Chapter 49: Anti-Inflammatory & Antigout Drugs

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If you're looking for a way to get up to speed on complex medical topics fast without slogging through dense text,

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Today we're jumping straight into anti -inflammatory and anti -gout drugs.

We're going to break down the key info from the source material that guides Canadian practice.

This is a really important one.

We're talking about inflammation,

that protective response, pain, swelling,

fever.

The body trying to fix something.

Exactly.

But the drugs we use, especially the anti -sides, I mean, they're everywhere.

Lots are over the counter.

Super common.

But they carry some major risks that people often underestimate.

GI bleeds, kidney problems.

It's serious stuff.

So our goal today is to make sure you really understand those risks.

Absolutely.

So let's start at the beginning.

We need to understand how inflammation actually works, right?

What's the engine driving it?

Okay.

So imagine some tissue gets damaged.

The first thing that happens is phospholipids in the cell membranes release this fatty acid called arachidonic acid.

Okay.

Arachidonic acid, that's the trigger.

That's the initial spark.

Yeah.

Right.

Think of it like lighting a fuse.

And from there, the pathway splits, basically goes in two main directions.

Two branches.

What are they?

So one branch uses enzymes called lipoxogenases.

This makes leukotrienes.

Leukotrienes.

What do they do?

They're big players in things like bronchospasm,

you know, asthma -like effects, vaginal constriction, making blood vessels leaky and causing edema, swelling, basically.

Okay.

So that's one path.

What's the other?

The other path, and this is probably the one we think about more with pain relief, uses the cyclooxygenase enzymes or COX enzymes.

COX enzymes.

Heard of those.

Right.

They take that arachidonic acid and turn it into prostaglandins.

And these guys are what cause vasodilation, make nerves more sensitive to pain, hyperalgesia, and trigger fever.

Specifically, PGE2 acting on the hypothalamus.

Got it.

So the drugs must target these COX enzymes then.

Exactly.

That's the main strategy.

But here's the crucial bit.

There are different types of COX enzymes and they do different things.

Ah, okay.

So it's not just one target.

Yeah.

Nope.

You've got Keox1.

Think of Keox1 as the housekeeping enzyme.

It's generally beneficial.

It does important stuff like protecting your stomach line and keeping it intact and helping platelets work properly.

Okay.

So we probably don't want to block Keox1 too much then.

Ideally, no.

Then there's Keox2.

This one gets switched on or induced mainly at the site of injury or inflammation.

It's the one churning out the prostaglandins that cause the pain and swelling we want to stop.

So Keox1 is protective.

Keox2 is inflammatory.

That's the simplified view, yeah.

And it explains a lot about NSAID side effects.

The older drugs, the traditional NSAIDs, they just blocked both Keox1 and Keox2.

Ah.

So they stopped the inflammation but also messed with the protective stuff.

Precisely.

Which is why things like stomach ulcers and bleeding were such huge problems.

So the thinking was, let's create drugs that only block Keox2, the selective Keox2 inhibitors like Celecoxib.

To get the benefit without the major GI side effect.

That's the theory, yes.

Hit the inflammation and spare the stomach lining.

We'll come back to how well that worked out.

Hashtag nonsteroidal anti -inflammatory drugs, NSAIDs.

All right.

Let's talk about the drugs themselves, the NSAIDs.

Nonsteroidal anti -inflammatory drugs.

Huge group, right?

You said over 30 available.

Yeah.

That's a really diverse chemical group.

But they all generally aim for those analgesic anti -inflammatory and antipyretic fever -reducing effects.

Think headaches, arthritis, period pain, gout flares.

The workhorses.

Where do we start?

Aspirin.

You gotta start with aspirin.

Acetyl salicylic acid, ASA, that's the original, the prototype.

And it's actually unique in how it works compared to most other NSAIDs.

How so?

It's an irreversible inhibitor of COX -1 inside platelets.

Irreversible.

Okay, what does that mean practically?

It means that once aspirin hits that COX -1 enzyme in a platelet, that enzyme is knocked out for the entire lifespan of that platelet.

It can't make thrombox -NH2 anymore, which is needed for clotting.

And platelets live for about a week?

Roughly 7 to 10 days, yeah.

So even a low dose of aspirin has this lasting anti -platelet effect.

