Chapter 15: Antidepressant Drugs

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Welcome back to the Deep Dive.

Today, we are metaphorically pulling an all -nighter.

We really are.

We're tackling a topic that is quite frankly a beast.

We are looking at Chapter 15 of Psychiatric Nursing, the seventh edition.

Yep, the big one.

And if you are a nursing student staring down a pharmacology exam or maybe a medical professional just brushing up, or even just someone trying to understand the chemistry inside your own medicine cabinet, this one is specifically for you.

It really is a massive topic.

We are talking about antidepressant drugs.

Yeah.

And we're going to treat this session like a last -minute lecture.

Oh yeah.

We know the reality.

The exam is coming up.

Maybe your psychiatric clinical rotation starts tomorrow morning at 7 a .m.

and you just need to download this information into your brain as efficiently as possible.

Exactly.

And the mission today is pretty clear.

We aren't just here to memorize a laundry list of chemical names.

No, that's the old way.

That's the old way of studying.

And it doesn't stick.

We need to understand these drugs as tools.

These are tools designed to restore quality of life, but, and it's a big but,

they are tools that come with a minefield of side effects, safety concerns, and some incredibly complex biology.

And it's not just about the chemistry equations.

I mean, if you look at the learning objectives for this chapter, they're pretty broad.

We need to understand the neurobiologic theories, basically, why we think depression even happens in the brain.

Right, the foundational stuff.

And we need to differentiate the classes, moving from the modern SSRIs that everyone knows and then going back to the old school MAOIs.

And crucially, for all the nurses listening, you have to be able to recognize toxicity and master the art of patient teaching.

Before we even get to the molecules, I want to start with something from the text called Norm's Notes.

I love this section because it just sets the scene so perfectly.

Norm points out that these drugs are absolutely everywhere in our society.

They really are ubiquitous.

It's kind of staggering when you look at the numbers.

The text notes that antidepressants are the third most common type of prescription in the United States.

The third.

That's huge.

That is a massive market share of medicine.

Yeah.

But the statistic that really jumps out at me is the growth rate.

Between 1988 and 2008, the use of these drugs increased by 400%.

400%.

That's not a small number.

That is a staggering figure.

It implies a fundamental shift in how we treat mental health or maybe even how we define it.

It does.

And Norm makes a critical, almost philosophical point here.

He says, and I'm paraphrasing,

I'd be very surprised if you didn't know someone taking one of the SSRIs.

That's true for me.

I bet it's true for everyone listening.

It's become a cultural norm.

But he adds this layer of caution.

He questions whether we are sometimes just numbing oneself to avoid some pain rather than actually working through our problems.

He calls them great drugs when really needed, but potentially overused.

That's a really important nuance to keep in the back of your mind as we go through all the hard pharmacology.

We are treating a medical condition, yes, but we have to make sure we aren't just masking the human experience.

Okay.

So let's look at the roadmap for this deep dive.

We're going to follow the chapter structure strictly so you can follow along at home.

We'll start with the brain biology, move to the SSRIs, since those are the most common, then we'll hit the novel drugs and finish up with the older riskier classes like TCAs and MAOIs.

Sounds like a solid plan.

You have to build the foundation first.

So let's start with the biology.

Section one,

the biological basis of depression.

For the longest time, the prevailing theory has been something called the Monoan hypothesis.

What's the story there?

This actually goes back

about 60 years, and it kind of starts with a happy accident or maybe an unhappy one, depending on how you look at it.

It started with a drug called reserpine.

Back in the early 1950s, doctors were using reserpine to treat high blood pressure hypertension,

and it worked for the blood pressure, but researchers started noticing something.

Well, something alarming in the patients taking it.

They were fixing the heart, but breaking the mind?

Essentially, yes.

Patients developed profound depression.

Some even became suicidal.

So when they looked at what reserpine was actually doing in the brain, they found it was depleting norepinephrine.

So there's the connection.

That one observation birthed the Monoamine hypothesis.

The core concept is, on the surface, very simple.

