Chapter 41: Sleep Disorders – Pharmacologic Approaches

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Welcome to the Deep Dive.

Today, we are taking a really targeted look at the pharmacotherapeutics of sleep disorders.

This is absolutely crucial stuff for advanced practice providers.

It really is.

And it's not just about feeling rested, is it?

I mean, the scope of poor sleep, it's practically a global economic crisis.

Exactly.

Those numbers are just huge.

Yeah.

I mean, you look at the RAND Corporation report, they estimated the annual economic loss for the U .S.

alone just from insufficient sleep could be up to $411 billion.

Wow.

$411 billion.

Billion, yeah.

So that's why, you know, proper targeted pharmacological intervention isn't just a nice to have, it's essential.

That figure alone just shows we need to go way beyond, like, simple over -the -counter things.

Absolutely.

So our mission today is to take the advanced practice literature, the chapter specifically, and really distill the key pharmacology for the big three, insomnia, restless leg syndrome, or RLS -EBIDID and narcolepsy.

And the foundational principle, really the key thing you have to remember,

is that drug therapy isn't right for everything.

Conditions like primary snoring or obstructive sleep apnea.

Pharmacologic therapy isn't appropriate there.

You have to diagnose the specific disorder first.

Right.

First things first.

Okay, let's unpack this then.

Starting with insomnia, that's the most common one we see, right?

By far.

And when we treat insomnia, the goal isn't just getting the patient to sleep.

It's more complex.

It's dual, exactly.

You need to improve both the sleep quality and quantity, and you've got to address the daytime impairment that the poor sleep is causing.

Makes sense.

So the drugs.

Traditionally, we start with the hypnotics.

That's the main category, yes.

And within that, you've got the older benzodiazepines, the BZDs, and then the newer benzodiazepine receptor agonists, or BZRAs.

Understanding the difference is pretty critical.

Okay, let's start with the BZDs.

Still used, of course.

We know they work by enhancing GABA effects in the CNS.

But how does that lack of specific targeting, that receptor non -selectivity, lead to that classic morning hangover we always worry about?

Well, it really comes down to their broad action.

BZDs are synthetic, sedative hypnotics.

They boost GABA, which is inhibitory, slows things down.

But they act widely,

hitting multiple GABA -E receptor subunits, alpha 1, 2, and 3.

So while they give you the sleepiness you want, that's the alpha 1 effect.

They also bring along unwanted effects, like anxiolysis and muscle relaxation from the other subunits.

And it's those effects, often combined with a pretty long half -life, that cause the rebound insomnia sometimes, and definitely that cognitive hangover the next day.

So that non -specificity and the duration of action are the main clinical challenges.

How do we actually pick the right BZD for a specific patient's complaint, then?

Is it just about half -life?

Pretty much.

You have to match the drug's half -life to the patient's specific problem.

So say someone struggles mainly with sleep maintenance.

They fall asleep, okay, but keep waking up all night.

Then intermediate acting agents, like Tamazepam, or perhaps Eftazolam, are often a good choice.

It's always this balancing act, finding the duration you need without causing that residual sedation, that hangover.

So if non -specificity is the big problem with BZDs, how did the BZRAs, like Azulpidem, Xyloplon,

how did they try to fix that pharmacologically?

They tackled it head -on with selectivity.

That's the key difference.

BZRAs are often called non -benzodiazepines because chemically they look different.

Right, structurally different.

Yeah, but they still act on the GABA system.

The crucial part is they are selective for just the alpha -1 subunit.

Ah, the sleepiness subunit.

Exactly, the one that primarily governs sedation.

So the idea, the intent, was to induce sleepiness without those profound anti -anxiety or muscle relaxation effects you get with the broader BZDs.

But even with that improved selectivity, these drugs carry some really unique and, frankly, quite serious risks.

Tell us about the big one, the critical adverse event associated with this BZRA class.

Yeah, this one's important.

It's the complex sleep -related behaviors.

