Drugs and the Elderly

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Im a walking drugstore!
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Im a walking drugstore!Polypharmacy
Dr J Puxty Queens University
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Main Themes

• Polypharmacy
• Adverse Drugs Reactions
• Pharmacokinetics
• Pharmacodynamics
• Compliance
• Principles of Medication Review

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Polypharmacy

• Seniors accounts for 25 prescriptions
• Drugs account for 15 Health Care costs
• Only 15 of community elderly take no prescribed
  medications
• Over 75 year old take on average nearly 3
  prescribed medications and 1.5 across the counter
  meds daily!
• In surveys of community elderly serious
  comprehension problems in 12-16

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Across the Counter Medications

• Surveys report an average of 1.5
  pharmacologically active substance per day
• Particular areas of concerns are NSAIs, CNS
  depressants, Laxatives etc
• Includes alcohol!

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Day Hospital Survey

• Average number of active medications ranges from
  5.5-8.3 per day
• Serious comprehension problems rise to 37
• Questionable indication for use in at least 27
• Attendance at DH resulted in only 0.8 No. of meds
  reduction (8.3 -gt 7.5) but nearly 50 change in
  type or dose used.

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Common Drugs Prescribed

• Anti-hypertensives 15-25
• Hypnotics 23 of women over 65 years
• Diuretics 15-25
• NSAIs 10-15
• Digoxin 10

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Adverse Drug Reactions
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Adverse Drug Reactions

• Unfortunately very common
• Suggested contribute to at least 10-15 hospital
  admissions
• Likelihood increases with number of medications
• Includes complications with serious functional
  consequence eg falls -gt Hip

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Why do we prescribe?

• Increasing age associated with higher prevalence
  of many diseases
• Need to treat
• High volume of visits
• prn as required orders become regular
  prescriptions
• Inappropriate belief patient will go elsewhere
  for meds

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Pharmacokinetics and Aging

• Absorption - gastric pH higher, decreased
  motility and absorption
• Distribution - reduced total body water, proteins
  and lean body mass, and increased total body fat
• Metabolism - hepatic oxidative pathways impaired
  (benzodiazepines) and P-450 (B-blockers, TCAs,
  verapamil)
• Excretion - reduced GFR and change in tubular
  function (aminoglycosides, lithium, digoxin)

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• Low Body Water -gt reduced vol. of dist. for polar
  drugs eg. Aminoglycocides, Digoxin
• High Fat Stores -gt increased vol. of dist. for
  lipid soluble drugs eg. Phenytoin, Diazepam,
  Flurazepam

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Pharmacokinetics and Aging

• Absorption - gastric pH higher, decreased
  motility and absorption
• Distribution - reduced total body water, proteins
  and lean body mass, and increased total body fat
• Metabolism - hepatic oxidative pathways
  (benzodiazepines and P-450 (B-blockers, TCAs,
  verapamil)
• Excretion - reduced GFR and change in tubular
  function (aminoglycosides, lithium, digoxin)

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Pharmacodynamics(effect of drugs at target site)

• No generalization regarding receptor numbers or
  affinity or hormone levels
• Examples of changes are insulin receptors, Beta
  receptors and heart, Ach receptors and colon

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Factors modifying compliance
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Factors modifying compliance

• Comprehension
  instructions
  labels
  cognition
• Dexterity
• Number of medications
• Side-effects

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Principles of Medication Review

• Obtain a complete drug history from patient,
  family, physicians and others
• Review each medication for indication,
  therapeutic goal and compliance
• Review patient factors - personal goals,
  cogniton, vision, dexterity, monitoring and
  pharmacist
• Consider medication safety and efficacy
  individually and within total picture

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Management of Agitation
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Management of Agitation

• Characterise behaviour
• Careful Medical Review (7 Is)
• Assess predisposing/aggravating factors
• Establish Neuropsychiatric diagnosis
• Optimise psychosocial status
• Education of caregivers
• Behaviour management (patient others)
• Consider symptomatic pharmacotherapy

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Causes of Agitation (seven Is)

• Iatrogenic
• Infection
• Injury
• Illness (pre-existing) exacerbation
• Inconsistency of environment
• Inconsistemt caregiving
• Is patient depressed

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Symptomatic Pharmacotherapy

• Benzodiazepines (oxazepam, lorazepam)
• Buspirone
• Neuroleptics (haldol, loxapine, rispiridone)
• Anticonvulsants (carbamazipine, valporate)
• Serotinergic agents (trazdone, 5 HT uptake
  blockers)
• Lithium
• B-blockers
• Selegiline