talk to your provider about switching you to a different medication that might be safer for you.

My mouth is so dry I can barely swallow.

That's that classic anticholinergic effect.

A good tip is to try using sugarless candy, chewing gum, or sucking on ice chips.

It can really help keep your mouth moist.

OK, I've bought this nasal decongestant spray.

It works great.

I'm just going to use it every day until spring comes.

No, you absolutely must not do that.

You need to limit the use of that spray to a maximum of three days.

If you use it any longer, your nose can essentially get addicted to it, and you'll get something called rebound congestion that can be even worse than when you started.

Understood.

Three days only.

Last corrosion.

My throat is killing me.

Can you just call in some antibiotics for me?

I understand you want to feel better, but I can't.

Antibiotics do not kill viruses, and viruses cause more sore throats.

We need to do a throat culture first to see if it's a bacterial infection -like strep.

If it is, we will absolutely get you antibiotics.

But if it's a virus, antibiotics won't help you and could cause other problems.

End scene.

That was a perfect summary of the key teaching points.

Those are the conversations you will actually have with patients every single day in almost any setting.

Let's look at the case study presented in the text to bring it all together.

OK.

So we have a 35 -year -old female patient.

She has a history of allergic rhinitis.

And what has she been prescribed?

She's prescribed loratadine, five milligrams a day, and fluticazone, two nasal inhalations per day.

She then asks the nurse if she can continue to take her other over -the -counter drugs with these new prescriptions.

And this is a classic clinical judgment moment.

The nurse can't just say yes or no.

The nurse needs to ask, what OTC drugs are you taking?

If she's taking Benadryl on top of loratadine, she's double -dosing antihistamines.

If she's taking a systemic decongestant, we need to check her blood pressure first.

The only right answer is, let's review exactly what you want to take so we can make sure it's safe.

His study also notes she has never used a nasal inhaler before.

So that's a perfect teaching opportunity.

We have to demonstrate it.

Clear the nose first.

Aim the spray away from the septum.

Sniff gently.

Don't blow your nose immediately after using it.

And then the text asks us to compare loratadine versus defenhydramine for this specific patient.

Right.

So she's 35.

She's likely active, working, driving.

Loratadine is a second -generation antihistamine.

It has a long half -life, so it's once a day.

And it has much less drowsiness.

Difenhydramine is short -acting and very sedating.

For a daily maintenance drug for allergies, loratadine is clearly the superior choice for her lifestyle and safety.

Makes perfect sense.

Before we let the listeners go, let's run through the review questions at the end of the chapter.

Let's do a little rapid fire.

All right.

Hit me.

Question one.

A patient is taking defenhydramine.

What is the most important safety instruction?

A.

Take on an empty stomach.

B.

Avoid driving until stabilized.

C.

Nightmares are likely in adults.

D.

It causes excessive secretions.

It has to be B.

Avoid driving.

Safety is always priority number one, and drowsiness is the biggest immediate risk.

D is the opposite of the truth.

It drives secretions.

Question two.

A patient has a sore throat caused by beta -hemolytic streptococcus.

What is this condition called?

A.

Rhinitis B, sinusitis C, pharyngitis D, rhinorrhea.

That is C, pharyngitis.

Strep throat is an infection of the pharynx.

Question three.

A patient is prescribed oxymethasoline nasal spray.

What do you teach them?

A.

Take at bedtime for drowsiness.

B.

Spray away from the septum.

C.

Use for asthma maintenance.

D.

Limit use to three days.

This one is a little tricky because B is also correct technique, but D limit use to three days is the critical safety constraint to prevent a whole new problem, that rebound congestion.

So D is the priority answer here.

Question four.

A patient is prescribed guifanesin.

What is the purpose of this drug?

A.

Treat allergic rhinitis.

B.

Loosen bronchial secretions.

C.

Compete with histamine.

D.

Cause vasoconstriction.

B.

Loosen bronchial secretions.

It is an expectorant.

C is an antihistamine.

D is a decongestant.

Question five.

A patient is prescribed beclomethasone for allergic rhinitis.

What do you teach them?

A.

Use for acute attacks.

B.

Use the oral form, if preferred.

C.

Avoid caffeine.

D.

With continuous use, nasal dryness may occur.

It's D.

With continuous use, dryness of the nasal mucosa may occur.

It's a common side effect of the steroid.

And it's definitely not for acute attacks.

And finally, question six.

Teaching for diphenhydramine.

Select all that apply.

A.

Take on an empty stomach.

B.

Avoid alcohol and other CNS depressants.

C.

Notify the provider if confusion or hypotension occurs.

D.

Use sugarless candy for dry mouth.

E.

Avoid operating dangerous equipment.

I'm selecting B, C, D, and E.

Avoid alcohol because of the CNS depression.

Notify the provider of serious side effects like confusion.

Use sugarless candy for the anticholinergic dry mouth.

And definitely avoid dangerous equipment due to the sedation.

A perfect score.

It helps that we just spent an hour breaking down the chapter.

It does.

But seriously, we covered a lot of ground today.

We went from the basic anatomy of the upper airway through the viral physiology and deep into the pharmacology of antihistamines, decongestants, steroids, and cough meds.

And we didn't just list them.

We tried to explain why they work.

And that's really the key to pharmacology.

If you understand the why,

like knowing that first gen antihistamines cross the blood -brain barrier, which causes drowsiness, or that alpha adrenergic stimulation constricts blood vessels, you don't have to memorize nearly as much.

It just makes physiological sense.

So as we sign off, I want to circle back to that $60 billion figure.

The cold and flu aisle.

The cold and flu aisle.

The next time you are standing in that aisle, just staring at a wall of colorful boxes, remember this deep dive.

Don't just grab the multi -symptom maximum strength box that has four or five different drugs in it.

Think critically.

Ask yourself, what is my actual problem right now?

Do I have a dry hacking cough?

Get a suppressant.

Do I have a wet productive cough?

Get an expectorant and drink a gallon of water.

Is my nose running like a faucet?

Antihistamine.

Is it completely stuffed up decongestant?

Treat the specific symptom.

Avoid the shotgun approach.

It saves you money and it saves your body from unnecessary side effects from drugs you don't even need.

And please, for safety, always check the label for acetaminophen if you are taking Tylenol separately.

It's so easy to accidentally double dose and hurt your liver.

That is a great final tip.

Thanks for listening to this deep dive last minute lecture edition.

Good luck with your studies and please wash your hands.

Good luck.

You've got this.