Download Geriatric Pharmacology &Polypharmacy

Geriatric Pharmacology
& Polypharmacy Problems
for Physical Therapists
Marilyn James-Kracke, Ph.D.
Associate Professor of Pharmacology
University of Missouri - Columbia
Medical School
1. Why physical therapists benefit from
knowing some basic pharmacology.
PT
2. Why elderly people experience more
adverse drug reactions.
3. Which medications can cause problems that
affect the work of physical therapists.
Pharmacology
Lecture
outline
Physical Therapy
and Pharmacology
• Ovid search since 1966 = 13 papers
- most from an Australian group G.
Lansbury et al.
• Hypothesis Physical therapists
• J. of Allied Health. 2002
• Conclusions
• A substantial proportion of
practicing physical therapists
in Australia advised and
administered OTC
medications despite their
limited training and
knowledge in the area.
• In their opinion, this practice
adds occupational risk - either
often have limited knowledge and
little formal training in
pharmacology, yet they frequently
advise their clients on the use of
over-the-counter (OTC)
medications and administer these in
the course of treatment.
• The Lansbury et al approach was to
perform a survey of 25% of all PTs
teach pharm or stop prescribing.
in Australia to see if their
hypothesis-this
was pharmacology
correct.
My conclusion
class for PT students is unusual and beneficial
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Attitude of the elderly towards
PT
and
medications
Older people are more likely to prefer physical
means than medications to feel better.
• Why
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Elderly distrust medications they don’t understand.
too many medications prescribed for them - confusing
afraid of choking on medications.
Physicians are always changing and rushing them.
for the elderly, PT provides social interaction as well as
health care - they enjoy being with healthy fun therapist.
Elderly trust personal contact - like hands on approach
nuturing approach - encouragement - humor
side effects of the medications often make them feel
worse - disoriented, sleepy, weak, stomach ulcers,
hearing impairment, etc
For the elderly, medication risk is greater and benefit is
less than in younger people.
In contrast, physical therapy has little risk and definite
benefits in both the old and the young.
The physical therapist
is trusted. Older patients
want your advice on
everything including their
medications.
This could be good or bad.
This is probably true
for younger people
also!
Adverse Drug reactions more common in the elderly
= authors of studies
Bounce back time - If an elderly person is started on a new medication and 2 to 3
days later they are taken to the emergency room, suspect a drug reaction.
If a older patient seems very different than at your last PT session, ask
them if they are taking any new medications.
Magnitude of the Medication problems in the elderly
• Patients >65 years old were 13% of the population
by 2000.
• Patients greater than >85 years old are the fastest
growing segment of the population.
• This 13% of the population consumes 30% of all
medications
• Elderly population is expected to triple from 1985
to 2060.
• Elderly are the most physiologically
heterogeneous category - state of health varies
extensively - physical strength, - cardiac condition, renal
and liver function for clearance of drugs.
• Compliance - misuse and errors - side effects
Factors contributing to adverse drug reactions
in elderly patients
Heart, kidney,
liver, thyroid
Orthostatic hypotension, when
they standup, blood goes to their
feet - weak sympathetic nervous
system response to constrict
veins and increase heart rate.
Low thyroid function causes
lower body temperature,
metabolic rate, & heart rate.
Polypharmacy
How many prescription medications are too many? >4 or >6
Many elderly people receive 12 medications per day
Kidney clearance is
reduced
Blood flow to all
organs like kidney
and liver is reduced therefore clearance is
reduced - exercise
may help them clear
more drug by
increasing circulation
Breathing affects
clearance of inhaled
Note - drug absorption is normal in
the elderly - slow GI tract gives plenty anesthetics
but may contribute to
of time for absorption
lower interest in
physical activity lower clearance of
drugs
Biggest errors made in
prescribing for elderly people
• Polypharmacy - a drug for every complaint and elderly
people have lots of aches and pains, circulation and
breathing difficulties etc
• Side effects are missed because they are misinterpreted as
part of getting old - particularly senility - hearing loss etc
• Elderly people often see a different doctor every time and
the next doctor does not realize that the patient was clever
and active a week ago.
• Physicians often assume that the patient is ill because they
are not taking their medications when in fact they are
taking them and the amount prescribed for them too much.
Reasons why elderly have compliance
problems for taking medications
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opening pill containers(weak/arthritis pain/tremors/spills)
fear of choking while swallowing large pills
reading the labels and information
depression - sleepy - poor concept of time for doses
cognitive impairment - can’t recall a few moments ago
cost of medications are prohibitive -- food vs. medications
adverse drug reactions limit benefit of medications
Bottom line - you’re never sure whether they are taking too
much or too little.
