Renal Excretion of Drugs Flashcards
elimination
the irreversible removal of drug from the plasma resulting in a decrease in concentration
metabolism
drug is chemically transformed into metabolites
excretion
drug is eliminated without chemical change (as parent compound)
what does renal elimination depend on
glomerular filtration
tubular secretion
tubular reabsorption
total renal elimination is equal to…
rate of filtration + secretion - reabsorption
is glomerular filtration active or passive
passive
direction of glomerular filtration
blood –> filtrate
what does glomerular filtration depend on
size (small <5,00 daltons)
protein binding (unbound only)
is tubular secretion active or passive
active w/ carrier proteins
what direction is tubular secretion
blood –> filtrate
what does tubular secretion depend on
ionization (ionized only)
is tubular reabsorption active or passive
passive
what direction is tubular reabsorption
filtrate –> blood
what does tubular reabsorption depend on
concentration gradient
lipophilicity (lipophilic)
ionization (unionized)
urine flow (slow)
urine pH (promote unionized)
- acidic urine for weak acid drugs
- alkaline urine for weak base drugs
renal clearance
the rate at which plasma is cleared of the drug by the kidneys
