Geriatric Pharmacology

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Geriatric Pharmacology Polypharmacy
Problemsfor Physical Therapists

• Marilyn James-Kracke, Ph.D.
• Associate Professor of Pharmacology
• University of Missouri - Columbia Medical School

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Lecture outline

• 1. Why physical therapists benefit from knowing
  some basic pharmacology.
• 2. Why elderly people experience more adverse
  drug reactions.
• 3. Which medications can cause problems that
  affect the work of physical therapists.

PT
Pharmacology
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Physical Therapy and Pharmacology

• Ovid search since 1966 13 papers - most from an
  Australian group G. Lansbury et al.
• Hypothesis Physical therapists 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 in Australia to see if
  their hypothesis was correct.

• 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 teach pharm or stop prescribing.

My conclusion -this pharmacology 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
• Elderly distrust medications they dont
  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!
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Adverse Drug reactions more common in the elderly
of people taking a drug
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.
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Magnitude of the Medication problems in the
elderly

• Patients gt65 years old were 13 of the population
  by 2000.
• Patients greater than gt85 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

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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.
How many prescription medications are too many?
gt4 or gt6 Many elderly people receive 12
medications per day
Polypharmacy
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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
anesthetics but may contribute to lower interest
in physical activity - lower clearance of drugs

Note - drug absorption is normal in the elderly
- slow GI tract gives plenty of time for
absorption
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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.

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Reasons why elderly have compliance problems for
taking medications

• 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 - cant recall a few moments
  ago
• cost of medications are prohibitive -- food vs.
  medications
• adverse drug reactions limit benefit of
  medications
• Bottom line - youre 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!!
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Medication problems that affect the physical
therapists work

• Deafness - problem communicating
• visual acuity - problem seeing demonstration
• drowsiness /or mental status - remembering
  instructions
• balance, fainting, strength,
• cardiovascular strength
• respiratory ability-oxygenation -ability to use
  inhalers?
• abdominal discomfort
• joint pain, range of motion
• bruising
• skin rashes - skin thinning, cracking, bleeding

Beta2 agonist relax bronchioles albuterol
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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

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Drugs that cause drowsiness and loss of mental
accuity

• 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 Parkinsons while
  higher concentrations for depression can cause
  insomnia.

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Abdominal discomfort

• Constipation, inability to void the bladder
  completely, stomach and gastric ulcers, inflamed
  bowel disease.
• drugs that cause these problems are
• 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 - called probiotics.

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Drug induced muscle wasting catabolism,
anorexia, cachexia

• 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 - Parkinsons 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.

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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

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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.

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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
• diuretics (dehydration)
• blood pressure lowering medications
• Ineffective Parkinsons 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

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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

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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

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Drug Induced oculotoxicity (vision impairment)

• Allopurinol - used to treat gout - can cause
  cataracts
• amatadine - antiparkinsons antiviral - corneal
  opacities
• amiodarone - antiarrythmic corneal microdeposits
  -reversible
• - 10 of patients - high incidence of
  hypothyroidism too!
• 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

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The END