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Welcome back to The Deep Dive.
We're here to break down complex clinical info into knowledge you can use right away.
And today, we're diving into something really fundamental for advanced practice, pharmacotherapy in older adults.
Absolutely critical stuff.
We're zeroing in on chapter five, which, you know, tackles this unique patient group.
They often have multiple chronic conditions.
Frailty is common.
And navigating care gets complicated with, well, everything from delivery systems to new tech.
Right.
So our mission today is pretty clear.
Yep.
Quickly unpack those core differences in physiology.
The PKPT shifts highlight the big prescribing dangers like ADRs and polyparmacy and really distill those essential safety guidelines clinicians need for this population.
Yeah.
We'll lay out how aging changes drug handling kinetics and dynamics and introduce those key frameworks like the beers criteria and choosing wisely.
These are really indispensable guides for safer practice.
Okay.
Let's get into it.
The physiological changes that make geriatric dosing so different.
We're talking pharmacokinetics first, what the
Well,
absorption, interestingly, often stays relatively okay.
You might see things like decreased gastric acid or slower motility, but the longer time in the GI tract often compensates.
The real action or maybe the real trouble starts with distribution.
Ah, okay.
This is where body composition changes come in, right?
Less water, less muscle, more fat.
What does that actually do clinically?
It does a lot.
It's a pretty significant shift.
By age 80, you could be looking at 10 to 15 % less total body water and lean mass, but proportionally more body fat.
And this sets up while two immediate major risks.
Okay.
Lay them out for us.
First, with less lean mass, you generally have lower serum albumin, maybe down by 20%.
Albumin binds many drugs.
So for drugs that are highly protein bound, think warfarin, phenytoin less albumin means more free drug floating around.
Right.
And the free drug is the active drug.
Exactly.
So a standard dose can suddenly become toxic, even if the total drug level looks okay on a lab test.
It's a tricky situation.
Yeah, that sounds like a nightmare to manage.
What's the second risk?
The second risk relates to that increase in body fat.
For lipophilic drugs, the ones that like fat tissue, there's now a much larger area for them to spread out into.
We call this an increased volume of distribution or V dollars, and the result, much longer half -lives, potential for massive accumulation.
Can you give an example?
Sure.
Diazepam is a classic one.
Its half -life might be around 20 hours in a younger adult.
In an older adult, it can easily exceed 70 hours.
70 hours.
Wow.
So you're dealing with the effects of doses from days ago.
Accumulation seems almost inevitable then.
Okay.
Let's shift to clearance metabolism and elimination.
How does the body get rid of the drug?
Metabolism takes a hit, specifically phase I metabolism.
This is the oxidative breakdown, mainly in the liver, for many fat -soluble drugs.
It slows down considerably with age.
This reduces clearance for common drugs like, say, amlodipin, codeine, theophylline.
Box 5 .3 in the text lists quite a few.
Interestingly, phase II metabolism, which is conjugation, seems generally unaffected.
Okay, so phase I slows down, and what about the kidneys?
We know renal function declines.
It does.
The glomerular filtration rate, the GFR, generally drops about 1 % per year after age 40.
But here's a really critical clinical point.
You cannot rely solely on the serum creatinine level in older adults.
Why not?
That seems counterintuitive.
Because serum creatinine production depends on muscle mass.
Older adults have less lean body mass, so they produce less creatinine baseline.
This means someone could have significantly impaired kidney function, but still show a serum creatinine level that looks normal, or even low.
It's deceptive.
So what's the takeaway for practice?
You must estimate creatinine clearance using a formula, like Cockcroft -Gault or MDRD.
It's the only reliable way to gauge renal function for dose adjustments, especially for drugs cleared by the kidneys.
It's not optional, really.
Okay, that covers pharmacokinetics, how the body handles the drug.
Now let's flip to pharmacodynamics, or PD.
What the drug does to the body.
Are older adults more sensitive?
Absolutely, particularly the central nervous system effects.
They're often grossly exaggerated.
There seems to be increased sensitivity at the receptor level, or maybe reduced capacity to compensate.
Drugs with anticholinergic effects are prime offenders.
Think older antihistamines, tricyclic antitouch oppressants.
What kind of problems do they cause?
It's not just the usual dry mouth and constipation, though those happen.
They can trigger acute confusion, delirium, make BPH worse.
And another big one, loss of the baroreceptor reflex.
This directly increases the risk of orthostatic hypotension.
Which leads to falls.
A huge issue.
Exactly.
Falls are a major consequence.
Okay, this leads us perfectly into the big thorny problem of polypharmacy.
