Pharmacology In Older People Flashcards
Notes from lecture
What is frailty?
Clinically recognised state of Increased vulnerability. Results from ageing associated with a decline in the body’s physical and psychological reserves
What is the name of the tool for assessing frailty in hospital?
Rockwood Score
What are the absorption process changes in older people affecting absorption? (Making things take longer)
Inc gastric pH and gastric emptying time
Reduced saliva, gastric acid secretion, surface area, GI motility and active transport mechanism
What are the physiological changes in an older person affecting distribution? (Transportation of drug in the blood stream to various tissues)
Reduced
cardiac output,
renal and hepatic blood flow (reduction in metabolism and excretion)
serum albumin (Inc free drug circulating, more risk of s/e and toxicity)
total body water (may lead to higher conc of water soluble drugs, so need lower dose
Increased
peripheral vascular resistance
adiposed body fat tissue (lipid sol drugs inc their volume of distribution, staying in system for longer, so accumulation and s/e occur; may have lack of effect but stay in body longer to cause slow distribution/excretion)
What factors change in older people affect metabolism?
Reduced
Microsomal hepatic oxidation - enzyme levels
First pass effect
Increased
Steady state levels - drug not metabolised so higher levels available
Half life - last longer as not metabolised
Level of active metabolite
What is a pro-drug? (Check for pro-drugs on EMC)
Manufactured to be protected in the system, but needs metabolising in the liver to be useful to the body
Codeine needs metabolising in the liver to become morphine
Wouldn’t be effective in chronic liver disease patients so wouldn’t be used.
What changes occur in excretion for older people?
Reduced renal excretion - always assume older pts will have some level of renal impairment
Use cockroft/Gault formula to change eGFR to appropriate
What is the calculator for changing the eGFF to appropriate for older/renal impaired patients
Cockcroft/Gault formula
Find in renal prescribing section at beginning of Bnf
Pharmacodynamic changes in older people?
Inc sensitivity to medicines
More sensitive CBS
Toxic GI effects
Balance easily affected
What is iatrogenic disease?
Disease caused by drugs
What are common adverse reaction in elderly patients?
- anticholinergic effects (dry mouth, dizziness, constipation, blurred vision)
- confusion (caused by most drugs)
- falls (associated with ADRs can be fatal)
- iatrogenic disease-symptoms (symptoms caused by meds)
- anticholinergic burden (accumulation effect)