Depression is caused by a deficiency of specific neurotransmitters.

A lack of chemicals.

Exactly.

Specifically, norepinephrine, serotonin, and dopamine.

The idea is, if you don't have enough of these chemical messengers floating around in the synaptic gap, you get depressed.

That seems incredibly logical.

It's almost like a math equation.

If the drug that drains them causes depression, then drugs that boost them should cure depression.

You think so.

But the text throws a bit of a wrench in this, doesn't it?

It mentions Dr.

Alan Gallenberg and something he calls the aspirin analogy.

I love this analogy because it forces you stop and think critically about cause and effect.

Dr.

Gallenberg argues that just because SSRIs, which boost serotonin work to relieve depression, that doesn't prove that depression is caused by serotonin deficiency.

Right.

And the analogy he uses is about headaches.

Exactly.

He says, it's like saying that a headache is an aspirin deficiency syndrome.

Think about that for a second.

Yeah, that makes sense.

If you have a throbbing headache and you take an aspirin and the headache goes away,

it doesn't mean your body was suffering from a lack of aspirin.

Of course not.

It just means aspirin is an effective intervention for the pain.

So while the neurotransmitter theory is a useful model, it might not be the whole story.

Which brings us to the newer theory discussed in the chapter, which involves the second messenger system.

This is where we need to look at figure 15 to 1 in the text.

This gets a bit technical and I think a lot of students might gloss over it, but why is this actually so important?

It is absolutely vital because it explains the lag time.

This is probably the number one question patients ask.

We know that when you take an antidepressant, your neurotransmitter levels rise within hours.

Almost immediately.

Right.

The chemistry changes almost immediately, but patients don't feel better for weeks, often two to four weeks, sometimes even longer.

Why is that?

Because if it was just about filling up the tank with serotonin, they'd feel better by the afternoon.

Precisely.

So the second messenger theory suggests the real magic, the real change, is happening deeper inside the neuron.

Let's try to visualize figure 15 to 1 for everyone.

Imagine a chain reaction,

like dominoes falling.

Okay.

Step one.

The neurotransmitter, let's say serotonin, binds to the receptor on the outside of the cell wall.

This is like the knock on the door.

Got it.

Step two.

That knock activates something called a G protein that's sitting just inside the membrane.

Step three.

The G protein then activates an enzyme, usually one called adenyl cyclase.

Step four.

That enzyme creates a second messenger, usually something called CAMPP.

Okay, so it's like a corporate bucket brigade.

The neurotransmitter knocks on the door, the G protein answers, tells the enzyme to get to work, and the enzyme sends a memo, the CAMPP, further into the office.

That is a great way to visualize it.

And that memo, the CAMPP, it goes on to activate something called protein kinase.

Now, here's the payoff.

This is the whole point.

That protein kinase eventually marches right into the nucleus of the cell, the command center, and it hits the DNA.

It activates a transcription factor.

So the end result of taking an antidepressant is actually genetic.

You're changing how the cell reads its own blueprint.

Yes, exactly.

The final step is genetic output.

The cell starts synthesizing new proteins.

This is why it takes weeks.

You aren't just filling up a make the RNA and then build new structures.

And one of the most important things being produced here is something called BDNF.

Brain -derived neurotrophic factor.

This is huge in modern psychiatry.

The theory is that in depression, the brain is under -synthesizing these critical proteins that keep neurons alive and healthy.

Without enough BDNF, neurons can actually undergo apoptosis.

Program cell death.

Program cell death.

They wither away.

They lose connections.

So depression might essentially be neurons dying off or just failing to connect with each other properly.

But that's the hypothesis.

Yeah.

And antidepressants, by triggering this whole complicated second messenger system, they increase BDNF production.

They stop the cell death and encourage synaptogenesis, the growth of new connections, new synapses.

So you're literally healing the brain structure, not just balancing the chemicals on the surface.

That makes the two to four week lag time make so much more sense.

You can't grow new synapses overnight.

That is a physical growth process.

Okay.

Let's move from the theory to the drugs themselves.

