Polypharmacy in the Elderly – Notes to accompany PPT
#2 – Why is the topic of polypharmacy important to a practicing otolaryngologist?
As outlined in this slide, it is because polypharmacy (use of multiple medications,
whether prescribed or over the counter) is most common in the elderly, can lead
to significant medication related adverse events, and is the main contributor to
patient non-adherence to a prescribed medication regimen.
#3 – This slide about Adverse Drug Events (abbreviated “ADE”) points out that,
in the elderly, ADEs are common; costly, in terms of morbidity, mortality, and
money spent dealing with their consequences; and many are preventable.
#4- This slide covers the 3 basic areas of information to be presented in this slide
presentation, namely the basic concepts about prescribing medications in the
elderly and particular medications to avoid, or which require special caution when
using, in the elderly.
#5 – There are a few facts about the elderly that can assist in learning and
remembering about how to use medications correctly and avoid ADEs. These
include information related to medication pharmacokinetics and
pharmacodynamics.
The elderly have lower lean body mass, and therefore lower total body water,
compared to younger adults. Even if one weighs the same at 75 years of age as
at age 40, they will have more body fat and less muscle mass.
The elderly also have slower metabolism of many medications and usually have
increased end organ sensitivity.
Taken together, these changes, which occur with normal aging, affect medication
tissue distribution and tissue and serum levels. It means that lower doses of
medication and sometimes more widely spaced dosing regimens are appropriate
for the elderly.
The elderly also have lower levels of serum binding proteins and take more
medications. For medications that are highly protein bound, this means more
competition for limited binding sites, and more likelihood that free (active) drug
levels for each medication will be higher. It also means that if the medications
are metabolized by the same system, they could compete in the metabolic
pathway and this could result in slower metabolism (and higher active drug
levels).
The above, coupled with the fact that the elderly have less physiological reserve,
means that a small change in medication can lead to a bigger change in
medication level and medication action, which can manifest as clinical symptoms
and signs in the elderly.
Therefore, always be cognizant of potential drug-drug interactions!
#6 Case 1 (self explanatory)
#7,#8 - Important points of this case are that (a) one should always be cognizant
of what medications a patient is taking BEFORE prescribing an additional
medication, and (b) there are certain common medications which are highly
protein bound and which, when their levels are changed even slightly, will
drastically affect their action (narrow therapeutic-toxic window).
Theophylline, as demonstrated by this case, is one of those common
medications that has a narrow therapeutic-toxic window. The newly prescribed
fluoroquinolone, because it competes for the same metabolic pathway as
theophylline, resulted in slowed theophylline metabolism, higher serum levels,
and toxic side effects. Digoxin and warfarin are the other 2 common
medications used in the elderly that need to be carefully considered prior to
prescribing of any new medication.
#9 - Case 2 (self explanatory)
#10 – Diphenhydramine (brand name Benadryl) is an inexpensive
nonprescription medication that is often used in outpatient and inpatient settings
as a hypnotic (sleep aid). However, it is strongly anticholinergic and highly
associated with side effects in the elderly, especially delirium, urinary retention
and falls. It should NOT be used in the elderly for sleep. It can be used to
prevent or treat allergic reactions in the elderly, but low doses should be used
and the patient warned about and/or monitored for side effects.
In this case, the diphenhydramine prescribed for sleep caused the patient to be
confused (delirious) and unsteady on her feet, so that she fell when getting up
during the night and suffered a major adverse event (fall with hip fracture).
Diphenhydramine is on the list of medications that are inappropriate for use in the
elderly. (Beers Criteria)
#11 – The Beers’ Criteria is a list of medications that, based on the reported
literature, have risks for side effects in the elderly that outweigh any benefit the
medication may have. This list has two parts, one that has medications that are
inappropriate for use in the elderly at any dose or indication, and one that lists
medications that can be used with caution for certain indications or at certain
(low) doses. This list was developed originally in the last 1980s by a multidisciplinary group, and it has been updated twice. The last update was in 2003
(reference given)
#12, #13 – Slides list some medications of interest that are on the Beers’ list of
“inappropriate to use in the elderly” at any dose. Codeine is not on the Beers’
Criteria list and it is inexpensive, but it isn’t used much for older persons because
it has a higher incidence of adverse effects than some of the other narcotics and
cough suppressants.
