Principles of Drug Therapy in Geriatric Patients: A 1-Hour Educational Presentation

Slide 1: Opening Case & Core Principle

The fundamental principle of geriatric pharmacotherapy is to optimize benefit, minimize harm, and enhance quality of life through systematic medication management that accounts for age-related physiological changes and multimorbidity. 1

Case Presentation: An 82-year-old woman presents with 12 medications including warfarin, lisinopril, metformin, and diphenhydramine. She has had two falls in the past month and reports confusion.

Slide 2: The "5 R's" of Geriatric Prescribing

Achieving optimal outcomes requires the right medication at the right dose administered to the right person at the right time for the right duration. 1

Right Medication: Use validated criteria (Beers, STOPP/START) to identify potentially inappropriate medications 1
Right Dose: Account for reduced renal/hepatic clearance and altered distribution 1
Right Person: Consider life expectancy, functional status, and goals of care 1
Right Time: Simplify to once or twice daily dosing whenever possible 2
Right Duration: Reassess at every care transition and periodically in outpatients 1

MCQ #1: A 78-year-old man with CrCl 25 mL/min is prescribed lisinopril 20mg daily. What adjustment is required?

A) No adjustment needed
B) Reduce to 10mg daily
C) Reduce to 5mg daily and monitor closely
D) Contraindicated

Answer: C - Dose adjustment required for CrCl ≤30 mL/min 3

Slide 3: Age-Related Pharmacokinetic Changes

Aging fundamentally alters drug absorption, distribution, metabolism, and elimination, increasing adverse drug event risk 7-fold compared to younger patients. 4, 5, 6

Distribution Changes:

Decreased water content: Reduces volume of distribution for hydrophilic drugs (e.g., digoxin), leading to higher plasma concentrations 6
Increased body fat: Increases volume of distribution for lipophilic drugs (e.g., diazepam), prolonging half-life 4, 6

Metabolism & Elimination:

Reduced renal clearance: Treat elderly as renally insufficient; dose adjustment mandatory for renally cleared drugs 6, 3
Hepatic metabolism: Blood flow-limited metabolism (high extraction drugs) is reduced; capacity-limited metabolism usually preserved 6
More pronounced in frail/malnourished patients 6

Slide 4: Age-Related Pharmacodynamic Changes

Elderly patients exhibit increased end-organ sensitivity and reduced homeostatic mechanisms, resulting in stronger drug effects and higher adverse event rates even at therapeutic plasma concentrations. 1, 6

Enhanced Drug Effects:

Postural hypotension with antihypertensives (reduced baroreflex response) 1, 6
Bleeding complications with anticoagulants (warfarin shows greater PT/INR response in patients ≥60 years) 7
Hypoglycemia with antidiabetics 1, 6
CNS effects: Increased sensitivity to opioids, benzodiazepines, anticholinergics 1, 6
GI irritation with NSAIDs 6

MCQ #2: An 85-year-old on warfarin has an INR of 3.8 (target 2-3). What explains this?

A) Medication non-adherence
B) Age-related enhanced anticoagulant response
C) Drug interaction only
D) Laboratory error

Answer: B - Patients ≥60 exhibit greater PT/INR response 7

Slide 5: The Polypharmacy Crisis

Polypharmacy (≥5 medications) increased from 24% in 2000 to 39% in 2012 among older adults and is the strongest predictor of prescribing problems, adverse drug events, hospitalizations, and mortality. 1, 2

Consequences:

Drug-drug interactions: Occur in 27-31% of elderly on multiple medications 2
Prescribing cascade: Drug side effects misidentified as new conditions, triggering additional prescriptions 1, 8
Therapeutic omissions: Essential medications overlooked in complex regimens 1
Functional decline and falls 2

Cardiovascular Polypharmacy:

15 of top 20 medications in elderly are cardiovascular drugs 1
Statin use: 50.1%, antiplatelet agents: 43.0%, ACE inhibitors: 30.4% 1

Slide 6: Systematic Medication Review Framework

Comprehensive medication reviews at every care transition reduce hospitalizations and must address nine key drug therapy problems. 1

The 9-Point Assessment:

Indication without drug: Undertreated conditions (e.g., CAD without statin) 1
Drug without indication: Medications continued without clear benefit 1
Ineffective drug: Not achieving therapeutic goal 1
Dosage too low: Subtherapeutic dosing 1
Adverse drug reactions: Identify and eliminate causative agents 1
Dosage too high: Risk of toxicity, especially with renal/hepatic impairment 1
Drug-drug interactions: Review all medications including OTC and supplements 1
Nonadherence: Assess using validated tools (Morisky Scale) 2
Monitoring gaps: Ensure appropriate lab monitoring (TSH, INR, glucose) 1

MCQ #3: A patient on warfarin, aspirin, and newly started NSAID presents with melena. This represents:

A) Drug without indication
B) Dosage too high
C) Drug-drug interaction
D) Adverse drug reaction

