Pharmacokinetics 3

Question 1

weak acid drug: exists in what form in acidic or alkaline environments

Answer 1

more acidic: AH form aka lipid soluble. alkaline: A- aka charged aka less lipid soluble form.

Question 2

placental transfer of drugs: what method? what type of drugs?

Answer 2

simple diffusion. lipid soluble, non ionized drugs more likely to cross.

Question 3

fetal pH vs mother? promotes what transfer?

Answer 3

fetal pH is lower than mother. promotes transfer of basic local anesthetics.

Question 4

only unbound free drug available for (4)?

Answer 4

diffusion across membranes. binding to receptors/enzymes. hepatic metabolism and renal filtration. drugs may compete for binding sites.

Question 5

biotransformation: aka? two phases?

Answer 5

metabolism. phase I = drug made more polar by CYP. phase II = drug conjugation to endogenous compounds from liver.

Question 6

most drug metabolism occurs where? also occurs where? creates what?

Answer 6

liver. also in kidneys, gut, lungs, plasma ad placenta. creates polar products for renal elimination

Question 7

renal excretion of drugs/metabolites: what happens

Answer 7

kidney filters molecules with MW

Question 8

kidney: three main functions

Answer 8

glomerular filtration, secretion, absoprtion

Question 9

rates of renal excretion of drugs affected by

Answer 9

kidney disease, renal blood flow, MW/size, urinary pH, protein binding

Question 10

gallbladder: name of circulation? what happens to drugs

Answer 10

enterohepatic circulation. drug may get secreted into bile, some reabsorption from bile in gut