Pharmacology and the Elderly Flashcards
What does ADME stand for?
Absorption
Distribution
Metabolism
Excretion
What environment do acidic drugs require for absorption?
acidic environment
Give some examples of acidic drugs?
phenytoin
aspirin
penicillins
What environment do basic drugs require for absorption?
basic
Give some examples of basic drugs?
diazepam
morphine
pethidine
Why are basic drugs more prone to cause delirium?
they cause a change in pH
Which type of drug is absorbed more due to increased gastric pH? and why?
basic
increased gastric pH decreases small bowel surface area
Do elderly people have more Alpha-1 or albumin?
Alpha 1
What does albumin bind to?
acidic drugs
What does alpha-1 bind to?
basic drugs
Why do elderly absorb more basic drugs?
elderly have more Alpha-1 so bind to more basic drugs
Why do elderly people induce a longer half live in lipophillic drugs?
they have more fat than muscle which increased the volume of distribution of lipophillic drugs
Give an example of a lipophillic drug?
diazepam
anaesthetics
Give an example of a hydrophillic drug?
digoxin
lithium
What are the characteristics of a hydrophillics drugs volume of distribution and half life?
smaller volume of distribution
short half life
Why is hepatic metabolism often reduced in elderly?
decreased liver size
decreased blood flow
diseased liver
How does the therapeutic window change as you age?
gets narrower
How does renal metabolism change in elderly?
lower GFR due to decreased size, tubular secretion and renal blood flow
What should you always prescribe alongside an opioid in elderly?
lactulose or senna
What must you do if you presrcibe long term steroids in elderly?
give osteoporosis prevention
monitor BG in those with diabetes
What must elderly patients never take when taking levothyroxine?
calcium
What are the side effects of anticholinergic drugs?
long term risk of developing dementia
also causes confusion, hallucinations, tachycardia, falls, constipation, dizziness, blurred vision and urinary retention
What common side effect does calcium cause?
GI upset