We are starting with the big guns.

The first line treatment, the SSRIs.

Selective serotonin reuptake inhibitors.

These are the household names.

Prozac, Zoloft, Paxil, Selexa.

They are the first choice for the vast majority of prescribers today.

So why are they the favorite?

Is it just habit or is there a real pharmacological advantage?

Oh, there's a real advantage.

It all comes down to the side effect profile.

They are effective, yes, but compared to the older drugs we'll talk about later, they are much, much cleaner.

Cleaner how?

They're more selective.

They do one job and they do it well.

They block the reuptake of serotonin.

They don't have the heavy anti -cholinergic effects, you know, drying you out or the cardiovascular toxicity that the older drugs do.

They don't bind significantly to histamine or adrenergic receptors.

So you get and less of that blood pressure dropping.

But safer doesn't mean risk -free.

The text highlights a very, very serious black box warning.

This is something every single nurse needs to memorize verbatim.

Absolutely.

This is the most serious warning the FDA can put on a prescription medication.

Antidepressants carry a black box warning regarding the increased risk of suicidal thinking and behavior in children,

adolescents, and young adults,

specifically that 18 to 24 age This is a paradox that terrifies families and frankly it terrifies clinicians.

You give a drug to treat depression and suicide and the warning says it might cause it.

What is the clinical thinking behind why this happens?

It's a subject of intense debate, but one of the prevailing theories is the energizing effect.

When a patient is profoundly depressed, they often have suicidal thoughts.

But, and this is the key, they lack the energy or the volition to act on them.

They're in state of psychomotor retardation.

Exactly.

They can barely get out of bed, let alone plan and execute a suicide.

They are, in a way, paralyzed by the depression itself.

But when you start an SSRI, specifically one of the more activating ones like fluoxidine Prozac, the energy might return before the mood improves.

The physical get up and go returns before the hope returns.

That's a dangerous combination.

It's incredibly dangerous.

Suddenly you have a patient who is still feeling despair, still feeling hopeless, but now they have the energy to cure at a plan.

That is terrifying.

It means that the moment they start looking like they're getting better physically is actually the most dangerous time psychiatrically?

Correct.

That's why close monitoring in the first few weeks is completely non -negotiable.

You can't just hand over a script and say see you in a month.

It's just not safe.

There is also a discussion in the text about violence and aggression.

It mentions anecdotal reports and the text actually points to a website called ssrisstories .com forward slash linking SSRIs to apathy, indifference, or a kind of disinhibition that could lead to violence.

It does.

It lists some scary headlines.

School shootings attributed to people on these meds.

It mentions a case from January 2008 where a student took a shotgun to school and another in Germany where 16 people were killed.

But how solid is that link?

Well, the text notes that it's very difficult to scientifically prove a direct cause and effect relationship because the person was by definition already mentally ill.

But the antidepressant apathy syndrome is a recognized phenomena.

And what does that look like?

Patients can just stop caring.

They lose motivation.

They become indifferent to things that used to matter to them.

If you combine that profound indifference with disinhibition, you can see where the concern comes from.

Let's talk about the more common side effects.

The ones that might not be life -threatening but are definitely lifestyle -threatening.

The ones that make people want to stop taking the pills.

Right.

The big one is GI issues.

Nausea, loose stools, diarrhea.

This happens because most people think serotonin is just a brain chemical.

But actually, the vast majority of your body's serotonin,

it's in your gut.

I think most people don't know that.

They don't.

We have serotonin receptors all through our gut, the 5 -HD3 receptors.

So when you take a drug that boosts serotonin everywhere, you're going to stimulate the gut.

So you are essentially giving the gut a serotonin overdose, in a way.

But the one that affects compliance the most, the reason people stop taking the pills without telling their doctor, is probably the sexual dysfunction.

Without a doubt.

The text states that 50 % or more of patients experience this.

It's not rare, it's the norm.

We're talking decreased libido, impotence, ejaculatory delay, and inability to

orgasm.

It's related to the activation of 5 -HT2 receptors in the spinal cord.