Elderly are more likely to tell their PT than their doctor whether they are taking their
medications or not because they are too polite to tell a doctor that his pills make them
feel sicker. You are in a position to make a difference!!
Medication problems that affect the
physical therapist’s work
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Deafness - problem communicating
visual acuity - problem seeing demonstration
drowsiness &/or mental status - remembering instructions
Beta2 agonist
balance, fainting, strength,
relax bronchioles
albuterol
cardiovascular strength
respiratory ability-oxygenation -ability to use inhalers?
abdominal discomfort
joint pain, range of motion
bruising
skin rashes - skin thinning, cracking, bleeding
Dizziness, Fainting and Weakness
• Inner ear disturbances, nauseants, low blood pressure, anemia and
hypoxia, electrolyte imbalances like hypokalemia, dehydration.
• Antihypertensive medications - beta blockers, Ca channel blockers,
diuretics, ACE inhibitors, nitrates, clonidine, alpha blockers orthostatic hypotension - side effect is an extension of the desired
blood pressure lowering.
• Antianginal therapy - nitrates, beta blockers, Ca channel blockers
• Certain antiarrythmic drugs - bretylium, amiodarone
• Drugs that cause anemia - NSAIDs can cause bleeding of the GI tract
which can lead to severe anemia
• Cytotoxic agents used to treat cancers or arthritis or autoimmune
diseases like lupus erythematosis, and to prevent transplant rejection
also inhibit the bone marrow from making red blood cells
– methotrexate
– cyclophosphamide
– azathioprine
– cyclosporine
Drugs that cause drowsiness and
loss of mental accuity
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antihistamines (some are used as sleep aids)
Pain medications
muscle relaxants
antinauseants
some beta blockers - like propranolol
• drugs that cause insomnia - prevent a good night sleep
(caffeine, aminophylline, albuterol) - eventually cause
daytime drowsiness. Low concentration of antidepressant
are sleep aids, amitryptiline in patients with Parkinson’s
while higher concentrations for depression can cause
insomnia.
Abdominal discomfort
• Constipation, inability to void the bladder
completely, stomach and gastric ulcers, inflamed
bowel disease.
• drugs that cause these problems are:
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pain medications containing narcotics - inhibit GI motility
antimuscarinic agents - inhibit motility - slow transit through GI tract.
antihistamines have antimuscarinic side effects
NSAIDs - inhibit prostaglandin synthesis in the gut leads to ulcers
cytotoxic agents for chemotherapy - epithelial cells lining the GI
tract slough off
• antibiotics disturb the normal flora and allow pathogenic bacteria to
grow - causes diarrhea and flatulence - solved by taking antibiotics with yogurt -
Drug induced muscle wasting
catabolism, anorexia, cachexia
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Glucocorticoid steroids used as antiinflammatory agents - body burns glucose and
protein (in muscle) but not fat - causes muscle wasting - fat body & thin limbs
Beta2 agonists - increase blood flow to muscles but high doses cause tremor and low K.
beta blockers - intermittent claudication - pain in muscles causing limping - 4 to 7 % of
patients have this effect
digoxin - hypokalemia = low K - causes muscle and cardiac weakness
diuretics - low K - should receive K supplement or change to K sparing diuretics spironolactone - old people call these water pills.
Angiotensin Converting Enzyme inhibitors = ACE inhibitors (captopril, enalopril) lower
blood pressure but can also cause rhabdomyolosis
Bromocriptine - Parkinson’s patients - dopamine stimulates the chemoreceptor trigger
zone in the brain - anorexia
Methylphenidate - stimulant to treat narcolepsy or attention deficit disorder amphetamine like - similar to agents used in diet pills to suppress appetite.
Chemotherapy - cytotoxic agents cause extreme nausea
Cachexia - increased tumor necrosis factor alpha causes the body to become insensitive
to insulin - starvation in the midst of plenty.
Muscle wasting is more likely due to disease rather than drug induced lack of appetite.
Joint pain, range of motion
• 30 drugs are listed to cause this - but most are low incidence
• injections of microcrystalline steroids into joints = relieves pain,
lasts for a month, shorter relief each time because more rapid
destruction of the joint - greater pain after effect wears off.
• Beta blockers betaxolol pindolol - 7 to 10% experience myalgia
• Cholesterol lowering agents - fenofibrate -rhabdomyolosis
• clozapine - used for abnormal movement disorders and
aggressive behaviors - neuroleptic
• danazol - androgenic steroid
• droloxifene - nonsteroidal antiestrogen
• rifampin - used to treat tuberculosis - first week of therapy
• losartan valsartan- to lower blood pressure, uncommon side effect.