Well, they're genuinely concerning.

We're talking about patients doing things while asleep, sleepwalking, making food, even driving a car with absolutely no memory of it afterwards.

Sleep driving, that's terrifying.

It is.

And it means providers have to be incredibly cautious with dosing.

Take Zulbrim, Ambien, for example.

The FDA actually issued guidance back in 2013 -2014 specifically requiring lower starting doses for women.

Oh, right, I remember that.

Five milligrams for women.

Exactly.

Five milligrams for females versus 10 milligrams for males.

It's because of known pharmacokinetic differences, women tend to have higher drug levels the next morning, increasing the risk.

And we should also mention Azopaclone, Lunesta.

Even at its max dose, the impairment lasts a long time.

That's a really important point.

The maximum three milligram dose of Azopaclone, it's associated with measurable performance impairment for over 11 hours.

11 hours.

Yeah, so it really highlights why you, as the practitioner, have to be aware of these carryover effects, even with the supposedly more targeted BZRA class.

Okay, so moving beyond the GABA system entirely,

let's look at the newer classes.

These target wakefulness, which is a different approach.

Tell us about the orexin receptor antagonists suverexant, lemorexant.

Yeah, this is a really fascinating shift in strategy.

Instead of sort of forcing sedation via GABA, you're inhibiting wakefulness.

The orexin system, sometimes called the Hippocretin system,

its natural job is to promote wakefulness.

So these drugs, the Doraaz, dual orexin receptor antagonists - Floraaz, got it.

They work by blocking that wakefulness signal.

And by doing that, they help facilitate the natural onset and maintenance of sleep.

It's a more subtle approach, perhaps.

But that specific action, blocking wakefulness, creates a very clear contraindication, doesn't it?

Absolutely.

Direct consequence.

Because they inhibit the system that keeps you awake, they are strictly contraindicated in patients diagnosed with narcolepsy.

Which is defined by excessive daytime sleepiness.

Makes perfect sense.

Exactly.

You wouldn't want to inhibit wakefulness further in those patients.

Okay.

And then finally, in the insomnia space, there's Rammelten -Roseram.

Given how many drugs target GABA, what's the advantage of moving completely outside that system, like Rammelten does?

Well, Rammelten works differently.

It stimulates the MP1 and MT2 melatonin receptors located in the suprachiasmatic nucleus of the brain.

The body's clock.

Basically, yeah.

It mimics the natural signal of darkness, which helps shorten the time it takes to fall asleep, what we call sleep onset latency.

The big advantage.

It does this without messing with GABA, or dopamine, or serotonin.

So it offers a potentially different, maybe cleaner safety profile for some patients.

Interesting.

Any key clinical pearls for Rammelten?

Yes.

One very important one.

The standard 8 -milligram dose must be avoided with high -fat meals.

Ah, food interaction.

Big time.

A high -fat meal can dramatically increase the drug's exposure, the AUC, and significantly raise the risk of side effects.

So take it on an empty stomach.

Good to know.

Okay, so let's try to summarize the overall treatment strategy for insomnia.

You're the advanced practitioner.

You have this menu of options, BZDs, BZRAs, DORAs, Rammelten.

How do you choose?

Right.

So the clinical algorithm, like you see in figure 41 .1 in the text, generally points to first -line therapy involving matching an agent from the BZD, BZRA, or Rammelten in classes to the specific sleep defect.

Is it trouble falling asleep or trouble staying asleep?

Matching the drug profile to the patient's problem.

Precisely.

And something else really important to remember, especially for certain patient populations.

Doxilamin succinate, which is just an antihistamine, right?

It's actually the only agent that's approved for unrestricted use to manage sleep issues during pregnancy.

That's a critical point for practice.

Okay, and what if those first -line agents don't work or aren't appropriate?

Then you move to second -line options.

Often this involves looking at certain sedating antidepressants like trazodone or metazapine.

