Therapeutic Drug Monitoring

Question 1

MEC

Answer 1

minimum effective concentration

Question 2

MTC

Answer 2

minimum toxic concentration

Question 3

Trough

Answer 3

lowest drug level

draw sample prior to next dose given

Question 4

peak

Answer 4

highest drug level, draws at peak of absorption for particular drugs

Question 5

steady state

Answer 5

drug intake & outtake equal so drug level stays in therapeutic range

Question 6

bioavailability

Answer 6

unchanged drug entering the bloodstream

Question 7

of doses to get to therapeutic range usually

Answer 7

at least 5 doses

Question 8

Drug distribution

Answer 8

administration
absorption
distribution
excretion

Question 9

methods that lead to GI absorption

Answer 9

oral, rectal or sublingual routes of administration

Question 10

GI absorption

Answer 10

drugs go through the liver & go through ‘first pass’
drug must go through unionized (hydrophobic), absorb passive diffusion
portion of unchanged drug entering the blood is bioavailable

Question 11

injected drugs absorption

Answer 11

enter the blood stream via IV, intramuscular, intradermal, subcutaneous, respiratory, or percutaneous
do not have to deal with liver’s first pass effect

Question 12

factors that change drug absorption in GI

Answer 12

GI motility
pH
inflamed

Question 13

carrier proteins of drugs

Answer 13

albumin & alpha-1-acid glycoprotein (!!!)

Question 14

free drug levels affected by:

Answer 14

protein binding
disease state
kidney function
additional drugs being present
hepatic disease
acid-base disturbance
nephrotic syndrome

Question 15

lipid soluble drug distribution

Answer 15

travel through cell membranes & partition in lipid compartments in cells

Question 16

polar drug distribution

Answer 16

travel to water part of cell & stay there

Question 17

ionized drug distribution

Answer 17

diffuse slowly out of blood & into cells

get filtered in kidneys or taken out by liver

Question 18

major organ for drug metabolism

Answer 18

liver via mixed function oxidase system or MFO
converts hydrophobic drug into water soluble substances
go out bile or into blood & out the kidney

Question 19

secondary sites for drug metabolism

Answer 19

lungs
kidneys
skin
brain
GI

Question 20

drug metabolite activity levels

Answer 20

bound drug & active metabolite

Question 21

metabolism of lipid soluble drugs

Answer 21

non-polar to soluble form using renal excretion via hydroxylation, deamination, sulfoxidation, dealkylation
enzymes: Monooxygenases or mixed function enzymes (MFO) in liver

Question 22

MFO phase I

Answer 22

produce reactive intermediates from drug

can accumulate & may not be able to go into phase iI

Question 23

MFO phase II

Answer 23

conjugates reactive intermediate to water-soluble products

intermediates are conjugated to glutathione, glycine, phophate or sulfate

Question 24

MFO system influenced

Answer 24

process is inducible
drug-drug interactions are competing for MFO system
changes in hepatic health will affect MFO

Question 25

renal clearance

Answer 25

parent drug & metabolite are subject to glomerular filtration
if renal function is compromised, then longer half-life

Question 26

acid urine

Answer 26

leads to more alkaline drug excretion & vice versa

Question 27

samples

Answer 27

usually serum/plasma

urine samples are used when wanting to look at parent drug & metabolites

Question 28

cardiac drugs

Answer 28

digoxin/ digitoxin
quinidine
procainamide
disopypramide/norpace

Question 29

digoxin/digitoxin

Answer 29

used for CHF
very toxic - tissue levels are 15-30x the serum/plasma level
stays in lipid portion of tissues
stops Na/K ATPase pumps to prevent fluid build up in cells & encourage K to be excreted in the urine

Question 30

quinidine

Answer 30

DO NOT MIX W/ DIGOXIN

cardiac drug

Question 31

procainamide

Answer 31

active metabolite - NAPA

cardiac drug

Question 32

disopypramide/norpace

Answer 32

used as quinidine substitute drug

cardiac drug

Question 33

anti-epileptic drugs

Answer 33

all are GI absorbed, liver metabolized & renal excreted

Question 34

older AEDs

Answer 34

highly bound to protein; all toxic 
phenobarbital 
phenytoin/dilantin
valproic acid 
primidone
carbamazepine

Question 35

2nd gen AEDs

Answer 35

felbamate
gabapentin
lamotrigine
tiagabine
topiramate

Question 36

aminoglycosides

Answer 36

anti-microbials: gentamycin, kanamycin, tobramycin, neomycin
give by IV
bind to ribosomes & inhibit protein synthesis

Question 37

anti-microbial side effects

Answer 37

affect hearing, balance
anemia, cytopenias
red man syndrome 
nephrotoxic
ototoxic

Question 38

vancomycin

Answer 38

affects cell walls of bacteria

G +

Question 39

Tricyclic antidepressants (TCAs)

Answer 39

takes 2-4 weeks to see effects; drug metabolized by liver

imipramine, amitriptyline, dozepin

Question 40

Tricyclic antidepressants (TCAs)

Answer 40

takes 2-4 weeks to see effects; drug metabolized by liver

imipramine, amitriptyline, dozepin

Question 41

Clozepine

Answer 41

used for schizophrenia

Question 42

Olanzapine

Answer 42

used for schizophrenia
lose 40% to first pass through liver
given IV

Question 43

immunosuppressive drug specimens

Answer 43

all collected in EDTA due to drug affiliation w/ RBCs

Question 44

immunosuppressive drugs

Answer 44

cyclosporine
tacrolimus
sirolimus
mycophenolic acid
all are eliminated through liver