• Ca channel blockers - uncommon
Analgesics - nonsteroidal
antiinflammatory drugs = NSAIDs
• Old arthritic people take more of these but they are also
prone to stomach/intestinal ulceration due to cycloxygenase
inhibition of the synthesis of protective prostaglandins in the
gastric mucosa.
• chronic slow blood loss causes anemia
– look for very pale weak patient
• can be sudden onset - severe hemorrhage
• platelet activity is slowed by NSAIDS
• patients taking these meds should be asked if they have
abdominal discomfort before starting activity
• activity increases blood pressure - may precipitate a bleed
• longer term use of high dose NSAIDs can cause kidney
damage and loss of erythropoeitin made by the kidney which
is a hormone that stimulates red cell production and without it
there is anemia.
Bruising - hematomas
• Vit K is important for making clotting factors - malnutrition causes
bruising -lack of green leafy vegetables in diet containing Vit K
• Anticoagulant dose too high (warfarin-coumadin competes with Vit K)
• NSAIDs - inhibit platelets - causes longer bleeding times
• antibiotics killed bacteria in the gut that make Vit K
• Steroid use - Cushing syndrome - weakens blood vessels
• drugs causing dizziness - orthostatic hypotension cause falls
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diuretics (dehydration)
blood pressure lowering medications
• Ineffective Parkinson’s treatment - excessive falling
• cancer chemotherapy - reduces platelets for clotting and makes a person
weak enough to fall more frequently.
• Intramuscular injections - for people on anticoagulants
• Elder abuse
*Muscle Relaxants - many mechanisms - not well understood - all of
them cause drowsiness as a side effect
•GABAB agonist = BACLOFEN, less drowsiness than benzodiazepines!
• GABAA agonists = Benzodiazepines DIAZEPAM -CLOTIAZEPAM PINAZEPAM QUAZEPAM TETRAZEPAM
•GABA and glycinergic receptors agonist THIOCOLCHICOSIDE
•Spinal reflex blockers, MEPROBAMATE CARISOPRODOL CHLORPHENESIN - METHOCARBAMOL, CHLORZOXAZONE,CYCLOBENZAPRINE TOLPERISONE METAXALONE -
•Imidazo receptor blocker and alpha2 receptor blocker
CLONIDINE, TIZANIDINE - also used to lower blood pressure, ease drug
addiction withdrawal - for smoking and alcohol cessation.
•Blocker of Ca release from Sarcoplasmic Reticulum in
muscles DANTROLENE
•Neuromuscular Cholinergic receptor blockade = Curoniums
ALCURONIUM ATRACURIUM - CISATRACURIUM - DOXACURIUM, ETIZOLAM, KETAZOLAM
MIVACURIUM,- PANCURONIUM, PIPECURONIUM, RAPACURONIUM, ROCURONIUM - TUBOCURARINE
VECURONIUM - used
mainly to produce muscle paralysis in surgery
•Acetylcholine agonist depolarizing blockers SUCCINYLCHOLINE used
in surgery
Drug induced ototoxicity (deafness)
at plasma levels above therapeutic level
• Aminoglycoside antibiotics cause
irreversible deafness - like gentamicin,
tobramycin, amikacin
• antidepressants
• loop diuretics - furosemide (lasix)
• erythromycin azithromycin
• NSAIDs and salicylates [aspirin causes
tinnutis - ringing of the ears but
acetominophen does not] - this type of
hearing loss is reversible
• quinine - tinnutis
• vancomycin
Drug Induced oculotoxicity (vision impairment)
• Allopurinol - used to treat gout - can cause cataracts
• amatadine - antiparkinson’s antiviral - corneal opacities
• amiodarone - antiarrythmic corneal microdeposits -reversible
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- 10% of patients - high incidence of hypothyroidism too!
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anticholinergics - ipratropium atrovent blurred vision and glaucoma
antidepressants - anticholinergic side effects
antihistamines - anticholinergic side effects
anticonvulsants - diplopia (double vision), nystagmus
 -adenergic blocker - reduced tears
bromocriptine - myopia blurred vision
corticosteroids - glaucoma cataracts
digoxin - colored halos - sign of toxicity
methotrexate 25% conjunctivitis
– - reduced tears & photophobia
• phenothiazines - deposits in lens
• tamoxifen - antiestrogens, fine retinal opacities
The END