Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

SRNA4TopicsAnesthesia > EXAM 2 Reading (N.Ch6) > Flashcards

EXAM 2 Reading (N.Ch6) Flashcards

1
Q

The plasma half-life of a drug is inversely proportional to its

A

Rate of clearance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

When you administer a bolus dose of a drug intravenously, which tissue would have an increase in the tissue concentration of the drug first?

A

Liver

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

The vessel-rich group,

A

which is comprised of the highly-perfused organs such as the brain, heart, liver, kidneys, lungs, and endocrine organs, receives 75% of the cardiac output.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

They exhibit the most rapid equilibration of the drug with the blood (which group) ?.

A

The vessel-rich group

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

After distribution to the vessel-group, The drug then

A

redistributes to other, less-perfused tissues such as muscle, adipose tissue, and bone.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the most prevalent protein in the bloodstream?

A

Albumin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Which of the following plasma proteins binds preferably to acidic drugs?

A

Albumin is capable of binding drugs that are alkaline or neutral, but binds preferably to acidic drugs.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

2 proteins that bind preferably to basic drugs.

A

Alpha-1 acid glycoprotein and Beta-globulin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Proteins that binds to corticosteroids.

A

Transcortin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Approximately what percent of the cardiac output goes to the adipose tissue group?

A

6%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

The vessel-rich group receives ___%of the cardiac output.

A

75%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

The muscle group receives about____% of the cardiac output

A

19%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

The adipose group receives ____% of the cardiac output,

A

6%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Vessel-poor group receives a

A

% negligible proportion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Which of the following agents exemplifies zero-order kinetics?

A

Alcohol (ethanol)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Zero-order kinetics refers to metabolism in which

A

the amount of the drug eliminated over time is constant.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

The clearance of a drug is inversely proportional to

A

its half-life

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

The clearance of a drug is defined as the C.

A

volume of plasma that is cleared of a drug per unit of time and is dependent upon the body’s ability to metabolize and eliminate the drug.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

The formula for clearance is

A

Clearance = Q X E (where Q is blood flow and E is the extraction ratio).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Clearance is _____-(definition) - What does it mean?

A

directly proportional to the dose administered and inversely related to the half-life of the drug. Meaning, as the half-life of the drug increases, the volume that is cleared per unit of time decreases.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

How does hypoalbuminemia affect the action of a highly protein-bound drug like warfarin?

A

Its effect is intensified

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

% of warfarin is protein-bound

A

About 98

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

As the plasma protein level decreases, there is

A

less of the protein available for the drug to bind with, and more of the free form of the drug is available to exert its pharmacologic action.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Hypoalbuminemia and highly protein bound drugs?

A

hypoalbuminemia intensifies the action of highly protein-bound drugs.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Which of the following statements are correct? (select two)

Plasma half life and zero-order kinetic

A

The plasma half-life of a drug is inversely proportional to its rate of clearance
A drug with zero-order kinetics exhibits a constant rate of elimination

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Enzyme induction

A

reduces the plasma half-life of agents that are metabolized by that particular metabolic pathway.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

According to the Fick equation, the most important factor in determining the rate of diffusion of a drug across a membrane is the

A

concentration gradient of the drug.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Membrane thickness is an important factor in the

A

rate of diffusion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Molecular weight, which affects the

A

diffusion coefficient (p)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Which of the following drugs will be more non-ionized than ionized at physiologic pH? (select two)

A

An acid with a pKa of 9.5

A base with a pKa of 4.2

31
Q

For a WEAK ACID explain ph vs pka

A

pH < Pka –> Nonionized

pH > Pka –> Ionized

32
Q

For a WEAK BASE explain ph vs pka

A

pH < Pka –> IOnized

pH > Pka –> NOn-Ionized

33
Q

Which pharmacokinetic model best illustrates how lipid-soluble drugs are distributed?

A

Two-compartment model

34
Q

For many drugs, a single-compartment model, which represents In

A

the distribution of the drug throughout the entire body sufficiently explains the pharmacokinetics of the drug.

35
Q

For lipid-soluble drugs, however, what better illustrates how the drug is distributed?

A

two-compartment model better illustrates how the drug is distributed.

36
Q

The peripheral compartment consists of the

A

muscles, adipose tissue, and bone

37
Q

The two-compartment model, there is a central compartment, which consists of the

A

intravascular fluid and highly perfused tissues such as the heart, lungs, brain, kidneys, and live

38
Q

Two-compartment membrane include the

A

Central and peripheral compartments

39
Q

Immediately after administration of a bolus dose of a particular drug that undergoes first-order kinetics, you measure the plasma concentration, and it is 100 mcg/mL. The drug has an elimination half-life of 5 minutes. What would you expect the plasma concentration to be 15 minutes after the initial administration?

A

The elimination half-life of the drug is five minutes. The passing of 15 minutes would constitute three half-lives. With each half-life, the plasma concentration of the drug should drop by half. So, after the first five minutes, it would be 50 mcg/mL. After the second five minutes, it should be 25 mcg/mL. After the third five minutes, it should be 12.5 mcg/mL.