#14,# 15 – There are several classes of medication which are commonly used,
even in the elderly, but which can result in ADEs much more frequently in the
elderly than in younger adults. These medications are diuretics, ACE inhibitors,
and sulfonylureas. These medication categories are listed, not because they
shouldn’t be used in the elderly, but because if an elderly patient is already one
of these medication types, you need to be cognizant of ADEs that may arise,
particularly if the patient gets an acute illness, undergoes a procedure, or has a
new medication added that may exacerbate the problems.
The types of problems that may arise with these 3 classes of medications are
noted.
#16 – Case 3 (self explanatory)
#17, #18 – Corticosteroids are used commonly, but significant effects of these
agents on the central nervous system, such as confusion or hallucinations, are
primarily seen in the elderly. Although this case is in a patient who received
intravenous corticosteroids, the problem can arise with oral corticosteroids as
well.
This does not mean that corticosteroids should be avoided in the elderly, but their
use needs to be (a) carefully considered, (b) be initiated at the lowest effective
dose, and (c) monitored for potential side effects (such as altered mental status).
In the case of an outpatient prescription, warn the patient and/or family about
potential side effects so they can stop the medication immediately if occurs.
#19 – This slide lists of some medications that have a high propensity to cause or
worsen cognitive impairment (confusion, delirium) in the elderly. Again, this is
not to say these medications shouldn’t be used in the elderly, but potential effects
on cognition need to be monitored during use. Also, if a patient is already on one
of these medications and another medication is added that increases its serum or
tissue level, cognitive problems may arise as a result of the drug-drug interaction.
#20 – Case 4 (self explanatory)
#21 – Proton pump inhibitors (PPIs) can slow the metabolism of warfarin, leading
to an increase in INR and subsequent bleeding. Remember that warfarin is one
of those medications with a narrow therapeutic-toxic window. Many agents can
affect (increase or decrease) warfarin levels and thus lead to an increase or
decrease in INR.
If you prescribe any medication to a person on warfarin, check to see if that new
medication can affect warfarin action and, if so, have the person either alter their
dose of warfarin or get an INR recheck soon.
#22 – Case 5 (self explanatory)
#23, #24 – Pain control in the elderly is not always effectively accomplished and
narcotics do need to be used if the situation warrants. Narcotic side effects, such
as constipation, urinary retention, and confusion, however, occur much more
frequently and at lower doses in the elderly. Because of increased likelihood of
narcotic side effects in the elderly and because elderly often need less analgesia
to achieve the same pain control as younger adults, other pain treatments are
often tried first. Acetaminophen, scheduled at four times a day dosing, or
NSAIDs, given with meals, are examples. Short term routine dosing of
analgesics usually provide better pain control than “prn” dosing, as many elderly
don’t take “prn” medication until their pain is very severe and perhaps beyond a
pain threshold that is not well treated with the analgesic.
Since many older persons have some baseline constipation, when starting a
narcotic, a bowel regimen also should be initiated concomitantly (don’t wait until
severe constipation, impaction, and abdominal pain occurs).
#25 – This patient was given Oxycontin, a long acting medication, as her initial
analgesic. The dosage was too high for her, the narcotic levels built up over
time, and several days after starting the medication she developed both altered
mental status and severe constipation.
When initiating narcotic therapy in any person, NEVER start with a long acting
agent. You first have to ascertain, using short acting formulations (oxycodone,
hydrocodone, morphine, etc), the efficacy (dosage requirement) and side effect
profile of the narcotic in each patient.
#26 – Case 6 (self explanatory)
#27 – When prescribing a new medication it is necessary to take into account
what other medical conditions the patient has, so as to avoid or minimize
exacerbation of those conditions by the new medication. In this case, both
medications prescribed, the antihistamine and the decongestant, exacerbated
the patient’s baseline compensated urinary bladder outlet obstruction and led to
acute urinary retention, requiring and ER visit and Foley catheter placement.
#28, #29 – These slides summarize the important points to remember about
medication use in the elderly. Applying this information to your clinical setting
can help you avoid causing iatrogenic illness and may improve medication
compliance.