And if you are depressed and the pill that's supposed to make you feel better also makes you unable to have a sex life, that's not exactly a mood booster.

It feels like a really cruel trade -off.

It is.

It leads to a lot of people stopping their meds without telling their doctor, which is also dangerous.

The text does suggest some strategies, though.

You can wait and see.

Sometimes the body adapts over a few months.

Or you can lower the dose.

You can lower the dose.

Or you can add an antidote.

Like sildenafil.

Yes, Viagra.

And interestingly, the text makes a point to mention that sildenafil has been shown to be effective for women suffering from antidepressant -induced anorgasmia, not just for men with erectile issues.

That's a key piece of information for patient teaching.

And another strategy is adding bupropion.

Right.

Well, butrin.

We'll discuss it more later.

But because it boosts dopamine, it can sometimes counteract those serotonin -based sexual side

There is also a warning, a big one, in Box 15 -3 about stopping these drugs too fast.

It's called the withdrawal syndrome.

Yeah, this is really uncomfortable for patients, and they need to be warned about it.

If you stop an SSRI abruptly, especially one with a short half -life, you can get dizziness, nausea, lethargy, and flu -like symptoms.

But there are also psychological symptoms like anxiety and intense irritability.

And those brain zaps.

And patients describe these sensory disturbances they often call electric shock sensations in the head or brain zaps.

I've heard patients describe it like a literal jolt of electricity.

That sounds awful.

It's physically startling.

And it's why tapering is so, so important.

You have to wean off these medications slowly over weeks, sometimes months.

Now we have to talk about the most dangerous acute reaction, serotonin syndrome.

Box 15 -7 covers this, and it's a must -know.

Serotonin syndrome is a true medical emergency.

It can be fatal.

It happens when you have way too much serotonin accumulating in the brain.

This usually happens if you mix an SSRI with something else that also boosts serotonin.

Like what?

Like an MAOI, which is the classic deadly combo, or lithium tryptophan supplements, or even herbal stuff like St.

John's wort.

The text uses a specific case study to illustrate this.

The story of Libby Zion.

This is a story that every medical resident knows, or at least they should.

It's a tragic historic case that changed medicine.

Libby Zion was an 18 -year -old college freshman.

She went to the ER in New York back in 1984 with agitation and a fever.

She was taking an MAOI called phenolzine for her depression.

Okay.

The residents in the hospital who were overworked and exhausted working 100 -hour weeks, they gave her maparadine, which is Demerol, for her shaking and agitation.

And that combination is deadly.

It is the cardinal sin of psychopharmacology.

You never, ever mix an MAOI and Demerol.

The mix caused massive serotonin syndrome.

Her temperature went to 103 .5 degrees hyperthermia.

She had muscle rigidity, strange jerking motions, and she died.

Wow.

Her death actually led to the reform of medical residency work hours because the residents were just so exhausted they missed the interaction.

But it also put serotonin syndrome on the map for every clinician.

So what are the symptoms nurses need to watch for?

If you are on the floor, what does this look like in a patient?

Remember the triad.

It's a good way to organize it.

First, cognitive effects,

mental confusion, hallucinations, extreme agitation.

Second, autonomic effects, shivering, sweating, hyperthermia, tachycardia.

And third, somatic effects,

muscle twitching, hyperreflexia, where the reflexes are way too jumpy and tremors.

So if you see a patient on an SSRI who suddenly starts shivering, twitching, and getting confused, you need to sound the alarm.

Fast.

Immediately.

Okay, let's do a roll call of the specific SSRIs mentioned in the text.

There are a few nuanced differences that are definitely fair game for an exam.

Let's start with citalopram, Selexa, and acetylopram, Lexapro.

The text has this great visual explanation about mirror images.

This is pure chemistry, but it really explains the marketing and the difference in dosing.

Citalopram or Selexa is what we call a racemic mixture.

It's a mix of two isomers.

Isomers.

Think of them as a left hand and a right hand.

They're mirror images of the same molecule, but they're not identical.