That's why it's so important for secondary prevention of heart attacks and strokes for people who've already had one.

But the source specifically says not for primary prevention, right?

Not for people who haven't had an event.

Correct.

The bleeding risk outweighs the benefit in that population, generally.

Okay, moving on.

We have other classes.

Acetic acid derivatives.

It includes endomethacin, but the one to really flag is Ketrolac, brand name, tortidoy.

Ketrolac, why flag that one?

Because its pain relief is incredibly potent.

It's often compared to morphine used for moderate to severe acute pain, like post -op pain.

Wow.

But there's a catch, I assume.

Big catch.

Because of serious risks, especially to the kidneys and the GI tract, its use is strictly limited.

We're talking 5 to 7 days maximum.

5 to 7 days, that's it.

It doesn't matter if the patient is young, healthy.

It doesn't matter.

The risk profile is just too high for longer duration.

It's a short -term fix only.

Okay.

Good to know.

What else?

Then you've got the propionic acid derivatives.

There's ibuprofen is the big one here, the prototype, and naproxen is probably the second most commonly used NSAID overall.

Right.

Ibuprofen, naproxen, very familiar.

And finally, those selective CoX2 inhibitors we mentioned.

The main one left on the market in Canada is Celecoxib, Celebrex.

Only one left.

What happened to the others?

Others like Rofocoxib, Vioxx, and Valdicoxib were pulled.

Big controversy.

Turns out, blocking only CoX2 actually increased the risk of cardiovascular events.

Heart attacks, strokes.

Oh, wow.

So trying to avoid the GI risk led to a heart risk.

That's what the data showed, unfortunately.

Which brings us right back to the core dangers of all NSAIDs.

We need to spell these out clearly.

Okay.

The triple threat.

You called it earlier.

Let's hear it.

Listener, pay attention here.

The first, GI risk.

Still the most common, and it can be fatal,

bleeding, ulcers, perforation.

It happens because you're often inhibiting that protective CoX1.

Sometimes, for high -risk patients, doctors might add another drug like mesoprostol to try and protect the stomach lining.

Okay, GI risk number one.

What's two?

Kidney risk.

Your kidneys use prostaglandins for normal function, especially regulating blood flow when things are stressed, like dehydration.

NSAIDs block those prostaglandins.

So they can damage the kidneys.

They can cause acute kidney injury, yeah.

The risk is much higher if someone's dehydrated or if they're already taking other drugs that stress the kidneys, like diuretics or ACE inhibitors.

Got it.

GI, kidney.

What's the third?

Cardiovascular risk.

This is the one highlighted by the CoX2 inhibitor issues, but it applies to most NSAIDs to some degree.

An increased risk of thrombotic events, blood clots, leading to heart attack and stroke.

So not just the CoX2 selective ones.

No.

The warnings apply more broadly now.

Diclofenac, high -dose ibuprofen, like over 2 ,400 milligrams a day, and the CoX2s are often highlighted.

But the risk exists across the class.

So either absolutely contraindicated for pain relief right after coronary artery bypass graft surgery, CIBG.

CIBG surgery is a definite no -go.

And pregnancy.

Should be avoided, especially after 36 weeks gestation due to bleeding risks for mother and baby.

And crucially, let's talk about kids.

Yes.

This is vital.

Aspirin.

Absolutely contraindicated in children or teens with flu -like symptoms.

The risk is Ray syndrome.

Ray syndrome.

What is that exactly?

It's a rare but devastating illness.

Acute encephalopathy, brain swelling, and liver damage.

It can be fatal.

That link with aspirin during viral illness is strong.

That's why acetaminophen or ibuprofen are the go -to for kids' fever and pain.

No aspirin for flu or chicken pox symptoms.

Hashtag toxicity and overdose management.

Okay, let's shift to toxicity.

What happens if someone takes too much aspirin, maybe chronically?

Right.

So chronic overuse leads to something called salucilism.

The classic signs depend a bit on age.

In adults, the most common thing you hear about is tinnitus ringing in the ears and maybe some hearing loss.

Tinnitus, okay.

And in kids?

In children, it often shows up more as hyperventilation, and CNS affects drowsiness, confusion, agitation.

And what about a massive acute overdose of aspirin?