These can be particularly helpful if the patient also has comorbid depression or anxiety, tackling both issues at once.

Got it.

Okay, let's shift gears now.

Restless leg syndrome,

or RLS will aid.

This is that intense, almost creepy crawly urge to move the legs, right?

Usually worse in the evening or at night.

And temporarily relieved by activity, like walking around.

That's the classic picture, yes.

As described in box 41 .6.

So pathologically, what are we trying to treat here?

What's the root cause?

Well, the pathophysiology seems linked to a couple of things.

Low iron levels are problems with iron transport within the central nervous system and also underlying dopaminergic abnormalities.

So the goal with drug therapy is purely symptom management.

There's no cure.

Right.

And importantly, you first have to decide if the patient actually needs daily treatment.

If symptoms are just intermittent, maybe occasional, you often want to defer chronic therapy, if possible, precisely to avoid the long -term risks associated with the medication.

Okay.

So for those who do need daily treatment, dopamine agonists like Primapexol and Rotagatine are often the first choice, but they come with this really significant concern.

Augmentation.

What exactly is augmentation?

It sounds worse than just tolerance.

It is worse than tolerance.

Augmentation is a major, major clinical hurdle with these dopamine agents.

It's when the drug, which initially helped the RLS way to eat symptoms,

paradoxically starts to make them worse.

The symptoms might start earlier in the day, become more intense, or even spread to the arms or trunk.

Wow.

So the treatment makes the disease worse.

In essence, yes.

And it's a distinct phenomenon from tolerance where the drug just becomes less effective over time.

Augmentation can happen surprisingly quickly too, sometimes within just 10 weeks or so of starting therapy.

So you have to be really cautious about long -term use.

Okay.

So to sidestep that risk, providers might look towards anticonvulsants instead, but there's a specific nuance here with gabapentin, right?

Standard gabapentin versus the approved agent.

Yes, that's key.

The specifically approved agent for RLS we get is gabapentin enicarbol, brand name Horazin.

Usually dosed at 600 milligrams once daily, typically in the evening.

And how is that different from regular gabapentin?

The difference is the formulation.

Gabapentin enicarbol is a prodrug.

It's designed to be absorbed differently and provide a sustained release, prolonged drug profile over time.

Ah, so it covers the whole night better.

Exactly.

That's essential for controlling those nighttime RLS wet symptoms.

Standard immediate release gabapentin just can't reliably provide that sustained coverage, which is why using it for RLS wet is considered off -label.

Makes sense.

And we absolutely cannot forget the iron connection here.

Oh, definitely not.

Iron replacement is vital with indicated.

You need to check morning ferritin and iron levels, specifically transfer and saturation.

If transfer and saturation is low, the text mentions a cutoff, but generally if iron stores are low and saturation is less than say 45 % or even 20%, depending on guidelines, replacement is often needed.

And how is that done?

Typically ferrous sulfate, 325 milligrams, which provides 65 milligrams of elemental iron taken twice daily.

And crucially, you pair it with vitamin C, maybe a hundred milligrams twice daily to enhance absorption.

Monitor those iron levels.

Okay.

Before we leave RLS web, we really need to pause and emphasize the geriatric consideration.

These sedative drugs are so often misused in older adults.

Absolutely critical point.

This is a non -negotiable clinical pearl for any advanced practitioner.

The beers criteria, which guides safe prescribing in older adults,

strongly advises avoiding first -generation antihistamines like diphenhydramine and also

benzodiazepines, particularly short and intermediate acting ones in this population.

Why the strong warning?

Because the risk of adverse effects is significantly higher.

We're talking increased risk of delirium, cognitive decline, confusion, and very importantly falls, which can be devastating for older adults.

So extreme caution is mandatory with any hypnotic or sedating agent in this age group.

Duly noted.

Okay.

Finally, let's tackle narcolepsy.

This is characterized by that tetrad, excessive daytime sleepiness, EDS, cataplexy, hallucinations, sleep paralysis.

