MEDICATION USE IN OLDER ADULTS

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MEDICATION USE IN OLDER ADULTS
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OLDER ADULTS

• Young-Old Ages 65-74
• Old Ages 75-84
• Oldest-Old Age 85

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OLDER ADULTS

• 12 of population
• 30 of medication use
• 20 of population by 2030
• those age 85 fastest growing segment

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Prescription Drug Use Among Community-Dwelling
Older Alabamians
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Over-the-Counter Drug Use Among
Community-Dwelling Older Alabamians
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MEDICATIONS COMMONLY USED BY THE ELDERLY

• Cardiovascular
• Digoxin
• Diuretics (and potassium supplements)
• Beta blockers
• Calcium channel blockers
• Ace inhibitors
• Nitrates
• Central Nervous System
• Benzodiazepine anxioloytics
• Sedative/hypnotics
• Antipsychotics
• Anti-Parkinson
• Analgesics
• Nonsteroidal anti-inflammatory drugs

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MEDICATIONS COMMONLY USED BY THE ELDERLY (CONTD)

• Endocrine
• Thyroid supplements
• Oral hypoglycemic agents
• Anticoagulant/antiplatelet
• Warfarin
• Aspirin
• Gastrointestinal
• Laxatives and stool softeners
• Antacids
• H2 antagonists
• Supplements
• Vitamins and nutrients
• Potassium
• Calcium

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POLYMEDICINE/POLYPHARMACYTHE EXCESSIVE AND
INAPPROPRIATEUSE OF MEDICATION

• Identifying features
• Use of
• Medications with no apparent indication
• Duplicate medications
• Interacting medications
• Contraindicated medications
• Inappropriate doses
• Medication to treat existing adverse drug
  reaction
• Improvement of condition following discontinuation

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Relationship Between Prescribing Rate and the
Prevalence of Potential Drug Interactions
Number
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FACTORS THAT INCREASE THE RISKOF DRUG
INTERACTIONS

• Increased medication consumption both
  prescription and nonprescription
• Consumption of high risk drugs e.g., warfarin,
  digoxin, cimetidine, phenytoin, theophylline
• Visiting multiple prescribers
• Patronizing multiple pharmacies
• Physiologic and pharmacokinetic changes
  e.g., underlying diseases, altered drug clearance

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Relationship Between Percentage of Patients with
Adverse Drug Reactions and the Number of
Medications Prescribed
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Physiologic Changes in Aging Elderly
Body Fat (as a proportion of body weight)
Plasma Volume
Age 20 to 80 8
Age 20 to 70 35
Total Body Water
Extra-cellular Fluid
Age 20 to 80 17
Age 20 to 65 40
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AGE-RELATED ALTERATIONS IN GASTROINTESTINALFUNCTI
ON IMPACT ON DRUG ABSORPTION

• Physiologic Change Impact
• Diminished salivation Difficulty swallowing
  oral solid dosage form
• Esophageal motility disorders
• Gastric acidity Effect on drug absorption
• not usually clinically
• Gastric emptying time significant
• GI blood flow

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AGE-RELATED ALTERATIONS IN PHYSIOLOGYIMPACT ON
HEPATIC DRUG METABOLISM

• Physiologic Change Impact
• Liver mass Phase I metabolic reactions
• (oxidation, reduction, demethylation,
• Liver blood flow and hydrolytic processes)
  decreased
• Hepatic metabolism
• Phase II metabolic reactions
• (glucuronidation, acetylation, and
• sulfation) unchanged
• Clinical Significance
• 25 to 50 reduction in dosage may be necessary
  for drugs eliminated by Phase I hepatic
  metabolism (e.g., barbiturates, phenytoin,
  warfarin)

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AGE-RELATED ALTERATIONS IN PHYSIOLOGYIMPACT ON
DRUG DISTRIBUTION

• Physiologic Change Impact
• Body size Dosage requirement
• Lean body mass
• Body fat Distribution of fat soluble
  drugs
• Body water Distribution of
  water-soluble drugs
• Serum albumin Free fraction of drug in
  serum
• Clinical Significance
• Physiologic changes may necessitate significant
  dosage
• alterations in the elderly

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AGE-RELATED ALTERATIONS IN PHYSIOLOGYIMPACT ON
RENAL DRUG EXCRETION

• Physiologic Change Impact
• Kidney mass Drug excretion
• Renal blood flow
• Renal tubular function
• Clinical Significance
• Age-related decline in renal function is well
  documented.
• Significance (25 to 50 or more) decrease in
  dosage of
• renally eliminated drugs may be necessary.