That's a serious medical emergency.

Figuring out how bad it is isn't just about how many pills were taken, it's also about when they were taken relative to when you measure the blood level.

Time matters.

Hugely.

There are tools, like the dunomogram, which plots the serum salicylate level against the time since ingestion.

It helps guide treatment.

And the treatment.

It's intensive.

You need to prevent more absorption, correct the body's fluid, electrolyte, and acid base balance.

Salicylate overdoses often cause a nasty metabolic acidosis, and sometimes you need to actively remove the drug from the body.

How?

For severe cases, hemodialysis can be life -saving to pull the salicylate out of the blood quickly.

Okay.

Now, what if someone overdoses on, say, ibuprofen instead of aspirin?

Is it the same?

Generally, no.

Overdoses of non -salicylate anesthetics like ibuprofen are usually less dangerous.

Treatment is more supportive, maybe activated charcoal if they get to the hospital quickly, managing symptoms.

And dialysis.

Does that work for ibuprofen?

No.

Hemodialysis is typically not effective for removing most non -salicylate anesthetics.

Different chemical properties mean it doesn't get filtered out well.

Hashtag Sherrick, anti -gout drugs.

Okay, let's switch gears now to a specific inflammatory condition.

Gout.

Ah, yes, gout.

Very painful, I hear.

What's the underlying problem?

It boils down to hyperuricemia, too much uric acid in the blood.

Uric acid is just a normal waste product from breaking down purines, which are found in our cells and in certain foods.

So too much uric acid?

What happens then?

It can crystallize out of the blood and deposit in tissues, especially joints.

And these uric acid crystals are like tiny sharp needles.

That's what causes the intense pain and inflammation of a gout attack.

Ouch.

So how do we treat it?

You mentioned endocides are used for the acute attack pain.

Yes.

Endocides are often first line for the immediate pain and inflammation of an acute gout flare.

But for long -term management or for people with recurrent attacks, we have drugs that target the uric acid problem itself.

There are basically three different approaches.

Three strategies.

Okay, what's the first?

Strategy one is to stop the body from making so much uric acid in the first place.

The main drug here is allopurinol.

Allopurinol.

How does it work?

It blocks an enzyme called xanthine oxidase.

This enzyme is crucial in the final steps of uric acid production.

So block the enzyme, you reduce the production.

It's great for people whose gout is caused by overproducing uric acid.

Any major downsides to allopurinol?

Yes.

You have to watch out for potentially severe, even fatal skin reactions like Stevens -Johnson syndrome or toxic epidermal necrolysis.

Rare, but serious.

Okay, so blocking production is one way.

What's strategy two?

Strategy two is to help the body get rid of more uric acid, increase excretion.

This is done by uricoceric drugs, the main one being probenacid.

Probenacid?

How does that work?

Like opening the floodgates?

Kinda, yeah.

It works in the kidneys.

It stops the kidneys from reabsorbing uric acid back into the bloodstream so more of it gets flushed out in the urine.

Makes sense.

Is it good for everyone?

There's a big catch.

Yeah.

It doesn't work well if the patient already has significant kidney impairment.

If the kidneys aren't filtering properly to begin with, probenacid can't really force them to excrete more uric acid.

Okay, so block production, increase excretion.

What's the third strategy?

Strategy three is to target the inflammatory response to the crystals, rather than the crystals themselves.

This uses colchicine.

Colchicine?

That sounds like an old drug.

It is.

It's been around forever.

Its exact mechanism is complex, but basically it dampens down the inflammatory cell's reaction to those sharp urate crystals.

It helps calm the acute attack.

So why isn't it used all the time?

Because it has some pretty nasty side effects itself, especially severe gastrointestinal issues and can cause bleeding in the GI or urinary tracts if used long -term or in high doses.

So it's usually reserved for short -term treatment of acute flares or sometimes low dose prevention.

Got it.

Three different angles on tackling gout.

Anything else crucial for gout patients?

Yes.

Patient teaching is huge,

especially with allopurinol.

Patients need to drink a lot of fluid, maybe up to three liters a day to help flush things through and prevent uric acid kidney stones.

Three liters?

Wow.

Yeah.

And diet matters.

