ILA: Drug Absorption and Distribution

Question 1

the area b/t minimal effective concentration (MEC) and minimal toxic concentration (MTC)

Answer 1

therapeutic window

Question 2

what kind of administration of drug immediately gets to the max effective dose

Answer 2

IV adminitration

Question 3

drug concentration in plasma

Answer 3

Cp

Question 4

achieve efficacy w/out toxicity is what

Answer 4

first goal of drug therapy

Question 5

get Cp w/in therapeutic window in the shortest possible time is what

Answer 5

second goal of drug therapy

Question 6

maintain Cp w/in therapeutic window during pharmacotherapy

Answer 6

third goal of drug therapy

Question 7

what the body does to the drug is called

Answer 7

pharmacokinetics

Question 8

what the drug does to the body is called

Answer 8

pharmacodynamics

Question 9

plasma concentration correlates with drug concentration at the receptor (increase Cp= increase effect)

Answer 9

central dogma of pharmacokinetics

Question 10

these 4 things affect plasma concentration of drug

Answer 10

ADME (absorption, distribution, metabolism, and elimination)

Question 11

2 main types of drug delivery we will discuss

Answer 11

Oral (P.O. swallowing)
Parenteral (I.V.)

Question 12

size of drug molecule, hydrophobicity, charge, pH trapping, and area of absorption are all what

Answer 12

obstacles to drug absorption

Question 13

what junction prevents paracellular transport

Answer 13

tight junctions

Question 14

flux=

Answer 14

(concentration difference x area)/thickness

Question 15

a _____ drug is a neutral molecule that can reversibly dissociate into anion and proton (H+)

Answer 15

weak acid

Question 16

a ______ drug forms a cation by combining with a proton (H+)

Answer 16

weak base

Question 17

protonated form of a weak acid is ______

Answer 17

neutral (lipid soluble)

Question 18

unprotonated form of a weak base is ______

Answer 18

neutral (lipid soluble)

Question 19

in acidic environment (high proton), a weak acid will exist as what

Answer 19

neutral form (higher uptake)

Question 20

in acidic environment (high proton), a weak base will exist as what

Answer 20

cation form (less uptake)

Question 21

henderson-hasselbach eq. for weak acids

Answer 21

pH= pKa + log [charged/deprotonated/trapped]/[uncharged/protonated/membrane permeable]

Question 22

_____ is the pH at which 50% of molecules dissociate

Answer 22

pKa

Question 23

henderson-hasselbach eq. for weak bases

Answer 23

pH=pKa - log [charged/deprotonated/trapped]/[uncharged/protonated/membrane permeable]

Question 24

when pH of environment (like stomach) is super low, uncharged/permeable form prevails, favoring ________

Answer 24

absorption

Question 25

when pH of environment (like blood) is 7.4, charged form prevails, favoring _____

Answer 25

trapping

Question 26

example of very fast absorption, having therapeutic effect before drug is even metabolized

Answer 26

sublingual administration

Question 27

ex of drug that is administered sublingually

Answer 27

nitroglycerine

Question 28

first pass of absorption when the drug is administered P.O. enteral (into GI tract)

Answer 28

hepatic (portal vein)

Question 29

produce a local effect
prolong systemic action

Answer 29

methods for delayed absorption

Question 30

once absorption happens, what 3 things come next

Answer 30

1. binding to plasma proteins
2. distribution
3. elimination

Question 31

binds mainly acidic drugs

Answer 31

plasma albumin

Question 32

_______ do not saturate the plasma protein binding sites

Answer 32

therapeutic doses

Question 33

drug that binds to fat and cannot achieve rapid induction; it’s a general anesthetic

Answer 33

thiopental

Question 34

drug that binds to calcium and leads to bone and teeth toxicity

Answer 34

tetracycline

Question 35

apparent volume of distribution

Answer 35

Vd

Question 36

volume of distribution (Vd) (in vitro)=

Answer 36

Vd= D/Cb
D- dose
Cb- solvent in beaker

Question 37

volume of distribution (Vd) (in vivo)=

Answer 37

Vd=D/Cp

D-dose
Cp- concentration of drug in plasma

Question 38

where does most of the drug go when it is being distributed

Answer 38

most to tissues, some is eliminated

Question 39

LD50 or TD50/ED50

Answer 39

therapeutic index