ADME Flashcards
what is a drug?
a chemical substance, which, when taken, affects some physiological function in the body
the active ingredient of a medicine
why do we administer drugs?
to maintain or restore the body’s homeostasis i.e to restore body function
what is pharmacodynamics?
what the drug does to the body i.e body provides a response
what is pharmacokinetics?
what the body does to the drug (ADME)
for a drug to produce a response where must it reach?
site of action
name the 6 routes of administration
1 oral/ rectal 2 percutaneous 3 intravenous 4 intramuscular 5 intrathecal 6 inhalation
what are the 3 responses a drug can produce?
1 therapeutic effect
2 toxic effect
3 side effect
define absorption
Extent to which the INTACT drug is absorbed from gut lumen into portal circulation
name the 4 ways in which a drug can pass through a biomembrane
1-Passive Diffusion … most common
2– Carrier Mediated / Active Transport
3– Convective Absorption
4– Ion-Pair Absorption
define biotransport
The translocation of a solute from one side of a biological barrier to the other side in the intact form
what is the general thickness of a lipid bilayer
(typically~50 Ǻ thick)
what is a membrane made up of?
phospholipids
• Protein, glycoprotein and cholesterol
what does bioavailability depend on?
–how well the drug is absorbed
– Depends on how much drug is metabolised by the liver
what are the metabolising enzymes in the gut wall
Main Cytochrome P450 is CYP3A4
Cytochrome P450 activity in intestinal
epithelium relative to liver (%)