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Flashcards in Test 2 Deck (64)
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1
Q

Cmax correlates with:

A

both rate and extent of absorption

2
Q

bioavailability depends on

A

both rate and extent

3
Q

cpmax is decreased by

A

a decrease in rate of absorption

4
Q

If the absorption rate for formulation A was SLOWER than formulation B and relative rate of absorption for A was the same as B then:

A

cman for A would be less than B

5
Q

if the extent of absorption was LESS for product A than B and relative rate of absorption for A was the same as B then:

A

cmax for B would be higher than A

6
Q

Drug A and B bind to the same albumin molecule: A is already being given to pt. what is correct concerning giving drug B

A

at the same concentrations the drug with the higher Ka will have the lowest Fu

7
Q

two drugs compete for the same binding site on a protein. what condition would yield higher binding for A than B?

A

higher [A]

8
Q

when a drug undergoes hepatic metabolism, the kinetics appear first order when

A

[drug] are lower than the value of the Km

9
Q

the effect of Vmax on the rate of drug metabolism when a single bolus dose is given would show:

A

the observed half life for metabolism would be smaller for larger Vmax values

10
Q

What is the characteristic of simple competitive inhibition

A

having the same Vmax, but a larger Km when the inhibitor is present

11
Q

What 2 things are expected if plotting Cmax(axis) vs % dissolved at 30 minutes

A

1) as the % dissolved decreased, the max value would decrease
2) as the % dissolved increased, the max value would increase

12
Q

smoking is considered an environmental enzyme inducer for some drugs. if pt stops smoking after being stabilized on a drug, you expect

A

drug levels of drug to increase

13
Q

the classic full crossover bioavailability testing corrects for

A

the differences between people

14
Q

a repeated, full crossover design corrects for

A

BOTH the variability within the same subject and between different subjects

15
Q

if the full crossover design is not repeated, it does not correct for

A

variability within the same subject

16
Q

absolute bioavailability is obtained by comparing results from a particular drug product or dosage for and comparing it to

A

data from an IV bolus dose

17
Q

bioavailability of a drug deals with

A

rate and extent of absorption

18
Q

relative bioavailability compares

A

a new product or formulation to an existing formulation

19
Q

absolute availability could

A

be qual to zero

20
Q

can absolute bioavailability be equal to zero?

A

yes

21
Q

absolute bioavailability cannot

A

be greater than 1

22
Q

absolute availability (F)=1 when

A

ALL of drug is absorbed

23
Q

Tmax is

A

the time of peak plasma concentration

24
Q

AUC measures

A

the extent of drug bioavailability

25
Q

AUC is the area under the drug plasma levels time curve

A

and is equal to the amount of unchanged drug reaching the general circulation divided by the drug clearance

26
Q

Units for AUC are

A

concentration time

27
Q

AUC is not proportional if one of the pathways for elimination becomes saturated, which causes

A

prolonged half life

28
Q

Tmax is the best indicator of

A

the relative rate of drug absorption

29
Q

if the absorption rate for A was faster than B, but the extent of absorption was the same for A and B then tmax

A

for A would be less than B

30
Q

if bioavailability is less than 1, and the AUC obtained by a direct intraportal inject is the same as when you gave the same dose of drug orally:

A

the drug was subject to first pass metabolism

31
Q

An IV bolus dose and a capsule are given. Rate of urinary excretion is measured and plotted. this data:

A

can be used to estimate bioavailability of the capsule formulation

32
Q

in correlating cpm values in vivo with the % dissolved in vitro at time=20 minutes, we expect, if a correlation exists that

A

cpmax will be smaller if the dissolution rate is slower

33
Q

The boys whitney eqn predicts

A

if the particle size is smaller the dissolution rate will potentially be faster

34
Q

the absorption of a very lipid soluble, unionized drug molecule, will most like be eliminated by rate of

A

dissolution

35
Q

to pass the dissolution test in stage 1 (first 6 units)

A

no result is less than Q + 5%

36
Q

the absorption of a very lipid soluble, unionized but somewhat water soluble drug will be limited by rate of

A

perfusion

37
Q

dissolution rate of a weak acid

A

may be slower at a lower pH

38
Q

a drug that would be limited by diffusion rate rather than perfusion rate is most likely

A

a polar water soluble drug of a large size

39
Q

usually disintegration is

A

not rate limiting, but may be if intended

40
Q

clearance of a drug:

A

is constant for a physiologically stable person who eliminates the drug as a first order process

41
Q

clearance can be calculated by

A

extraction ration * blood flow

42
Q

compare drug elimination and clearance

A

elimination rate changes over time while clearance is constant

43
Q

renal cleraance eqn

A

GFR + active secretion - reabsorption

44
Q

oxidation, reduction and hydrolysis rxns are

A

phase I reactions

45
Q

the most frequently found conjugation reaction involves

A

glucuronic acid

46
Q

for a drug known to exhibit non linear pharmacokinetics, as dose increases:

A

the steady state concentration increases more than predicted amount of dose increase

47
Q

passive tubular reabsorption would be lowest for

A

a weak base at pH 2

48
Q

passive tubular reabsorption would be highest for

A

a weak acid at pH 3

49
Q

passive reabsorption of a drug:

A

reduces renal clearance

50
Q

ionization of a weak base

A

decreases its lipid solubility

51
Q

active secretion of a drug by the renal system:

A

increases renal clearance

52
Q

facilitated diffusion occurs

A

only in the presence of a carrier

53
Q

a carrier mediated process for a drug absorption

A

will saturated carrier at drug concentrations approximately twice the value of Km

54
Q

passive diffusion

A

rate increases in direct proportion to drug concentration

55
Q

all drugs are subject to some biliary clearance,

A

is subject to enhancement by active secretion into the bile

56
Q

A scatchard plot is used to determine

A

Ka and n

57
Q

the r in the protein binding equation what does it stand

A

equals ratio of moles of drug bound per total mole of protein

58
Q

the n in protein binding eqn refers to

A

the number of sites for a particular drug per protein molecule

59
Q

the apparent Vd will be very large when

A

the drug is more bound to tissues than plasma proteins

60
Q

IV administration is assumed

A

to be 100% bioavailable

61
Q

IM injections can be used

A

for oil based or insoluble components

62
Q

rectal admin provides:

A

good absorption from solutions retained long enough

63
Q

buccal route is preferred to oral when

A

drug is subject to high first pass metabolism

64
Q

a suspension drug form may be necessary for

A

aqueously insoluble or unstable drugs