You have the R isomer, the right hand, and the S isomer, the left hand.

And they aren't created equal in terms of effect?

Not at all.

The R side is largely responsible for the side effects, especially some of the cardiac concerns.

The S side is the one that gives you the therapeutic benefit.

So Selexa has both.

It's a 50 -50 mix.

But acetyltomlexapro is just the S isomer.

The S in the citalopram literally stands for S isomer.

So by removing the dirty R side, you get a cleaner drug.

Exactly.

Lexapro is cleaner.

It requires a lower dose, usually half the dose of Selexa, and it generally has a better side effect profile.

It's a more refined version of the same drug.

Okay.

What about fluoxetine or Prozac?

That's the grandfather of them all.

Think of Prozac as the long hauler.

It has a massive half -life.

It and its active metabolite stay in your system for 10 days or even longer.

So what does that mean clinically?

It makes it great for patients who are forgetful or maybe not the most compliant.

If you miss a dose of Prozac, it's not a disaster because you still have plenty in your blood.

But the flip side is if you need to switch meds, you have to wait a very long time, a long washout period of up to six weeks before starting something like an MAOI, or you risk that serotonin syndrome we just talked about.

Got it.

Then there is sertraline or Zoloft.

Very widely used.

A solid workhorse drug.

It can be taken with or without food.

But the text specifically notes that sexual dysfunction is very common with Zoloft.

So that's a big patient teaching point.

You have to warn them about the libido issues right up front.

And finally, peroxetine or Paxil.

This one is tricky.

It is very potent, but it has a short half -life.

So the withdrawal is worse.

Much worse.

If you miss a dose of Paxil, you feel it fast and hard.

Also, and this is crucial, the FDA issued a specific warning that it is linked to birth defects, specifically cardiac defects.

It's rated category D for pregnancy.

Most other SSRIs are category C.

So you really want to avoid Paxil in women of childbearing age if at all possible.

That's a huge clinical pearl right there.

Okay, that covers the SSRIs.

Let's move to section three.

The novel and other classes, these are the ones that tweak the formula a bit.

Let's start with the SNRIs.

The serotonin or penephrine reuptake inhibitors.

The big ones here are venlafaxine,

and deloxetine.

Symbolta.

The name says it all.

They hit both serotonin and norepinephrine.

Right.

The idea here was to combine the efficacy of the older tricyclic drugs, which also hit both neurotransmitters, but with the safety and tolerability of the SSRIs.

The goal was to get that dual action without all the side effects.

But venlafaxine or Effexor has a weird dosing quirk that nurses absolutely need to know.

It does.

Its action is dose dependent.

At low doses, say 75 mg, it acts basically just like an SSRI.

It mostly hits serotonin.

At medium doses, maybe 150 mg, it starts to recruit norepinephrine.

And at very high doses, it even tickles dopamine a little bit.

What's the catch?

Why not just give this to everyone if it hits more targets?

The blood pressure.

Because you are boosting norepinephrine, which is a stress hormone related to adrenaline, you can see an increase in blood pressure, especially those higher doses.

So monitoring BP is essential with Effexor.

Okay.

Andiloxetine or Cymbalta?

Cymbalta is interesting because it's also approved for neuropathic pain.

Like from diabetes.

Exactly.

Like diabetic neuropathy or fibromyalgia.

So if you have a patient who is depressed and also has chronic pain, this drug can kill two birds with one stone, which is a huge benefit.

Next up is the NDRIs, specifically bupropion or wellbutrin.

This is the rebel of the group.

It is the only major antidepressant that primarily targets dopamine and norepinephrine, but has virtually no effect on serotonin.

Which explains what the text calls the happy side effects.

Yes.

It's a great name for them because it doesn't hit serotonin.

You don't get the sexual dysfunction.

In fact, by boosting dopamine, it often enhances libido.

And unlike many of the SSRIs, which can cause weight gain, bupropion is associated with weight loss.

It acts as an appetite suppressant.

And it's marketed under a different name for something else entirely, right?

