drug clearance: excretion Flashcards
what is the glomerular filtration rate
120 ml/min
type of renal excretion where the rate of elimination = output
glomerular filtration rate
type of renal excretion where the rate of elimination < output
tubular secretion
type of renal excretion where the rate of elimination > output
tubular reabsorption
glucose exhibits what type of renal excretion
tubular reabsorption
what is added to IV solutions for urinary alkalinization
sodium bicarbonate
weak acids can have enhanced excretion with urinary _____
alkalinization
a weak acid is ___ (HA or A-) in alkaline urine
A-
why is elimination enhanced if the urine is alkaline with a weak acid
it is charged so not easily absorbed
what is added to IV solutions for urinary acidification
ammonium chloride
weak bases can have enhanced excretion with urinary _____
acidification
a weak base is ___ (B or BH+) in acidic urine
BH+
graph of first order kinetics
linear
graph of zero order kinetics
nonlinear (exponential)
the rate of elimination for zero order kinetics is ____
saturable and not directly proportional to drug concentration
alcohol exhibits zero order kinetics. does the rate of fall vary with dose?
no. same rate despite diff concentration
intermediate kinetics means that at a low dose, we see ____ order kinetics, but at high doses, we see ___ order kinetics
at low doses: first order (linear)
at high doses: zero order (non-linear)
does the drug concentration reach Css in zero order kinetics?
no
does the drug concentration reach Css in first order kinetics?
yes
is the Css proportional to dose in first order
yes
bioavailability calculation
amount in systemic/ total at start
hepatic extraction ratio
amount lost after liver/total absorbed
calculation for half life
0.693 x Vd / Clearance
how many half lives does it take for a drug to be eliminated from the body
5