And it's not just about the number of pills, is it?
No, not just the number.
It's the use of an inappropriate amount or combination of medications.
It's driven by multimorbidity, something like 80 % of older adults have two or more chronic conditions.
Plus, you have patient expectations and sometimes multiple specialists prescribing without maybe coordinating fully poly providers, as the chapter calls them.
And this fuels that dangerous cycle.
The prescribing cascade.
Can you walk us through a common example?
Sure, a classic one.
A patient starts an NSAID for arthritis.
They develop maybe some subtle GI side effects, maybe some edema.
The clinician sees the edema, thinks it's heart failure, and prescribes a diuretic.
The diuretic causes dizziness or dehydration, leading to a fall.
Now, the patient has another problem, maybe needing pain meds for the fall injury, all triggered by the side effect of the first drug being misinterpreted.
It's kind of terrifying.
And the stats back it up.
Adverse drug reactions, ADRs, causing 30 % of hospital admissions for folks over 65.
It's a staggering number.
If we could just interrupt that cascade more effectively.
Yeah.
And then there are the hidden risks, right?
Lifestyle factors, OTCs, things patients might not even think to mention.
Definitely.
We have to ask specifically.
Alcohol is a big one.
It potentiates CNS, affects lethargy, confusion, and worsens hypotension with cardiovascular meds.
And remember, alcohol can hide in OTC cough syrups, mouthwashes.
We need to be aware of that.
About 14 % of men and 1 .5 % of women over 65 might have alcohol use disorder, so it's prevalent.
Good point.
And what about caffeine and nicotine?
The chapter mentions tables 5 .3 and 5 .4.
Right.
Nicotine is an enzyme inducer in the liver.
It speeds up metabolism, potentially decreasing effectiveness of things like analgesics, theophylline, beta blockers.
And for women on estrogen, it significantly bumps up the thrombosis risk.
Caffeine, on the other hand, can have its own effects prolonged by certain drugs, like ciprofloxacin or semididine, leading to maybe insomnia or anxiety.
Plus, it can interfere with iron absorption.
These are the kinds of interactions easily missed in a busy clinic if you don't specifically ask.
Precisely.
You need a systematic review of everything.
RX, OTC, herbals.
Okay, so given all these risks, the PKPD changes, polypharmacy, hidden interactions, what's the guiding philosophy for prescribing?
We all know, start low, go slow.
Yes, but there's a crucial addition.
Start low, go slow, but get there.
Get to the therapeutic dose.
It's a balance.
We start low because of those slower clearance rates and increased sensitivity, but we can't be so cautious that the patient never actually gets the benefit of the medication.
We need to titrate carefully to efficacy.
And tools like the Beers Criteria and Choosing Wisely help with that balancing act.
Absolutely.
They are essential guides.
The Beers Criteria, the 2019 update is mentioned, lists potentially inappropriate medications.
And Choosing Wisely highlights areas where we often overuse or misuse treatments.
Let's dig into some of those Choosing Wisely points.
They seem really practical for everyday decisions.
What about dementia and behavioral symptoms?
This is huge.
The absolute first -line approach must be non -pharmacologic interventions.
Trying to manage behavioral symptoms like agitation or anxiety with environmental changes, routine, reassurance first.
Anti -psychotics should not be the first choice.
The risks stroke, premature death are serious.
They should only be considered for imminent threat or extreme distress and always with informed consent.
And the regulations reflect that urgency, right?
They do.
CMS has very strict limits, especially in long -term care.
PRN psychotropics need review every 14 days.
For anti -psychotics, it's a hard stop.
A new order with documented justification is needed every 14 days period.
It forces reassessment.
Okay.
What's another key Choosing Wisely area?
Antibiotic use.
Specifically,
avoid treating asymptomatic bacteriuria.
Just finding bacteria in the urine of an older adult without clear UTI symptoms doesn't warrant antibiotics.
It provides no benefit and just fuels antibiotic resistance.
Only culture the urine if there are clear signs pointing to a UPI.
Stop treating the dipstick or the lab report in isolation.
Makes sense.
And the third one mentioned is diabetes management.
Yes.
Specifically targeting hemoglobin A1C.
In most older adults, aiming for an A1C below 7 .5 % is often too aggressive.
The risk of dangerous hypoglycemia causing falls, confusion, even cardiac events outweighs the long -term microvascular benefits for many.
Moderate control is generally safer.
Also, a strong recommendation to avoid sliding scale insulin, SSI, for long -term management.
It's just reactive, not physiologic.
Basal insulin or bevalabolous regimens are much preferred.
Okay.
Really important practice points there.