XiBan.

It's the same molecule, but it's marketed as XiBan for smoking cessation.

It helps stop nicotine cravings, again, probably through its action on dopamine pathways.

So it sounds perfect.

Better sex, weight loss, no smoking.

Why isn't everyone on this drug?

Because of the seizure risk.

This is the big contraindication.

Bupropion lowers the seizure threshold more than other antidepressants.

So if a patient has a history of seizures, a history of head trauma, or an active eating disorder like bulimia, which can mess with electrolytes and seizure thresholds, you absolutely cannot give them this drug.

It's strictly contraindicated.

Got it.

Then we have mirtazapine or remeron.

This one's mechanism is different.

It has a very unique mechanism.

It's an alpha -2 antagonist.

Think of the alpha -2 receptor as a brake pedal on the neuron.

When it's stimulated, it tells the neuron,

okay, stop releasing chemicals.

Mirtazapine cuts the brake line.

It blocks that receptor.

So the neuron just keeps releasing more serotonin and norepinephrine.

And the side effect profile is, well, it's distinct.

Very distinct.

Sedation and weight gain.

And not just a little bit.

Significant weight gain.

It stimulates appetite and causes sedation because of its powerful antihistametic effects.

That sounds terrible.

Who wants to be tired and fat?

For a young active person, probably not.

But you have to think about the clinical picture.

Imagine you have an elderly patient in a nursing home who is depressed, anxious, can't sleep, and is losing weight because they refuse to eat.

They are failure to thrive.

Ah, I see.

For that specific patient, remeron is a magic bullet.

It helps them sleep, it helps them eat, and it treats the depression.

It's a great example of matching the drug's side effect profile to the patient's needs.

That makes perfect sense.

And finally, in this group, trazodone.

Yeah, trazodone.

It's rarely used for depression anymore.

To get an antidepressant effect, you'd have to take huge doses that would knock you out completely.

But it is very, very commonly used as a non -addictive sleep aid in lower doses.

It causes sedation without the addiction risk of Ambien or benzodiazepines.

Alright, let's travel back in time to the old guard, section 4.

The tricyclic antidepressants, or TCAs.

These are drugs like amitryptaline, Elavil,

and imirpamin, tolferanil.

These were the standard care before Prozac arrived in the late 80s.

They work, but they come with problems.

The text calls them dirty drugs, and that sounds judgmental, but it's a real pharmacological term.

It is.

In pharmacology, dirty just means they aren't selective.

And SSRI is like a sniper.

It hits the serotonin transporter and leaves most everything else alone.

A TCA is like a shotgun blast.

It hits serotonin and norepinephrine reuptake, which we want, but it also hits histamine receptors, acetylcholine receptors, and alpha -edrenergic receptors, which we definitely don't want.

And hitting all those other receptors is what causes the side effect burden.

Let's break that down.

First, the anti -cholinergic effects.

This is a favorite test question topic.

Oh, always.

Blocking acetylcholine causes the classic anti -cholinergic profile.

The mnemonic is can't see, can't pee, can't spit, can't defecate.

So you get dry mouth, blurred vision.

Dry mouth,

severe constipation, and urinary retention.

The text has a specific nursing note about older men here.

That seems really important.

Yes.

Urinary retention is a major risk for older men with enlarged prostates, or BPH.

If you give them a TCA, their bladder might just shut down completely.

It can become a medical emergency requiring a catheter.

Then there's the cardiovascular toxicity.

This is what makes them so scary.

TCA's have what's called a quinidine -like effect.

They act like an antiarrhythmic drug by slowing down electrical conduction in the heart.

It disrupts the sodium channels.

This can cause heart block and deadly arrhythmias.

You need a baseline EKG before starting one.

And orthostatic hypotension.

That's from blocking the alpha -1 adrenergic receptors.

When the patient stands up, their blood vessels don't constrict, like they should, to push blood up to the brain.

So the blood just pools in their leg?

Exactly.

Blood pools in the blood pressure plummets, and they get dizzy or faint.

