Intro to Geriatrics - Block 4 Flashcards
How do you assess geriatric status?
Describe the absorption of geriatric?
- Decreased gastric acid
- SLower GI motility
- Delayed gastric emptying
Medications:
* Passive diffusion -> less likely to be affected
* Active transport -> more likely to be affect
* Drugs affected by gastric pH are affected in a small proportion of adults
Describe distribution in geriatrics?
- Augmented blood flor
- Plasma protein binding
- Body composition
- CNS permeability
Describe the metabolism in geriatric?
- FLow limited
- Capacity limited
How does flow-limited metabolism affect drugs?
- Affects drugs dependent on high intrinsic clearance
- High intrinsic clearance is due to grug’s structure mimicking endogenous agents
- Poor metabolism of these drugs is due to decreased hepatic perfusion
Examples: metoprolol, propranolol, lignocaine, nifedipine, fentanyl and verapamil
How does capacity limited metabolism affect drugs?
- Affects drugs that are dependent on low intrinsic clearance
- Enzymatically driven and largely affected by protein binding
Examples: reduced (lorazepam, piroxicam, warfarin), increased (ibuprofen, naproxen, phenytoin) or unchanged (diazepam, temazepam and valproic acid)
Describe phase metabolism in geriatrics?
Phase 1 metabolism is usually more affected by hepatic dysfunction as compared to phase 2
* Reduced phase II dues to inflammation
How is elimination affected by age?
Age related deterioration must be evaluated but decrease in renal function doesnt directionally correspond to age
Decreased muscle mass can affect CrCl calculations; GFR can be skewed by high protein intake
Describe the PK parameters in geriatrics?
Describe the PD changes in elders?
- Changes in concentrations of the drug at the receptor
- Changes in receptor numbers
- Changes in receptor affinity
- Post receptor alterations
- Age-related impairment of homeostatic mechanisms
How might cause CNS changes in elders?
- Changes in brain size and weight
- Increased BBB penetration
- Dopaminergic alterations
What are drugs that are affected by CV changes?
Calcium channel blockers: increased hypotensive and bradycardic effects
β-blockers: reduced blood pressure response
Diuretics: reduced effectiveness
Warfarin: increased risk of bleeding
What is goal of pharmacotherapy in elders?
Cure or palliate disease and enhance HRQOL
What are HRQOL considerations in elders?
- Improvements in physical functioning
- Psychological functioning
- SOcial functioning
- Overall health
What is the definition of polypharm?
- ≥5 or more meds
- Multiple medications that are used for the same indication
- Unnecessary drug use or use without indications
Contributing factors: comorbidities