Elimination and Clearance Flashcards
What does IV absorption: -distribution, -elimination graph look like?
What does the IV absorption: + dist, - elimination graph look like?
What does the IV absorption: + dist, + elimination graph look like?
What is clearance?
volume of plasma that is cleared of drug per unit time (Vol/TIME)
What is the equation for clearance?
CL total= CL renal + CL hepatic
renal clearance: urine (most drugs)
hepatic cleanrace: bile (some drugs)
What does kidney disease and old age due to GFR
decrease GFR–> decrease renal clearance=increased half-life
What does the the graph for rate of drug elimination vs plasma drug concentratoin look like?
How do we determine rate of elimination?
clearance is the proportionality factor used to determine rate of elimination
rate of elim (mass/time)= Cl (vol/time) * concentration (mass/vol)
What is the rate of elimination?
Amount (mass of drug) cleared per unit time
What does the graph look like for first order elimination?
Downward sloping line on semi-log plot
-Rate of elimination is proportional to the [Cplama]
What is the equation for half life?
t1/2=tC0-t0.5C0
t1/2= 0.693 * Vd/CL
what happens to hald life if clerance decreases?
clearance goes up
What happens to clerance and half life is Vd is small?
clearance goes up
half life goes down