For an elderly patient, a fall in a broken hip can be a death sentence.

It's a huge risk.

This leads us to the suicide paradox, which is visualized in figure 15 -4 of the text.

This is the most dangerous aspect of TCA's, and it's the main reason they aren't first line anymore.

They have a very narrow therapeutic index.

Which means?

Which means the dose that helps you is dangerously close to the dose that can kill you.

How close are we to the patient?

The patient can be fatal if the patient takes it all at once.

So you are literally handing a suicidal patient a bottle of pills that represents a loaded gun.

That is the paradox, exactly.

With SSRIs, it is very, very hard to overdose fatally on the pills alone.

You might get really sick, but you likely won't die.

With TCA's, severe cardiac toxicity and death can occur at blood levels of just a thousand NGML.

It's incredibly dangerous.

Which is why nurses have to ensure patients aren't cheeking the pills.

Right.

Hiding them in their mouth to save them up for a massive overdose later.

It's a real concern in inpatient settings.

Let's quickly mention two specific TCA's from the text.

Amitriptyline or Eleville.

Highly sedating, very anti -cholinergic, and probably the most cardio toxic of the bunch.

It's tough on the body, but it is still used sometimes, often for chronic pain or migraines.

And Imipramine or Tofrenil.

That's the oldest one.

Interestingly, because of that anti -cholinergic side effect of urinary retention, it is sometimes used off -label for childhood bedwetting or inuresis.

It tightens the bladder sphincter.

That's fascinating.

Using a side effect as a treatment.

Okay, moving on to section five.

The nuclear option.

Monoamine oxidase inhibitors or MAOIs.

Drugs like phenylzine, nardal,

and traenylsipramine, Parnate.

These are very rare now.

They're reserved for treatment resistant depression or a specific subtype called atypical depression where nothing else has worked.

And how do they work?

The mechanism is totally different.

Totally different.

They inhibit the enzyme MAO, which stands for monoamine oxidase.

This enzyme is like the Pacman of the synapse.

It travels around eating up leftover neurotransmitters, serotonin, norepinephrine, and dopamine.

If you kill the Pacman, the levels of those neurotransmitters go way up because nothing is there to destroy them.

But the text is very clear that the effect is irreversible.

What does that mean?

That's the scary part.

The drug binds to the enzyme and permanently destroys it.

The body has to physically synthesize brand new enzyme molecules to recover function, and that takes about two weeks.

So even if you stop taking the drug today, the effect lasts for two more weeks.

This leads to the infamous hypertensive crisis and the teramine connection.

Can you explain this whole food issue?

Because it sounds like a myth, but it's dangerously real.

It is very real and very dangerous.

MAO isn't just in your brain.

It is also found in your gut and your liver.

Its job there is to break down teramine, which is an amino acid byproduct found in aged, rotting, or fermented foods.

If you are on an MAOI, you have no MAO in your gut to protect you.

You've lost your defense system.

If you eat a piece of aged cheese or some salami, the teramine isn't broken down.

It gets absorbed into your bloodstream intact, travels to your nerve endings, and acts like a bomb.

It displaces massive amounts of nori, pie, and fry in all at once.

And that causes...

Your blood pressure skyrockets instantly.

We are talking stroke -level hypertension.

It can cause a cerebral hemorrhage or a myocardial infarction.

It can kill you.

Box 15 -8 lists the forbidden foods.

It's basically a gourmet charcuterie board.

It's everything good.

It really is.

No aged cheese, so no cheddar, blue cheese, brie, even mozzarella.

No cured meat, so no salami, sausage, pepperoni, bologna, no tap beer or Chianti wine,

no soy sauce, no fava beans, no avocados or bananas if they are overripe.

Imagine telling a patient,

here is your antidepressant, but you can never have pizza and a beer again for as long as you take this.

It's a very hard sell.

That's why these are last resort drugs.

The patient education has to be perfect.

The symptoms of the crisis are a sudden, severe, throbbing headache, a stiff neck, and palpitations.

If that happens, it's a trip to the ER now.

