Lecture 4: Pharmacokinetics

Question 1

pharmacokinetics

Answer 1

how drugs are handled by the body

Question 2

goal of pharmacokinetics

Answer 2

predicting time course of active drug in blood that is available at receptor sites

Question 3

the time course of a drug’s action allows a determine of ___

Answer 3

the intensity of the drug effect as a function of time

Question 4

ADME

Answer 4

absorption
distribution
metabolism
elimination

Question 5

absorption

Answer 5

movement of drug from site of administration to the blood

Question 6

distribution

Answer 6

movement of drug from blood to rest of body

Question 7

metabolism

Answer 7

breakdown of drug

Question 8

elimination

Answer 8

removal of drug’s metabolic waste products from the body

Question 9

therapeutic index (TI)

Answer 9

in animals: ratio of the dose that causes death in 50% of the population (LD50) to dose that is effective in 50% of population
TI = (LD50)/(ED50)

Question 10

therapeutic ratio (TR)

Answer 10

in humans: ratio of dose that causes toxicity in 50% of population (TD50) to dose that is effective in 50% of the population (ED50)
TR = (TD50)/(ED50)

Question 11

Cmax

Answer 11

max concentration of drug

Question 12

Tmax

Answer 12

time at which Cmax is reached

Question 13

T1/2

Answer 13

half life

Question 14

AUC

Answer 14

area under the curve; total exposure to drug

Question 15

half life

Answer 15

time it takes to remove half of current concentration of drug from the body

Question 16

enteral routes

Answer 16

oral, rectal

Question 17

drugs enter the capillaries and blood through ____

Answer 17

passive diffusion down concentration gradients

Question 18

4 disadvantages of oral admin

Answer 18

1. stomach distress
2. hard to know how much will be absorbed
3. stomach acid
4. slow onset

Question 19

path to brain for inhaled drugs

Answer 19

rapid absorption into blood through lungs, pulmonary capillaries carry drug to left side of heart and into arteries

Question 20

benefits of transdermal administration

Answer 20

continuous absorption over hours or days

Question 21

2 types of IM injections

Answer 21

1. rapid onset/short duration (aqueous solution

2. slow onset/prolonged duration (oily solution)

Question 22

2 types of IM injections

Answer 22

1. rapid onset/short duration (aqueous solution

2. slow onset/prolonged duration (oily solution)

Question 23

pulmonary circulation

Answer 23

circulation of blood from heart to lungs for oxygenation and back to heart (artery = from heart, vein = to heart)

Question 24

systemic circulation

Answer 24

between heart and all other body tissues

Question 25

function of right side of heart

Answer 25

veins flow to it; blood flows from it to brain

Question 26

function of left side of heart

Answer 26

oxygenated blood goes from there to rest of body; oxygenated blood goes from there to brain

Question 27

blood returning to the heart from the ____ enters the ___ and flows to the ___ ventricle

Answer 27

1. systemic venous system 2. right atrium 3. right ventricle

Question 28

with contraction of the heart, blood is pumped into the ___, leading to the ___. once in pulmonary capillaries, ___ is lost and replaced with ____

Answer 28

1. pulmonary arteries 2. lungs 3. CO2 is lost and replaced with O2

Question 29

oxygenated blood returns to the heart in the ___ veins, which empty into the ___. with heart contraction, blood is pumped from ____ into ___ and is carried to ___

Answer 29

1. pulmonary 2. left atrium 3. left ventricle 4. aorta 5. body tissues and brain

Question 30

3 places drug molecules can be found in blood

Answer 30

1. plasma (free; water-soluble drugs) 2. attached to proteins like albumin (bound) 3. platelets (lipid soluble drugs)

Question 31

4 membranes that affect drug distribution

Answer 31

1. cell membranes 2. capillary walls 3. BBB 4. placental barrier

Question 32

cell membranes are made of a ____ and therefore only permeable to ___

Answer 32

1. phospholipid bilayer | 2. small lipid-soluble molecules

Question 33

experimental methods allow small therapeutic agents to pass thru BBB by turning off ___

Answer 33

P-glycoprotein

Question 34

drugs cross placenta by ___

Answer 34

passive diffusion

Question 35

5 compartments

Answer 35

1. blood 2. fat 3. extracellular fluid 4. intracellular fluid 5. other

Question 36

when drugs move into a new compartment...

Answer 36

some of that drug is sequestered by binding to proteins within that compartment

Question 37

Kc

Answer 37

equilibrium constant; number showing whether balance is in forward or backward direction

Question 38

Kc is dep on (3)

Answer 38

1. permeability of barriers 2. pH of compartments 3. binding capacity

Question 39

Vd

Answer 39

volume of distribution: total amt of drug in the body/conc of drug in plasma

Question 40

synonym for metabolism

Answer 40

biotransformation

Question 41

____ drugs are hard for kidneys to hold on to, so they ___ before excretion

Answer 41

1. lipid soluble | 2. cross back into circulation

Question 42

the kidneys change molecules from ____ to ____

Answer 42

highly lipid soluble | less lipid soluble; can also change to another lipid soluble molecule, active metabolite

Question 43

main category of enzymes

Answer 43

cytochrome P450

Question 44

location of enzymes

Answer 44

hepatocytes (liver cells)

Question 45

two enzymes that metabolize over 50% of drugs

Answer 45

CYP2D6 | CYP3A

Question 46

two enzymes that metabolize over 50% of drugs

Answer 46

CYP2D6 | CYP3A4

Question 47

4 potential results of metabolism

Answer 47

1. active drug to inactive metabolite 2. active drug to active metabolite 3. inactive prodrug to active metabolite 4. active drug to toxic metabolite

Question 48

grapefruit juice inhibits ___

Answer 48

CYP3A4

Question 49

enzyme induction

Answer 49

liver "learns" and creates more enzymes for a specific drug

Question 50

graphs for 0, first, and second order kinetics

Answer 50

page 53

Question 51

plasma concentration is plotted as ___

Answer 51

log concentration

Question 52

what kind of function describes terminal decay?

Answer 52

exponential decay

Question 53

a quantity is subject to exponential decay if it decreases at a rate proportional to its...

Answer 53

current value

Question 54

in how many half lives is elimination achieved?

Answer 54

6

Question 55

4 routes through which drugs can leave the body

Answer 55

1. kidneys 2. lungs 3. bile 4. skin

Question 56

diagram of kidney

Answer 56

page 61

Question 57

three types of tolerance

Answer 57

1. metabolic 2. cellular-adaptive or pharmacodynamic response 3. behavioral conditioning (conditional stimuli elicit compensatory conditional response)