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Age Differences In Creatinine Clearance
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Cockcroft-Gault Equation
(140-Age) weight (kg)
Creatinine clearance
72 serum creatinine
Multiply by 0.85 for females
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AGE-RELATED PHARMACODYNAMICALTERATIONS

• Alteration in receptor number and function
• Change in responsiveness of target organ
• Change in homeostatic mechanisms
• Postural control
• Orthostatic circulatory response
• Thermoregulation
• Visceral muscle function

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DRUGS TO AVOID IN OLDER ADULTS(High probability
of adverse outcome with clinical significance)

• Pentazocine (Talwin)
• Flurazepam (Dalmane)
• Amitryptyline (Elavil)
• Doxepin (Sinequan)
• Meprobamate (Miltown, Equanil)
• Chlordiazepoxide (Librium)
• Disopyramide (Norpace)

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DRUGS TO AVOID IN OLDER ADULTS(High probability
of adverse outcome with clinical significance)

• Chlorpropamide (Diabinese)
• Diclyclomine (Bentyl) and other GI antispasmodics
• Methyldopa (Aldomet)
• Digoxin Dose 0.125/day
• Barbiturates
• Meperidine
• Ticlopidine

Arch Intern Med 19971571531-1536.
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INAPPROPRIATE HIGH SEVERITY DIAGNOSIS-DRUG
COMBINATIONS IN NURSING HOMES

• Sedatives/ Hypnotics and COPD
• NSAIDs and active or recurrent gastritis, peptic
  ulcer disease, GERD
• Metoclopramide and seizures or epilepsy
• ASA, NSAIDS, dipyridamole, or ticlopidine and
  anticoagulation
• Anticholinergic drugs and BPH
• Tricyclic antidepressants and arrythmias (if
  started in the last month)

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Inappropriate Drug Use in Homebound Older Adults
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DRUG-INDUCED SYMPTOMS

• Weakness Corticosteroids
• Extrapyramidal symptoms Neuroleptics,
  methyldopa, metocloproamide, amoxapine
• Numbness/tingling/paresthesias metronidazole,
  phenytoin
• Tinnitis/Vertigo Aspirin, furosemide,
  ethacrynic acid
• Psychomotor retardation Neuroleptics,
  tricyclics, benzodiazepines, antihistamines

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DRUG-INDUCED GERIATRIC SYNDROMES

• Incontinence Anticholinergics,
  alpha-antagonists, diuretics, hypnotics/sedatives
  
• Delirium Anticholinergics, cimetidine
• Gait and Balance Problems - Long-acting
  benzodiazepenes, alcohol, antipsychotics

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GUIDELINES FOR PROPER DRUGPRESCRIBING AND USE

• Start low and go slow
• Consider
• The unique dosage requirements of the patient
• The patients lifestyle
• Quality of life
• Pre-existing conditions
• Risk vs benefit of drug therapy
• Financial impact of drug therapy
• Be aware of and monitor for adverse drug
  reactions and drug interactions

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The following descriptions of geriatric patients
include two or more medications being prescribed
for each patient (A through H). A. 93-year
old woman with fall (HCTZ, chlordiazepoxide,
alcohol) B. 76-year old man with Parkinson
disease symptoms (HCTZ, metoclopramide) C.
80-year old hospitalized woman with confusion
(diphenhydramine, amtryptiline) D. 72-year old
woman with atrial fibrillation (beta blocker,
levo-thyroxine) E. 65-year old woman with kidney
infection (gentamicin, lasix) F. 75-year old
woman with myocardial infarction (HCTZ,
simvastatin) G. 89-year old man with recent hip
fracture (cimetidine, diphenhydramine) H. 82-year
old woman with urinary incontinence (prazosin,
chlorpropamide)
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Put the letter of the one patient description
that best matches the numbered options listed
below. (Letters may be used more than once).
______1. CNS side-effect of GI drug
______2. Patient with
side-effect of an alpha blocker ______3.
Needs to be on a beta blocker
______4. TSH level needs to be checked
______5. Patient
at-risk for hyponatremia
______6. Patient at risk for oto-toxicity
______7. Long-acting drug
complication ______8.
Anti-cholinergic side-effect ______9. Patient
at-risk for delirium
______10. Drug levels need to be checked