Chapter 18: Hypertension – Drug Treatment & Clinical Guidelines

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Welcome to the Deep Dive.

Today, we're tackling a really fundamental topic from advanced

pharmacotherapeutics, hypertension.

Right.

We're digging into Chapter 18 of Pharmacotherapeutics for Advanced Practice, our goal to give you the absolute must -know pharmacology ready for you to use.

And it's so critical.

Hypertension, I mean, they call it the silent tiller for a reason, affects nearly, what, 46 % of US adults.

Wow.

Yeah, it's huge.

And it's driving strokes, heart disease, kidney disease.

The numbers are, frankly, alarming.

The death rate linked to HTN jumped over 25 % between 2007 and 2017.

That's staggering.

It is.

So today, we're zeroing in on core pharmacology, how we diagnose it, the goals, how the drugs work, and maybe most importantly, the things you absolutely cannot do, the contraindications.

Exactly.

We'll walk through the major drug classes, focusing on those key details for safety and getting results for patients.

Let's start at the beginning.

Getting that diagnosis correct.

You really can't treat hypertension well if you haven't diagnosed it properly.

And it's basic, but worth repeating.

You never, ever diagnose HTN from just one high reading.

Never.

It takes at least two separate readings.

And they need to be at least a week apart.

Right, correct.

At least a week apart.

And the technique itself is crucial.

You need the patient seated,

relaxed for five minutes beforehand.

Back supported, feet flat on the floor.

Arms supported, right at heart level.

All those little things matter.

And we have to think about what could skew the reading to.

Absolutely.

You need to tell patients, avoid caffeine, nicotine, even those over -the -counter decongestants with audrenergic effects for like 30 to 60 minutes before.

Because if that baseline reading is off, your whole treatment approach could be wrong from the start.

Exactly.

Get the baseline right.

Now, the definitions and goals have changed over time, which can be confusing.

The source talks about the JNC8 goals.

Yeah, JNC8 was a bit more, let's say lenient, like accepting 100 to 50 over 90 for folks over 60.

But then the 2017 ACC AHA guidelines came along and tightened things up considerably.

They really did.

Focused much more on risk.

So let's break down those ACSA categories.

Normal is still easy.

Less than 120 over 80.

Elevated is that 120 to 129 systolic range.

But diastolic is still under 80.

Got it.

Then stage one hypertension is 130 to 90 or higher systolic or 90 or higher diastolic.

So with these stricter categories, what's the typical target BP we're shooting for?

Well, for stage two, and definitely someone has diabetes or chronic kidney disease, the general goal now is pushing below 130 over 80.

Right.

Lower targets for higher risk.

Precisely.

And before we get into the drugs, just a quick reminder on causes.

About 95 % of cases are primary or essential hypertension.

We don't know the exact cause, but it involves genetics, environment, maybe an overactive RAS system.

And the other 5%.

That's secondary hypertension.

There, you can often find a specific cause, things like chronic kidney disease, runovascular issues, sleep apnea, or even medications like NSAIDs or birth control pills.

Okay, let's talk meds.

If the pressure is high, gyretics are often where we start.

The initial mechanism seems pretty straightforward, right?

Get rid of fluid.

Yeah.

Initially, it's all about reducing plasma volume, which lowers stroke volume, then cardiac output drops.

Makes sense.

But the chapter mentions a shift with long -term use.

It does, and it's quite interesting.

Over months of chronic therapy, that initial volume depletion effect becomes less important.

The main benefit actually transitions to a decrease in peripheral vascular resistance.

The blood vessels themselves relax more.

So it's not just plumbing after all.

Not entirely, no.

Let's focus on the workhorses.

Thiazides.

How do they work?

Thiazides and the thiazide -like diuretics, they block sodium and chloride from being reabsorbed back into the blood, specifically in the distal convoluted tubule of the kidney.

More salt and water leave in the urine.

Okay.

But there are some big warnings, especially around kidney function.

Huge warnings.