Answer: C & D - Both drug-drug interaction and ADR 1

Slide 7: High-Risk Medications to Deprescribe

Deprescribing high-risk medications has the same clinical importance as initiating appropriate therapy and directly reduces morbidity and mortality. 1, 2

Priority Targets (Beers Criteria):

1. Anticholinergics:

Diphenhydramine, cyclobenzaprine, oxybutynin cause cognitive impairment, falls, urinary retention, constipation 1
Anticholinergic burden associated with functional decline 1
Action: Discontinue or switch to alternatives with lower anticholinergic properties 1

2. Hypoglycemic Agents:

Sulfonylureas and short-acting insulin are leading causes of ED admissions 1
Action: Relax A1c goals, deintensify regimens, switch to basal insulin 1

3. Benzodiazepines:

Associated with cognitive impairment, falls, dependence 8
Action: Taper by 25% every 1-2 weeks 2

4. Antipsychotics:

Action: Systematic review and gradual discontinuation with behavioral monitoring 2

Slide 8: Deprescribing Algorithm

For patients with advanced disease or limited life expectancy, benefits are unlikely to offset risks when time to benefit exceeds estimated survival. 1, 2

Step-by-Step Approach:

Step 1: Identify Targets

Medications causing immediate harm 2
High-risk medications (Beers/STOPP criteria) 1
Medications without long-term indication 2
Preventive medications when life expectancy < time to benefit 2

Step 2: Consider Time Horizon

Statins: Discontinue if life expectancy < 2-3 years 2
Diabetes medications: Focus on symptom control vs. prevention 1, 2
Benefits may persist after discontinuation of some long-term therapies 1

Step 3: Implement Safely

Taper medications with withdrawal risk 2
Monitor for symptom recurrence 2
Avoid prescribing cascade 8

MCQ #4: An 88-year-old with dementia, CHF, and 6-month prognosis is on atorvastatin. Best action?

A) Continue for cardiovascular protection
B) Increase dose for aggressive lipid control
C) Discontinue - time to benefit exceeds life expectancy
D) Switch to different statin

Answer: C - Discontinue when life expectancy < time to benefit 2

Slide 9: Addressing Adherence Barriers

Concordance between clinician and patient leads to greater motivation, persistence, and adherence, improving outcomes and preventing hospitalizations. 1, 2

Systematic Assessment:

Use validated tools: Morisky Scale to identify barriers 2
Complex dosing schedules: Simplify to once or twice daily 2
Cost barriers: Address financial constraints 2
Side effects: Identify and manage proactively 2
Cognitive impairment: Use assessment tools (MMAA, DRUGS, HMS, MedMaIDE) 1

Interventions That Work:

Reminder systems and education have varying effects 1
Self-management education improves self-efficacy and adherence 1
Medication management support reduces hospitalizations 1

Slide 10: Special Considerations for Specific Drugs

Warfarin in Elderly:

Contraindicated in unsupervised senile patients 7
Lower initiation and maintenance doses required 7
Patients ≥60 years exhibit greater PT/INR response 7
Caution in any situation with added hemorrhage risk 7

ACE Inhibitors (Lisinopril):

Dose adjustment required for CrCl ≤30 mL/min 3
No adjustment needed for CrCl >30 mL/min 3
Elderly more sensitive to hypotensive effects 1
In GISSI-3 trial, 4.8% of patients ≥75 years discontinued due to renal dysfunction vs. 1.3% in younger patients 3

MCQ #5: Which statement about warfarin in elderly is FALSE?

A) Lower doses are recommended
B) Greater PT/INR response expected
C) Same dosing as younger patients is appropriate
D) Contraindicated in unsupervised senile patients

Answer: C - Lower doses are required 7

Slide 11: Care Transitions as Critical Intervention Points

66% of hospitalized older adults use potentially inappropriate medications, and 85% continue them at discharge, making transitions mandatory reassessment opportunities. 1

Key Transition Points:

Hospital admission: Reevaluate all medications 1
ICU transfer: Reassess appropriateness 1
Hospital discharge: Critical opportunity to deprescribe 1
Periodic outpatient reviews: Ongoing reassessment 1

What to Reassess:

Treatment complexity and adherence 1
Medication appropriateness for current status 1
Alignment with goals of care 1
Functional status and support needs 1

Slide 12: Team-Based Approach

Successful polypharmacy management requires coordination among multiple prescribers, clinical pharmacists, nursing staff, and patient/family engagement. 2, 8

Team Roles:

Clinical Pharmacists:

Comprehensive medication reviews 1
Medication ward rounds reduce errors 1
Computer-assisted and barcode-controlled dispensing 1
Interaction screening 8

Nursing Staff:

Medication administration verification 1
Monitoring for adverse effects 2
Patient education 1

Multiple Prescribers:

Coordination crucial to prevent duplication 2, 8
Unified prescription forms improve communication 1

Patient & Family:

Collaborative decision-making 1
Supervised administration when needed 9

Slide 13: Practical Implementation Strategies

Uniform prescription systems and structured protocols reduce medication errors, which are particularly problematic in elderly patients with cognitive impairment, renal insufficiency, and polypharmacy. 1

System-Level Interventions:

Uniform prescription forms: Single sheet contains all patient information, avoids transcription errors 1
Limit abbreviations: Reduce misinterpretation 1
No verbal prescriptions: Require written orders 1
Daily prescription review: Identify drug-drug interactions and ADRs 1
Periodic audits: Evaluate appropriateness 1

Patient-Level Tools:

Pill organizers and dispensing devices 2
Visual aids for impaired vision 10
Supervised administration for cognitive impairment 9
Caregiver storage of medications when appropriate 9

MCQ #6: Which intervention has strongest evidence for reducing medication errors?

A) Verbal prescription protocols
B) Clinical pharmacist involvement in medication process
C) Patient self-management only
D) Increasing number of prescribers

Answer: B - Pharmacist involvement reduces errors 1

Slide 14: Avoiding Common Pitfalls

Pitfall #1: The Prescribing Cascade

Drug side effects misidentified as new conditions lead to additional prescriptions, worsening polypharmacy. 1, 8

Example: Metoclopramide causes parkinsonism → carbidopa/levodopa prescribed
Prevention: Always consider drug-induced causes before adding new medications 8

Pitfall #2: Ignoring Renal Function

Declining renal function requires dose adjustments to minimize toxicity risk. 2, 3

Action: Calculate CrCl for all elderly patients, adjust doses accordingly 3

Pitfall #3: Applying Guidelines Without Context

Guidelines assume constant benefits/risks over time and exclude very elderly, frail, and multimorbid patients. 1

Reality: Limited evidence for patients ≥75, with multimorbidity, or frailty 1
Action: Individualize based on functional status and goals of care 1

Pitfall #4: Overlooking Supplements

Vitamins and supplements contribute to medication burden, cost, side effects, and interactions. 1

Action: Review and simplify; discontinue non-contributive supplements except recommended ones (vitamin D) 1

Slide 15: Case Resolution

Returning to our 82-year-old with 12 medications, falls, and confusion:

Systematic Review Reveals:

Diphenhydramine: High anticholinergic burden causing confusion 1
Warfarin: INR 3.8 (age-related enhanced response) 7
Metformin: CrCl 28 mL/min - dose adjustment needed 2
Multiple supplements: Non-contributive 1

Actions Taken:

Discontinued diphenhydramine → confusion improved 1
Reduced warfarin dose → INR stabilized 7
Adjusted metformin dose for renal function 2
Eliminated 4 supplements → simplified regimen 1
Consolidated to twice-daily dosing → improved adherence 2

Outcome: Falls ceased, cognition improved, medication burden reduced from 12 to 7 essential medications.

MCQ #7: What was the PRIMARY cause of this patient's falls?

A) Warfarin overdose
B) Anticholinergic burden from diphenhydramine
C) Metformin toxicity
D) Polypharmacy alone

Answer: B - Anticholinergics cause cognitive impairment and falls 1

Slide 16: Take-Home Messages

Core Principles:

Optimize benefit, minimize harm, enhance quality of life - this is the overarching goal 1
Apply the 5 R's systematically: Right medication, dose, person, time, duration 1
Account for age-related changes: Reduced clearance, altered distribution, enhanced sensitivity 1, 6
Polypharmacy is dangerous: ≥5 medications dramatically increases adverse events 1, 2
Deprescribing is therapeutic: Same importance as starting appropriate therapy 2
Target high-risk medications: Anticholinergics, hypoglycemics, benzodiazepines, antipsychotics 1, 2
Reassess at every transition: Hospital admission, discharge, periodic outpatient reviews 1
Consider time horizon: When life expectancy < time to benefit, deprescribe preventive medications 1, 2
Simplify regimens: Once or twice daily dosing improves adherence 2
Use team-based approach: Pharmacists, nurses, multiple prescribers, patient/family 2, 8

Final MCQ Challenge:

MCQ #8: An 80-year-old with CHF, diabetes, CKD (CrCl 25), and 18-month prognosis takes 14 medications including atorvastatin, glyburide, diphenhydramine, and lisinopril. What is the HIGHEST priority intervention?

A) Add another antihypertensive for better BP control
B) Discontinue atorvastatin and glyburide; adjust lisinopril dose; stop diphenhydramine
C) Continue all medications as prescribed
D) Increase statin dose for aggressive lipid control

Answer: B - Deprescribe statin (time to benefit > life expectancy), switch glyburide (high hypoglycemia risk), adjust lisinopril (renal impairment), stop diphenhydramine (anticholinergic) 1, 2, 7, 3

Remember: In geriatric pharmacotherapy, less is often more. Every medication must justify its continued use by providing meaningful benefit that outweighs harm within the patient's remaining life expectancy and goals of care. 1, 2

What are the principles of drug therapy in geriatric patients?

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