They need to limit foods high in purines, things like organ meats, certain red meats, some seafood like sardines and mussels, yeast extracts, some beans and peas, oatmeal,

and definitely alcohol, especially beer.

Okay, let's tie this all together.

For the listener, the student, the practitioner,

what are the absolute must -know clinical points?

The so -what factor.

Let's start with assessment.

Right.

Before anyone starts on long -term NSAI therapy, you must get baseline kidney and liver function tests,

BUN, creatinine, liver enzymes.

You need to know where they're starting from, given the risks.

Makes sense.

What else to check?

Ask about allergies, of course, but specifically look for the aspirin triad, a history of asthma, nasal polyps, and rhinitis.

Patients with this triad have a much higher risk of having a serious allergic reaction to aspirin.

Aspirin triad.

Good one to remember.

And always keep in mind that NSAIDs can mask symptoms.

They reduce pain and fever, which might hide an underlying infection.

So your assessment needs to be thorough.

Don't just rely on the absence of fever.

Okay.

Critical assessment points covered.

Now, implementation and teaching.

What are the key do's and don'ts?

Big one.

If the NSAID isn't enteric -coated, take it with food, milk, or maybe an antacid.

Helps minimize that GI upset.

But if it is an enteric -coated or sustained -release tablet, never, ever crush or chew it.

That destroys the protective coating or the release mechanism, dumping the whole dose at once and potentially causing significant stomach irritation or toxicity.

Never crush or chew coated sustained release.

Got it.

What else?

Surgery.

This is a huge safety point.

Patients need to stop taking NSAIDs, including aspirin, unless specifically told otherwise for cardiovascular reasons, at least one week before any planned elective surgery.

One week.

Why?

Because the bleeding risk.

You need to give the body time for platelet function to return to normal, especially after irreversible inhibitors like aspirin.

Showing up for surgery, still taking an NSAI, that surgery might get canceled.

Right.

You don't want uncontrolled bleeding during an operation.

Good point.

Any other tips?

Like, for storing aspirin?

Yeah, actually, if aspirin starts to smell like vinegar, it means it's breaking down chemically.

It shouldn't be used.

Vinegar smell, bad aspirin.

Easy reminder.

Okay, what about evaluating if the treatment is working?

For general anti -inflammatory effects, like with ibuprofen for arthritis,

patients need patience.

It might take a week, maybe longer, to feel the full benefit.

It's not always instant relief, like simple pain relief might be.

Set expectations.

Takes time.

Exactly.

For gout, evaluation is a bit more straightforward.

Are the acute attacks less frequent or severe?

Is the joint pain better during an attack?

And are the serum uric acid levels coming down into the target range on follow -up blood tests?

Hashtag outro.

Okay, we have covered a ton of ground today.

A real deep dive.

We unpacked that whole arachidonic acid cascade, right?

Mm -hmm.

The two pathways, leukotrienes and prostaglandins.

And hammered home that critical difference between the generally protective Keo -X1 and the inflammatory Keo -X2.

Which led us straight into the NSAID aspirin's unique action, the Keterolac Warning, the COX2 story.

And that crucial triple threat of NSAID adverse effects, GI, kidney, cardiovascular, plus the vital raise syndrome warning for aspirin in kids.

Yep.

Then we tackled gout -blocking production with allopurinol, boosting excretion with probenicid, and calming the inflammation with colchicine.

And wrapped with those key nursing takeaways on assessment, administration, and patient education.

Right.

But here's something to really chew on, a final thought maybe.

We use these drugs, these powerful NSAIDs, all the time to suppress inflammation symptoms.

The pain, the swelling.

Yeah, that's the point.

Right?

Relief.

It is.

But inflammation itself, it's the body's intended response.

It's protective.

It's meant to heal, to wall off damage.

So given the very real systemic risks we've discussed, dangers to the gut, the kidneys, the heart, you have to ask.

At what point does our drive for symptom relief actually start to outweigh the potential harm of interfering with that fundamental protective process?

When does suppressing the defense mechanism become more dangerous than the thing it's defending against?

That's a really important question.

Definitely food for thought.

Thank you for breaking all this down today.

My pleasure.

And thank you, our listener, for joining us for this deep dive.

We hope this breakdown helps you navigate these crucial medications safely and effectively.