First off, they just don't work well if the patient's creatinine clearance, the CRCL, is less than 30 lm in.

So limited use in significant kidney disease.

Right.

And they're absolutely contraindicated if the patient has anuria not making urine, or if they have a known allergy to sulfonamide drugs, because thiazides are sulfa derivatives.

What about gout?

Good point.

Thiazides can increase uric acid levels, cause hyperuricemia.

So if a patient has a history of gout, you need to be cautious, as it could trigger flares.

And the chapter had a pearl about dosing HCTZ, hydrochlorothiazide.

Ah, yes.

Dosing above 25 mg usually doesn't give you much more blood pressure lowering effect.

But it does increase side effects.

Exactly.

You mainly get more side effects, especially hypokalemia low potassium.

That happens in maybe 15 -20 % of patients, even on low doses.

Plus, compared to some other classes like ACE inhibitors or ARBs, thiazides have a slightly higher risk of leading to new onset diabetes.

Okay.

What about loop diuretics then?

When do we use those?

Loops are sort of the heavy hitters reserved for situations where you need more potent diuresis.

Think patients with significant chronic renal insufficiency, say a serum creatinine over 2 .5, or those with heart failure who are volume overloaded.

And they come with a unique, serious side effect risk.

Yes.

Auto toxicity.

Hearing loss.

It's more common if you give high doses, push IV doses too quickly, or if the patient already has severe kidney impairment.

Ethicranic acid seems to carry the highest risk among the loops for this.

Good to know.

Lastly in this group, potassium sparing diuretics and aldosterone antagonists.

Right.

These work later in the tubule, interfering with sodium reabsorption in a way that decreases potassium secretion so they help hold on to potassium.

And the aldosterone antagonists, like spironolactone.

They specifically block the effects of aldosterone, a hormone that promotes sodium and water retention.

Spironolactone, uplarinine, they compete for that receptor.

Where do these really shine?

They have a huge role in heart failure management.

The O 'Riol's trial, for instance, showed major benefits for spironolactone and severe heart failure.

But you absolutely must watch out for hyperkalemia hypotassium.

Especially if combined with?

Especially if the patient is also taking an ACE inhibitor, an ARB, NSAIDs, or potassium supplements.

That combination significantly increases the risk.

And spironolactone specifically has those unique hormonal side effects.

Gynecomastia in men, hirsutism, or menstrual issues in women.

Right.

Moving on from diuretics to the drugs that target the body's core pressure system.

The renin -angiotensin -aldosterone system, or RAAS.

These are really key, especially for patients with diabetes or kidney disease.

Let's start with the ACE inhibitors.

The ACE inhibitors, yeah.

Their mechanizer is, well, it's pretty elegant, actually.

They do two main things.

First, they block the enzyme angiotensin -converting enzyme that converts angiotensin the first to angiotensin the second.

And angiotensin the second is the potent vasoconstrictor.

Most potent one your body makes, yeah.

So blocking its production lowers blood pressure.

Second,

ACE inhibitors also prevent the breakdown of bradykinin.

Bradykinin, that causes vasodilation.

It does.

Partly by stimulating prostaglandin release.

So you get less vasoconstriction and more vasodilation.

It's a powerful combo.

But this power comes with some serious warnings.

What are the absolute contraindications for ACE inhibitors?

Three big ones you cannot forget.

One, bilateral renal artery stenosis narrowing of the both kidneys.

Two, pregnancy.

They are absolutely teratogenic.

Cannot use them in pregnancy.

Never.

And three, a history of angioedema, that swelling reaction, especially if it occurred with the previous ACE inhibitor.

And it's worth noting that risk of angioedema is significantly higher, like two to four times higher in African -American patients.

Okay.

What about common side effects?

The most famous one is that persistent dry cough that's linked to the bradykin effect.

Also hyperkalemia, like we discussed with potassium -sparing diuretics, and sometimes a rise in serum creatinine.

Right.

You mentioned the creatinine might go up.

How much of a rise is okay when starting an ACE?

A rise of up to 30 % from the baseline level is generally considered acceptable.

It often reflects changes in kidney blood flow that aren't necessarily harmful long -term, but you have to monitor.

How soon?

You need to check serum creatinine and potassium levels within about one to two weeks of starting the drug or increasing the dose.

Crucial safety check.

Okay.

Now, if that cough is just too much for a patient.

Then you often move to an ARB, an angiotensin II receptor blocker.

How are they different?

They work one step down the cascade.

Instead of blocking the production of angiotensin II, they block angiotensin II from actually binding to its receptor, the AT1 receptor.

So you still block the vasoconstriction and aldosterone release, but without affecting bradykinin levels as much.

Which means no cough, usually.

Much, much lower risk of cough.

That's their main advantage over ACEs for tolerability, but they share the same major contraindications, pregnancy and bilateral renal artery stenosis.

Still teratogenic.

And what about using ACEs and ARBs together or with the other RAAS drug, alloscarin?

Ah, yes.

The direct renin inhibitor, alloscarin.

It blocks the very first step, the conversion of angiotensinogen to angiotensin I.

But combining any of these RAAS drugs, ACE plus ARB, ACE plus alloscarin, ARB plus alloscarin is a definite no -no.

Why is that?

The evidence, particularly from trials like Altitude, showed that combination therapy, especially in patients with diabetes, increased adverse events like hyperkalemia and kidney problems without providing any additional cardiovascular benefit.

So you just don't do it.

Pick one RAAS agent, if indicated.

Okay, let's shift gears now to drugs that affect the sympathetic nervous system and smooth muscle.

Beta blockers first.

How do they lower blood pressure?

Beta blockers work primarily by blocking beta -entronergic receptors.

This happens both centrally, reducing sympathetic outflow from the brain, and peripherally on the heart itself.

Blocking beta -1 receptors on the heart decreases heart rate and contractility, which lowers cardiac output.

And there are different types, right?

Selective versus non -selective.

Exactly.

That's a key distinction.

We have cardio -selective agents, like metaprol or bisoprolol.

They preferentially block beta -1 receptors, which are mostly in the heart.

Making them safer for?

Safer for patients who also have lung conditions like asthma or COPD, where blocking beta -2 receptors in the lungs could cause bronchospasm.

Then you have the non -selective ones that block both beta -1 and beta -2.

And some have added effects.

Yes, some newer ones like carvetolol and lebetolol also block alpha -1 receptors.

This adds a vasodilating effect, which often makes them more effective at lowering blood pressure compared to beta blockade alone.

Now this class has a really critical counseling point regarding stopping the medication.

Absolutely vital.

You must tell patients never to stop taking their beta blocker abruptly.

Why not?

Because the body upregulates beta receptors during chronic blockade.

Stopping suddenly leaves all those receptors exposed to circulating catecholamines, which can cause a severe withdrawal reaction on stable angina, heart attack, even sudden death, especially if they have underlying coronary artery disease.

So how should they be stopped?

You have to taper the dose down gradually, usually over about 14 days.

Slow and steady.

Okay.

Other side effects to watch for?

Fatigue is common, sometimes depression.

And importantly, in patients with diabetes, beta blockers can mask many of the warning symptoms of hypoglycemia, like tremor or palpitations.

The only symptom they don't typically mask is sweating.

So that's critical education for diabetic patients.

Good point.

Okay, let's move to calcium channel blockers.

CCBs, how do they work?

CCBs work by blocking the entry of calcium into smooth muscle cells, particularly in the blood vessel walls, and also into cardiac muscle cells.

Calcium is needed for muscle contraction, so blocking its entry leads to muscle relaxation.

Resulting in vasodilation.

Right.

Vasodilation, which lowers peripheral resistance and blood pressure.

They are very effective agents, often work well as monotherapy, and are noted as being particularly effective first -line choices in black patients.

Like beta blockers, CCBs are all the same.

There are two main groups.

Yes, the dihydropyridines and the non -dihydropyridines.

Very different profiles.

Let's start with the non -dihydropyridines.

Which ones are those?

That's varapamil and diltiasm.

Besides vasodilation, they have significant effects on the heart's electrical conduction system.

They slow down the heart rate and decrease conduction through the AV node.

Which means they have specific contraindications.

Definitely.

You avoid them in patients with pre -existing heart block because they can

And also in patients with systolic heart failure, meaning a reduced ejection fraction.

Typically less than 40 % because their negative effect on contractility can worsen failure.

And drug interactions.

Big potential there.

Varapamil and diltiasm are potent inhibitors of the CYKE3A4 enzyme system in the liver, so they can significantly increase levels of many other drugs metabolized that way.

Always check for interactions.

Okay, what about the other group?

The dihydropyridines.

These are drugs like amlodipine, nephetapine, philodipine.

They are much more potent vasodilators and have less effect on heart rate and conduction compared to the non -dihydropyridines.

So their side effects reflect that vasodilation.

Exactly.

Things like headache, dizziness, flushing, palpitations.

Because the heart might beat faster initially to compensate for the drop in pressure and peripheral edema, especially ankle swelling.

It's very common with dihydropyridines.

And there's a warning about one specific dihydropyridine.

Yes, short -acting nephetapine.

The immediate -release capsules.

They cause rapid drops in blood pressure, which can trigger reflex tachycardia and potentially increase ischemic risk.

They really shouldn't be used for managing chronic essential hypertension.

Use the long -acting formulations instead.

So we've covered the main drug classes.

Now how do you put it all together for a specific patient?

The guidelines give us a framework.

Right.

And one key point is about starting therapy.

If someone's blood pressure is way above goal, say more than 20 over 10 mmHg higher, or if they're already in stage 2 HDM.

Then the recommendation is actually to start with two antihypertensive agents from different classes right from the beginning.

Don't just start one and wait.

Okay.

And the initial choice often depends on ethnicity, according to the guidelines referenced.

Generally, yes.

For non -black patients, the first -line options are typically a thiazide diuretic, a CCB, an ACE inhibitor, or an ARB.

You have choices.

But for black patients?

For black patients, the recommendation leans strongly towards starting with either a thiazide diuretic or a CCB.

ACEs and ARBs can be used, but often aren't as effective as monotherapy in this population, possibly due to lower baseline renin levels.

But there's one major exception to that race -based approach, right?

Yeah.

Regarding kidney disease.

Absolutely critical exception.

For any adult patient with chronic kidney disease, CKD, regardless of their race or age, an ACE inhibitor or an ARB is recommended as part of the regimen.

Why specifically those?

Because they have demonstrated specific kidney protective benefits, slowing the progression of CKD beyond just lowering blood pressure.

It's about improving renal outcomes.

And if you're choosing a diuretic, any preference?

The evidence, particularly from large trials, tends to favor

over hydrochlorothiazide HZTZ.

It has a longer duration of action and potentially stronger data for reducing cardiovascular events.

Let's talk a bit more about these special populations.

You mentioned African -American patients.

Yes.

Unfortunately, they have a higher incidence of hypertension and also suffer more severe complications like stroke and kidney failure.

Physiologically, as we noted, they often have lower renin levels and maybe higher intracellular calcium, which helps explain why phyocides and CCBs tend to work well initially.

What about older adults, say over 65?

Geriatric patients often need a gentler approach.

Start low, go slow with dose titration.

They can be more sensitive to volume depletion from diuretics and sympathetic inhibition from drugs like beta blockers, increasing the risk of orthostatic hypotension and falls.

So good initial choices for them.

Diuretics, especially thiazides for isolated systolic hypertension or long -acting CCBs, are often very effective in well -tolerated first -line options in older adults.

And then there's pregnancy.

This is a huge area of concern.

Huge.

