Polypharmacy & Prescribing in the Elderly

Polypharmacy & Prescribing in the Elderly

Dr. Russell O'Brien - Consultant in Acute Medicine
UNIVERSITY OF MEDICAL EXETER SCHOOL

Learning Outcomes

  • Define Polypharmacy: Understanding multiple medications, typically 5 or more, taken by a patient.
  • International Issue: Recognize the significance of polypharmacy as a global concern due to increasing elderly populations and drug interactions.
  • Benefits and Risks: Identify the advantages of prescribing multiple medications versus the potential for adverse drug reactions (ADRs).
  • Avoiding Polypharmacy: Methods to minimize polypharmacy, especially in elderly patients.
  • Usual Suspects: Awareness of medications that frequently cause issues in older adults.

Prescribing Statistics in the Elderly

  • Polypharmacy Prevalence: 20% of individuals over 65 take five or more medications.
  • Admissions Due to ADRs: 20% of hospital admissions in the elderly are related to adverse drug reactions.

Change in UK Over-65 Population (1975-2045)

  • Projected Growth:
    • 1975: 14% under 15s, 18% aged 65 and above.
    • 2015: 20% under 15s, 25% aged 65 and above.
    • 2045: Anticipated 25% aged 65 and above, escalating healthcare needs.
  • Source: Office for National Statistics

Clinical Case Review

  • Patient Information: 73-year-old male, history of acute delirium, cognition issues, multiple health conditions, and medications.
  • Past Medical History: Conditions include osteoarthritis, diabetes, hypertension, TIA, and cognitive impairment.
  • Medication Review:
    • List of Medications: Includes Aspirin, Timolol, Clopidogrel, Donepezil, etc.
  • Clinical Symptoms: Confusion, drowsiness, and mobility issues reported by family.

Complexity in Prescribing for the Elderly

  • Philosophical Insight: "Doctors are men who prescribe medicines of which they know little…" - Voltaire
  • Review of drug interactions leading to adverse events and complex care situations.

Pharmacokinetic Changes in the Elderly

  1. Absorption: Decreased gastric blood flow and mucosal atrophy leading to altered drug metabolism.
  2. Distribution:
    • Increased body fat and decreased muscle mass.
    • Lower plasma proteins affecting drug availability.
  3. Metabolism:
    • Reduced hepatic blood flow and enzyme activity impacting drug clearance.
  4. Excretion:
    • Decline in renal function impacting drug elimination rates, GFR decreases 50% from age 50 to 90.

Pharmacodynamic Changes in the Elderly

  • Altered Sensitivities: Up and down regulation of receptors can change drug efficacy.
  • Homeostasis Impairments: Issues with thermoregulation, blood pressure control, and fluid balance.

Causes of Polypharmacy in Elderly Patients

  • External Factors:
    • Guidelines and pressure from pharmaceutical companies.
  • Internal Factors:
    • Therapeutic enthusiasm leading to excessive prescribing without adequate review.
  • Prescribing Cascade: Treatment of one condition inadvertently worsens another requiring additional medications.

Consequences of Polypharmacy

  • Patient Level: Confusion, high pill burden, poor treatment adherence, significant ADRs.
  • Population Level: Increased drug resistance, high healthcare costs, and overall complexity of care.

Strategies to Reduce Polypharmacy

  1. Regular medication reviews and audits, especially for patients over 75.
  2. Determine the appropriateness of medications considering risk vs. benefit.
  3. Engage patients in understanding their treatment and improve concordance.
  4. Consider non-drug treatment options where applicable.
  5. Focus on quality of life and treat the underlying causes not just symptoms.

The Usual Suspects: Problematic Medications

  • High-Risk Medications include:
    • Anti-arrhythmics (e.g., Digoxin)
    • Diuretics (e.g., Furosemide)
    • Hypoglycemic agents (risk of hypoglycemia)
    • Anticoagulants (e.g., Warfarin)
    • CNS drugs (e.g., antidepressants, antipsychotics)
  • Concerning Outcomes: Increased likelihood of adverse reactions leading to complications.

Summary of Key Points in Polypharmacy

  • Understanding dynamic changes in aging affects drug therapy.
  • Importance of identifying and addressing the issues caused by polypharmacy.
  • Implementing actionable strategies for minimizing polypharmacy in clinical practice will improve patient care outcomes.

References

  • Evidence-based guidelines from NICE
  • Relevant works by Voltaire and Benjamin Franklin regarding medical practices.