Geriatric Pharmacology

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Geriatric Pharmacology

• Dr Andrew P Mallon

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Adults gt65 years old

• Fastest growing population in US
• 20 of hospitalizations for those gt65 are due to
  medications theyre taking

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Effects of Aging on Rx use(Absorption)

• Reduced gastric acid production
• Raises gastric pH
• May alter solubility of some drugs (ASA etc)
• Longer gastric emptying
• Delay or reduce absorption
• Decreased esophageal motility
• Capsules more difficult to swallow
• Loss of subcutaneous fat
• Increased rate of absorption of topical
  medications
• Increased fagility of veins
• IV administration more difficult

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Effects of Aging on Rx use(Distribution)

• Decreased cardiac output/circulation changes
• May delay onset or extend effect of medications
• Decrease of lean body mass/increase of fatty
  tissue where medications are stored
• Prolong medications action
• Increase sensitivity
• Increase toxic effects
• Higher plasma levels/more erratic distribution

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Effects of Aging on Rx use(Metabolism)

• Difficult to predict, depends on
• General health nutritional status
• Use of alcohol, medications
• Long term exposure to environmental
  toxins/pollutants
• Aging causes decreased liver mass/ hepatic blood
  flow
• Delayed/reduced metabolism of drugs
• Higher plasma levels
• Lower serum protein levels
• Loss of protein binding
• Idiosyncratic reactions

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Effects of Aging on Rx use(Excretion)

• Reduction in number of functioning
  nephrons/decreased glomerular filtration rate
• Longer half-life of medications
• Increased side effects
• Increased potential for toxicity

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• A story Tom, age 68
• Takes seven different medications
• Cant remember which medication to take when, so
  takes them all at bedtime

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Tom is typical of aging

• Multiple medications to control multiple health
  problems
• Age changes pharmacokinetics, so more vulnerable
  to
• Adverse effects
• Drug interactions (can rob them of therapeutic
  effects of medications theyre taking)

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• Functional impairments
• Vision loss
• Cognitive dysfunction
• Musculoskeletal disorders

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• Sociocultural factors may make person
  unable/unwilling to follow prescribed medical
  regimen
• Loss of family, friends, income
• Limited/fixed income

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• Economic factors
• May have to choose between food and medications
• OTCs instead of expensive doctor visits
• Use of outdated medications
• Use of home remedies
• Share medications
• Nutritional status may affect how body
  metabolizes medications

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Polypharmacy

• Concurrent use of multiple medications
• gt65 12 of population
• Consume 30 of all prescription drugs average
  person takes 4-5 prescription meds
• Consume 40 of OTCs
• Excessive use of drugs
• Overdose of a drug

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Polypharmacy

• Doctors more likely to prescribe medications for
  older clients than young ones
• Altered response to medications cumulative
  effect on physiology of aged
• Aging
• Disease
• Stress
• Trauma

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Polypharmacy

• Elderly rely on various medication to control or
  relieve a range of age-related problems
• Cardiovascular disease
• Diabetes
• Degenerative joint disease
• Autoimmune disorders

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Polypharmacy

• Risks of problems
• Medication errors
• Wrong drug, time, route
• Adverse effects from each drug
• Polypharmacy primary reason for adverse reactions
• Adverse interactions between drugs

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Troublesome medications

• Antacids
• Acid-base imbalance (sodium bicarbonate)
• Constipation (aluminum hydroxide)

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Troublesome medications

• Antiarrhythmics
• Confusion
• Slurred speech
• Light-headedness, seizures
• hypotension

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Troublesome medications

• Anticoagulants
• bleeding

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Troublesome medications

• Antihistamines
• Urinary difficulty
• Short-term memory dysfunction
• Drowsiness, dizziness

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Troublesome medications

• Antihypertensives
• Dizziness and falls
• Orthostatic hypotension

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Troublesome medications

• Antiparkinsons agents
• Uncontrolled movements (grimacing, tongue
  movements, eyes rolling back, twisted neck)
• Dark urine (levodopa)

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Troublesome medications

• Antipsychotics
• Jaundice
• Extrapyramidal symptoms
• Sedation, dizziness (can lead to falls)
• Orthostatic hypotension
• Scaling skin on exposure to sunlight
  (phenothiazines)

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Troublesome medications

• Anxiolytics
• Confusion, lethargy
• Slurred speech
• Ataxia, falls
• Blurred vision

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Troublesome medications

• Corticosteriods
• Sodium retention (may worsen HTN CHF)
• Insomnia
• Psychotic behavior
• osteoporosis

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Troublesome medications

• Digitalis glycosides
• Fatigue
• Loss of appetite, nausea, vomiting
• Visual disturbances
• Nightmares, nervousness
• Hallucinations
• Bradycardia, arrhythmias

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Troublesome medications

• Diuretics
• Fluid/electrolyte disorders
• Dehydration
• Hypotension
• Thiazide diuretics can increase blood glucose
  levels (more insulin for diabetics)

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Troublesome medications

• Hypoglycemics and insulin (especially in people
  with reduced kidney function)
• Hypoglycemia from missed meals, alcohol intake,
  increased exercise

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Troublesome medications

• Laxatives
• Intestinal malabsorption
• Reduced absorption of fat-soluble vitamins (if
  taking mineral oil)
• Magnesium toxicity (clients with renal
  insufficiency taking magnesium)

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Troublesome medications

• Narcotic analgesics
• Respiratory depression
• Constipation
• Urinary retention
• Demerol
• Hypotension, dizzines
• confusion

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Troublesome medications

• NSAIDs
• Prolong bleeding
• Gastric discomfort, bleeding
• Increased risk of toxicity (with impaired renal
  function)

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Troublesome medications

• Respiratory agents
• Restlessness, nervousness
• Confusion
• Blood pressure disturbances
• Palpitations, tachycardia
• Chest pain

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Troublesome medications

• Tricyclic antidepressants
• Dry mouth
• Constipation
• Blurred vision
• Postural hypotension
• Dizziness
• Tachycardia
• Urinary retention

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If client taking gt five meds regularly

• Suggest physician prescribe combination drugs or
  long-acting forms
• Fewer pills to remember
• Suggest re-evaluation of medications periodically
• Encourage client to use one pharmacy
• New medications
• Good information
• Encourage follow up

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Medication aids

• Remove cotton packing
• Store in original container
• Dry place
• Away from heat/light
• Follow dosing instructions
• Get rid of outdated medications
• Avoid sharing medications

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Medication aids

• For those with vision problems
• Large print labels
• Color coded labels

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Medication aids

• Nonchildproof caps
• Memory aids
• If taking antihypertensives
• Get up slowly
• Alternative, non-pharm or herb therapies
• Massage