The absolute number one thing to remember is that ACE inhibitors, ARBs and direct renin inhibitors like alloscarin are all strictly contraindicated.

They are teratogenic, can cause major birth defects or fetal death.

So what can be used safely?

Historically, methyl dopa has been a preferred agent, especially if HTN is diagnosed during pregnancy.

Lebdolol, that combined alpha -beta blocker, is also commonly used and often preferred later in pregnancy.

Nephthatepine is another option.

But management should always involve specialist consultation.

Okay.

And one last distinction.

Hypertensive crisis,

urgency versus emergency.

Right.

It's all about end -organ damage.

Hypertensive urgency is very high blood pressure, but crucially, no signs of acute damage to organs like the brain, heart or kidneys.

This can usually be managed more slowly, often outpatient, frequently by just restarting the patient's missed medications.

And hypertensive emergency.

That's the dangerous one.

Same severely high BP, but with evidence of acute ongoing end -organ damage like stroke symptoms, chest pain suggesting MI, acute kidney injury, papildema.

This requires immediate hospitalization, usually ICU admission, and controlled gradual lowering of blood pressure with IV medication.

Controlled and gradual being key, right?

Not dropping it too fast.

Absolutely.

Lowering BP too rapidly in an emergency can actually worsen perfusion to vital organs and cause more harm.

It needs careful monitored reduction.

So treatment is started, maybe adjusted.

The work isn't over, is it?

Monitoring is ongoing.

Constantly.

You need to measure BP at every single visit.

And you need to evaluate progress monthly until that BP goal is consistently achieved.

And specific lab monitoring for certain drugs.

Yes, especially for those high -risk drugs we talked about.

When starting or titrating diuretics or any RAAS inhibitor ACEs, ARBs, you need to recheck serum creatinine and potassium within about 7 to 10 days.

That's a critical safety window.

This really brings us to what might be the hardest part.

Patient education and adherence.

It often is.

Because hypertension is usually asymptomatic, patients don't feel sick.

So convincing them to take medication every day, possibly for life, for a condition they can't feel, is a major challenge.

We have to stress it's a lifelong commitment.

Lifelong.

And we have to empower them with lifestyle changes too.

These aren't just add -ons, they're foundational.

The impact can be significant, right?

Huge.

Weight loss alone, every 10 kilogram lost, can lower systolic BP by 5 to 20 points.

Adopting the DIAHC diet can lower it by up to 11 points.

Reducing sodium intake to less than 2 .4 grams daily, getting regular physical activity.

It all adds up.

And we need to be upfront about side effects and the treatment process.

Absolutely.

Tell patients that finding the right medication or combination might take some trial and error.

Prepare them for potential side effects, encourage them to report them, and reassure them that there are usually alternatives if one drug doesn't suit them.

Assessing adherence, are they actually taking the meds?

Needs to happen at every visit.

Okay, so if we had to boil down the absolute critical takeaways from this deep dive.

Right.

Those key contraindications again.

Right.

Three non -negotiables.

Number one, ACE inhibitors, ARBs, renin inhibitors, absolutely out if the patient is pregnant or could become pregnant.

Number two, phyazide diuretics generally avoid if the CRCL is under 30 or if the patient has active gout.

Number three, non -dihydropyridine, CCBs, verapamil, and diltiasm, avoid in patients with systolic heart failure or significant heart block.

Got it.

So here's the final thought we want to leave you with, reflecting on everything in this chapter.

We have incredibly powerful pharmacologic tools now to manage hypertension.

But perhaps the greatest challenge isn't just knowing the mechanisms or the guidelines.

It's bridging the gap between that knowledge and successful long -term patient adherence for a disease that doesn't shout until it's often too late.

Your ability to educate, build trust, and monitor consistently might just be your most potent therapeutic intervention.

We really hope this deep dive has been helpful.

A warm thank you from the Last Minute Lecture Team for joining us.

Thanks for tuning in.

We'll catch you next time.