40
Q

Which form of a drug is responsible for reaching the site of action?

A

Non-Ionized

41
Q

In solution, the non-ionized form of a drug is considered to confer pharmacologic activity, because it is in then

A

non-ionized form that the drug is able to pass through lipid-soluble biologic membranes to reach its point of actio

42
Q

Which term refers to the amount of the drug that is able to reach its target receptor after it is introduced into the circulatory system?

A

Bioavailability

43
Q

A drug is being administered by continuous infusion, and its plasma concentration is now constant. The drug is said to be in

A

a steady state

44
Q

Steady state refers to a .

A

stable plasma concentration of a drug.

45
Q

With a single dose of a drug, the plasma concentration

A

increases as it is absorbed, reaches a peak plasma concentration, and then decreases as it is eliminated.With the chronic administration of a drug or a continuous infusion, however, the supply of the drug is continually renewed

46
Q

Once the rate at which it becomes bioavailable equals the rate at which it is eliminated, the plasma concentration becomes

A

stable, and the drug is said to be at a steady state.

47
Q

Presystemic elimination would be most likely to occur in a drug administered

A

Orally

48
Q

Drugs administered orally may undergo_____What does it mean?

A

presystemic elimination. That is, they may be eliminated before they are able to reach the systemic circulation

49
Q

What is the first-pass hepatic elimination.

A

The stomach acids may hydrolyze the drug, gastric enzymes can deactivate it, or it can be metabolized in the liver as it passes through the portal circulation before it reaches the systemic circulation, a process known as

50
Q

The clearance of a drug is dependent upon (2)

A

blood flow and the Extraction ratio

51
Q

There are also separate concepts of hepatic clearance and renal clearance that become important

A

when one or both organs has an alteration in either blood flow or the extraction ratio.

52
Q

In pharmacokinetics, steady-state refers to a situation in which

A

the concentration of a drug in the tissues does not change from moment-to-moment

53
Q

Steady-state refers to a state in which all of the tissues in the body have

A

had time to reach equilibrium.

54
Q

Which route of administration requires a significantly higher dosage in most drugs to achieve a therapeutic plasma concentration?

A

Oral

55
Q

Because of extensive first-pass metabolism, the oral dose of most drugs must be significantly

A

higher to generate therapeutic plasma concentrations.

56
Q

The administration of lidocaine to a parturient can result in an increased concentration of the drug in the fetus. This concept that describes why this occurs is

A

ion trapping

57
Q

Explain ion trapping?

A

When the lipid-soluble portion of a basic drug like lidocaine crosses the placenta and enters the acidic environment of the fetus, the drug becomes more ionized and unable to cross back through the placenta. As a result, a higher concentration of the drug exists in the fetus than in the mother. This concept is known as ion trapping.

58
Q

The diffusion of a drug across a membrane from an area of higher concentration to an area of lower concentration without the expenditure of energy is

A

Passive Transport

59
Q

Which of the following measurements predicts the time it takes for 50% of a drug to be eliminated from the central compartment when a continuous infusion is discontinued?

A

Context-sensitive half-time

60
Q

The context-sensitive half-time predicts the time it takes for

A

50% of a drug to be eliminated from the central compartment when a continuous infusion is discontinued.

61
Q

The volume of distribution describes the

A

virtual volume into which the drug is distributed.

62
Q

The steady-state plasma concentration corresponds to the

A

steady concentration at the site of action and is determined by a concentration-response curve

63
Q

It should be noted that context sensitive half-times are computer models that only

A

predict the time for 50% of the drug in the central compartment to be eliminated. It does not predict the time for recovery from the drug.

64
Q

Which route of administration will produce a lower bioavailability of most drugs due to rapid metabolism in the liver via the first-pass effect?

A

Oral

65
Q

Approximately how much of a drug will be remaining in the bloodstream after four elimination half-lives have passed for a drug that undergoes first-order kinetics?

A

5%

66
Q

Which drug administration route would have the highest bioavailability?

A

IV

67
Q

The intravenous route, by definition has __% bioavailability, has a

A

100% bioavailability because the entire dose of drug administered is available within the circulatory system immediately.

68
Q

Intramuscular and subcutaneous administration both range between

A

75 and 100% bioavailability.

69
Q

Routes such as oral, topical, and inhalation can vary widely depending on the chemical characteristics of the particular drug and how they affect its ability to be

A

absorbed into the bloodstream.

70
Q

Hepatic enzyme induction will result in a reduction in the ____ of a drug.

A

Half life.

71
Q

If liver enzymes are exposed to particular compounds or drugs over a period of time, they will

A

increase their activity, resulting in an increased ability to metabolize the drugs. This is referred to as hepatic enzyme induction, and it can result in a reduced half-life of a drug

72
Q

The plasma half-life of a drug is directly proportional to its

A

Volume of distribution

73
Q

Which is the single most important enzyme, accounting for 40-45 percent of all mediated drug metabolism?

A

CYP3A4

SRNA4TopicsAnesthesia (47 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions