Week 3: Geriatric Patients

Question 1

Pharmacokinetic - absorption changes in older adults

Answer 1

• decreased acid production - decreased absorption of acidic drugs
• delayed gastric emptying - reduced blood flow to GI tract - slowed GI absorption

Question 2

Distribution changes in older adults

Answer 2

• increased fat stores - lipophilic drugs have higher distribution and longer half-lives
• decreased body water - hydrophilic drugs have lower distribution and high plasma levels
• decreased serum albumin levels - decreased drug-protein binding - increased free drug for high protein binding drugs

Question 3

Metabolism changes in older adults

Answer 3

• decreased hepatic blood flow - decreased first pass effect - decreased metabolism of drugs that have high first pass breakdown - decreased effectiveness of prodrugs that require first pass
• decreased CYP450 system function - decreased metabolic clearance of drugs - decreased metabolism of some drugs - altered drug-drug interactions

Question 4

Excretion changes in older adults

Answer 4

• decreased renal mass and GFR - decreased tubular secretion - decreased renal clearance of drugs - may require dosage adjustment - creatinine clearance and GFR are more accurate than sr. creatinine
• serum creatinine comes from muscle breakdown - elderly patients have decreased muscle mass so serum creatinine is not an accurate indicator of renal function

Question 5

Pharmacodynamic changes in older adults

Answer 5

• reduced homeostatic mechanisms
• altered receptor sensitivity
• increased sensitivity to drugs

Question 6

Factors that put geriatric patients at higher risk for ADRs

Answer 6

• nonadherence: Intentional (too expensive) and unintentional (forgetfulness)
• unsafe practices - unable to see or identify which pill is which
• mixing OTC and herbal medicines with prescription drugs
• polypharmacy - drug-drug interactions - overlapping or duplicating medications

Question 7

Important to assess in geriatric patients

Answer 7

Cognitive functioning - ability to identify their medications - to understand why and how they are to take them

Question 8

General principles for Prescribing to Older Adults

Answer 8

• collect a complete drug history - revisit at least every 6 months
• avoid a drug if benefit is only marginal
• evaluate drug list for duplications
• review drug list for ADRs and query the patient
• prescribe nonpharmacological treatments whenever possible
• Start low and go slow
• do not give a drug to treat a side effect of another drug