Geriatrics

Question 1

Absorption

Answer 1

• Drugs absorbed slower in elderly due to decrease gastric secretions and decrease in GI motility (fewer # of enterocytes resulting in less absorptive capacity)
• Depends on lipid solubility of the drug

Question 2

Distribution

Answer 2

• increase potential for toxicity and/or potency
• -decrease in lean body mass/muscle, increase in fat stores
• -decrease in total body water (10-15%). Impacts drugs bound to albumin (dilantin)
• -higher free serum levels (dig, phenytoin, warfarin)

Question 3

Metabolism

Answer 3

• Decrease in hepatic blood flow and metabolism

- decrease in 1st pass metabolism resulting in higher blood levels (BB, antiarrhymics, estrogens, nitrates)

Question 4

Excretion

Answer 4

-renal decline is most significant change in affecting medications

Question 5

Examples of decreased renal clearance requiring dose/frequency adjustment

Answer 5

• Abx: PCNs, sulfas, fluroquinolones, cephalosporins-dose less
• BB: Atenolol
• Cardiac: Dig, quinidine-u
• H2 blockers: famotidine
• others: lithium, allopurinol, quinine, gabapentin, fexofenadine
• —<30mL/min: not recommended to give metformin, xarelto, enoxaparin

Question 6

BEERS criteria

Answer 6

-used for older adults ?65 y/o in all ambulatory, acute and institutional care settings

Question 7

STOPP/Start criteria

Answer 7

• screening tool of older persons potentially inappropriate medications
• Applications to acutely ill elderly patients

Question 8

Medications to avoid/monitor

Answer 8

• Benzodiazepines: Lorazepam, Alprazolam (Xanax)-long acting
• Anticholinergics: Amitriptyline (TCA), diphenhydramine, hydroxyzine, cyclobenzaprine (flexeril)-blurred vision, falls
• Digoxin >0.125 mg day
• Older sulfonylurea antihyperglycemics: Glipizide, glyburide
• Hypnotics: CNS depressants, (Ambien)

Question 9

Meds of concern (Warfarin)

Answer 9

Anticoagulants-Warfarin (metabolism of CYP2C9, effects are accentuated).

• -Warfarin and NSAIDS-peptic ulcer
• -Warfarin and ASA
• -Warfarin/antibiotics (metronidazole, fluconazole, sulfamethoxazole/TMP)
• –consider using newer direct acting anticoagulants: Apixaban, rivaroxaban-less variability and no INR monitoring-Expensive

Question 10

Meds of concern (Thiazides/loop diuretics, antihypertensives, antiarrhythmics, digoxin, diabetes medications)

Answer 10

• Thiazides or Loop: HCTZ, Lasix will have a weaker diuretic effects, consider increasing dose
• –caution that increased dose may increase dehydration and glucose, watch K
• -Antihypertensives: avoid BB with lung disease, avoid vasodilators w/ orthostatic problems
• -Antiarrhytmics-Start low
• Dig: clearance is 50% decreased, max doses 0.125mg/daily-check levels
• -Diabetes meds: Sulfonylureas-prolonged clearance: Hypoglycemia

Question 11

Common anticholinergic effects seen in elderly

Answer 11

• CNS: Lethargy, decrease mentation, confusion, irritability, restlessness
• Optic: dry eyes, blurred vision
• Cardiac: tachycardia
• Respiratory: dry mucus membranes
• GI: Slowed motility, decreased secretions
• GU: decreased tone-incontinence
• Glandular: Inhibited-decrease sweat

Question 12

Suspicious Agents that increase risk of falls

Answer 12

• Anticholinergics-impaired vision
• Narcotics-impaired balance/gait and cognition
• Antihypertenive and some antipsych meds-orthostatis
• Diuretics-fluid shifts
• Benzos-impaired cognition