Now, let's quickly touch on a few specific high -risk drug classes mentioned in the text, keeping those PKPD changes in mind.
Axiolytics.
Especially benzodiazepines.
The long half -life ones like diazepam or flurzapam are particularly bad high -risk for falls, cognitive impairment, sedation.
If a benzo is truly needed, short -term use of a shorter acting one like lorazepam or oxazepam is much preferred.
But honestly, for chronic anxiety and frail older adults, SSRIs like sertraline often have a better risk -benefit profile.
And antidepressants themselves.
SSRIs are generally preferred over older tricyclics.
The TCA's like amitriptyline.
TCA's have significant anti -cholinergic and cardiovascular side effects, orthostasis, arrhythmias.
Confusion just too risky for most older adults.
But even SSRIs aren't risk -free.
We need to watch for hyponatremia, especially early on, and they can still increase fall risk.
So, still need vigilance.
Got it.
And finally, everyday pain management.
Acetaminophen and NSEIs.
With acetaminophen, the main thing is the maximum dose don't exceed 4 ,000 milligrams in 24 hours, and be even more cautious with liver disease or significant alcohol use.
NSAIDs, especially long -term, are a major concern.
Big risks of GI bleeding and renal insufficiency.
And don't forget, NSAIDs are highly protein -bound.
They can displace other highly -bound drugs like warfarin or degoxin, suddenly increasing their free levels and toxicity risk.
Another hidden danger.
So many potential pitfalls.
This brings us to the final crucial piece.
Adherence and monitoring.
We've prescribed the right drug, right dose, but does a patient actually take it correctly?
Yeah, that's a huge challenge.
The chapter notes up to 40 % of older adults might take meds improperly.
Reasons very cost is one, though the Medicare Part D gap closure helped somewhat.
Unpleasant side effects are big dry mouth, fatigue,
dizziness, and then physical or cognitive changes.
Poor vision -making labels, hard to read, arthritic hands struggling with bottles, dementia causing memory issues.
So what are the practical, actionable things we can do as clinicians beyond just writing the script?
Box 5 .4 talks about guidelines for safe prescribing.
The core principle is simplification.
Make the regimen as simple as humanly possible.
Least frequent dosing, lowest effective dose, combine meds if possible, and communication is key.
Provide written instructions, large print if needed.
Clearly list both brand and generic names, and crucially state the reason for the drug in simple terms.
Water pill for fluid, not just furosemide 40 mg.
That makes sense.
Helps the patient or caregiver connect the pill to its purpose.
What else helps?
Encourage pill planners, dosage containers, whatever helps organize things.
And routine medication reconciliation is non -negotiable.
You have to review everything, prescription, OTC, herbals, supplements at visits.
Patients often don't consider OTCs or herbals real medicine, so they won't mention them in unless you ask directly.
Good reminder.
And finally, therapeutic monitoring.
Absolutely essential for narrow therapeutic index drugs, warfarin, digoxin, theophylline, anticonvulsants.
Regular labs are required.
And also for drugs that impact kidney function, like ACE inhibitors, we need to monitor electrolytes and renal function periodically.
It's how we catch problems before they become serious ADRs.
Okay, it feels like we've covered a lot of ground.
Let's wrap up by revisiting those three foundational quotes mentioned in the chapter.
They really seem to capture the essence of geriatric pharmacotherapy.
They really do.
They're worth keeping top of mind.
First, any symptom in an elderly patient should be considered a drug side effect until proved otherwise.
That's from Dr.
Gurwitz and Leslie Fine.
It forces you to think medication first when a new problem arises.
Always look for the prescribing cascade first.
Exactly.
Second, start low, go slow,
but get there.
That captures the careful titration needed balance safety with achieving the therapeutic goal.
Find that sweet spot.
Right.
And third, a medication only works if the patient takes it.
That's C.
Everett Coop.
It brings it all back to adherence, education, simplification, and ensuring the patient can actually follow the plan.
Perfect summary.
And one last provocative thought for everyone listening.
Yeah.
Always integrate the patient's goals of care and their overall life expectancy into prescribing decisions.
Does aggressively lowering cholesterol with a scatting make sense for someone with a very limited prognosis where the potential benefit is years away but the risks or burdens are immediate?
That constant reevaluation tailored to the individual is really the hallmark of expert advanced practice in this area.
Well said.
Mastering these principles isn't just about avoiding errors.
It's about genuinely improving the quality of life for our older patients.
Couldn't agree more.
Thanks for walking us through that complex landscape, and thank you all for joining us on the Deep Dive.
We'll catch you next time.