Right.

The primary goal here is careful titration of medication to achieve the optimal level of stimulation, allowing the person to function as normally as possible during the day.

And the first line agents are often the wake promoting ones.

Yes.

Typically modafinil and its artinantiomer are modafinil.

Their exact mechanism isn't fully understood, surprisingly.

Yeah.

It's thought they might attenuate the central alpha one adralergic system, perhaps influence dopamine signaling, but it's complex.

Clinically though, they work and they have the advantage of a long half -life around 15 hours, which helps provide coverage throughout the day.

Okay.

Then we get into some really specialized, unique agents like sodium oxybet.

All right.

Sodium oxybet is interesting.

It actually contains a component of GHB.

It's unique because it's approved to treat both the excessive daytime sleepiness and cataplexy and narcolepsy.

But it comes with restrictions.

Big restrictions.

Because of its potential for abuse, it's a schedule three controlled substance.

Prescribing and dispensing it requires participation in a strict risk evaluation and mitigation strategy program, a REMES program.

So there are significant hurdles to its use.

Okay.

Now let's talk about what feels like a potential game changer.

Pitolacin.

It's a histamine H3 antagonist inverse agonist.

Why is its status as a non -scheduled medication such a big deal for treating these chronic conditions?

Pitolacin or Wacix is genuinely significant for exactly that reason.

It's the first drug approved for narcolepsy that is not a scheduled medication.

That's huge administratively.

It's huge.

It immediately removes the burden of needing a REMES program, simplifies prescribing, and likely reduces the perceived risk profile for both providers and patients dealing with a long -term condition.

And how does it work?

H3 antagonism.

Right.

It blocks the H3 histamine auto receptor.

By blocking this receptor, which normally inhibits histamine release, pitolacin effectively increases the release of histamine in the brain.

And histamine is a key wake -promoting neurotransmitter.

It also indirectly boosts other wakefulness signals like acetylcholine and dopamine.

Fascinating mechanism.

And then lastly, there's Solriumfetal.

Yes.

Solriumfetal, brand name, Sunosi.

This one is a dopamine norepinephrine reuptake inhibitor, a DNRI.

It's indicated specifically for excessive daytime sleepiness in narcolepsy.

And also obstructive sleep apnea.

Is it scheduled?

It is scheduled at schedule four, but importantly, it does not require a REMES program.

Another plus is that it undergoes minimal metabolism.

It's mostly excreted unchanged in the urine, which can simplify things regarding drug interactions.

Okay.

Wow.

That really gives us a clear roadmap through the pharmacology of these three very distinct, very complex sleep disorders.

Yeah.

And if we try to synthesize it down, insomnia treatment really revolves around targeting either the inhibitory GABA system or modulating the stimulatory orexin or melatonin systems.

Right.

RLS -WED focuses on addressing underlying dopaminergic issues and absolutely requires careful attention to iron status and the risk of augmentation.

And then narcolepsy relies heavily on various wake promoting agents,

with, as we discussed, a really interesting trend towards newer, non -scheduled agents targeting specific receptors like histamine H3.

The essential takeaway for advanced practice, though, across all of these is individualizing therapy based on the patient's specific symptoms, sleep onset versus maintenance, presence of cataplexy, and their comorbidities.

That personalization is so key, isn't it?

Especially when you weigh the potential side effects, which brings us to a final thought for you, the listener.

Given these complex, sometimes dangerous side effects, we've discussed things like sleep driving with BZRAS or that risk of augmentation in RLS -WED with dopamine agonists.

How might the development of these newer, non -scheduled, perhaps more targeted agents like patoliscent, how might that fundamentally shift the initial treatment algorithms we use for these chronic disorders over the next, say, decade?

Something definitely worth mulling over.

That's a really provocative question, and one I think we'll see playing out in clinical practice.

Indeed.

Well, thank you for joining us for this deep dive into the pharmacotherapeutics of sleep disorders.

Thank you.