B6 Flashcards
absorption
how the drug enters the system and circulation
distribution
how drugs are dispersed in the tissues and fluids throughout the body
transcellular transport
across semipermeable membranes
the rate of passage depends on
pressure
concentration
temp of molecules on either side
permeability of the membrane
permeability depends on
size and solubilty of the solute
routes of administration
topical
enteral
parental
what does absorption determine
bioavailability
bioavailabilty
the fraction of drug that reaches the bloodstream unaltered
absolute bioavailability
availability of the active drug in circulation after non iv administration
equation of absolute bioavailability
area under the curve non iv/ auc iv
relative bioavailability
bioavailability of drug compared to another formulation of the same drug
factors influencing absorption
rate of gastric emptying Gi blood flow stomach acid and inactivating enzymes interactions with different food components inert ingredients or formulation the first pass effect
factors influencing distribution
barriers blood flow and perfusion rate binding to plasma proteins and tissue volume distribution redistribution
perfusion rate
fat has lowest
kidney has highest
plasma protein binding
only the free drug with diffuse through capillaries
volume distribution
the volume of the drug needed to be distributed to produce the observed blood conc
Vd equation
total amount of drug in body/ drug blood conc
low vd
high binding of drug
high vd
drug bound to tissues
drug redistribution
when distribution of a drug changes with time