And what's the treatment?

You need an alpha blocker like Fentolamine to lower the blood pressure immediately.

We already mentioned the drug interactions.

No SSRIs, no Demerol.

But what about over -the -counter cold meds?

Huge danger.

Over -the -counter cold meds often contain pseudoephedrine.

That is a powerful stimulant that can trigger the hypertensive crisis, just like Tiramine can.

Patients on MAOIs need to be educated to check every single label on every single thing they take.

They cannot just pick up DayQuil.

There is one loophole mentioned in the

Cilagelin MSAM pack.

This is a very clever delivery system.

It's a transtermal patch.

Because the drug absorbs through the skin, it bypasses the gut and the liver on its first pass.

So it doesn't knock out the gut enzymes.

At lower doses, like the 6mg patch, it doesn't inhibit the MAO in the intestine as much.

It leaves the gut enzymes alone to do their job with Tiramine.

That means the strict dietary restrictions aren't required at that low dose.

That's a huge game changer for that class of

meds.

Okay, we are in the home stretch.

Section 6, non -traditional approaches, and a final nursing wrap -up.

What about supplements?

The text mentions two important ones.

Vitamin D and L -methylfolate.

Vitamin D helps regulate tyrosine hydroxylase, which is the enzyme that makes dopamine and norepinephrine.

Low vitamin D levels have been linked to depression.

L -methylfolate is a form of folic acid that helps modulate the synthesis of neurotransmitters.

These are often used as adjuncts add -ons to make the antidepressants work better.

And there is a fascinating note about a really old drug, scopolamine.

Yes, this is so interesting.

Scopolamine is an ancient drug used for motion sickness.

It's usually a patch you put behind your ear for a cruise.

But recent studies at the NIH show that an IV infusion of it has rapid antidepressant effects, like within hours.

But it's an anticholinergic, and we've spent this whole time saying those effects are bad.

Right.

It's confusing.

We usually try to avoid those effects.

It just shows that we still have a lot to learn about how these systems really work.

It might be hitting a very specific receptor subtype we've been ignoring.

Finally, let's summarize the key nursing interventions from all the boxes in the chapter.

If you are a nursing student listening to this, what are your top three takeaways for your practice?

Okay.

Number one, start low, go slow, especially for the elderly.

Their livers don't metabolize as fast, and they are much more prone to side effects like falls from orthostatic hypotension.

Number two, manage expectations regarding the lag time.

You absolutely have to tell the patient, this will take two to four weeks to really work.

Please don't stop taking it because you don't feel better in three days.

That prevents so much non -compliance.

And number three, safety, safety,

safety.

Monitoring for suicide, especially in that first period when their energy returns.

Monitoring for orthostasis and falls,

and monitoring for toxicity like serotonin syndrome or hypertensive crisis.

That brings us to the end of the chapter.

It's been quite a journey through the pharmacopoeia from the brain all the way to the pharmacy.

To kind of recap the evolution, we went from the sledgehammer approach of the MAOIs and TCAs, which were effective but dangerous and dirty,

to the scalpel precision of the SSRIs and the novel drugs.

We're getting better at targeting the problem without causing so much collateral damage the rest of the body.

But the ultimate goal remains the same, right?

Biology and chemistry are just the tools.

The real goal is restoring the person.

Absolutely.

The pill is just the ladder to help them climb out of the hole.

The real work still needs to be done.

I want to leave you with a provocative thought, and it goes all the way back to Norm's notes at the beginning.

Anti -depressant usage is up 400%.

So the question is, are we treating a massive epidemic of chemical imbalance, or are we in some cases chemically numbing the pain of modern living?

And is the future of treatment simply adding more and more drugs, or is it in better understanding that genetic output theory, healing the neurons themselves so they don't need the drugs forever?

That is the million dollar question.

Are we curing, or are we just maintaining?

Something to mull over.

Thank you for diving deep with us.

A warm thank you from the Last Minute Lecture Team.

Good luck on that exam, or with that patient tomorrow.

Take care.