Dose Optimization I Exam 1

Front 1

True/False
The value of Vt is the same for all drugs (38 L)
Assume passive diffusion as the driving form for distribution.

Back 1

False. can be either 15 or 38 L

Front 2

True/False
The value of Vp is the same for all drugs (3L)
Assume passive diffusion as the driving form for distribution.

Back 2

True

Front 3

True/False
For a drug that binds to a high affinity-low capacity binding protein in plasma, the fu and the volume of distribution might depend on the dose of the drug.
Assume passive diffusion as the driving form for distribution.

Back 3

True

Front 4

True/False
Assume two drugs (identical molecular weight, same dose given): one neutral drug (Drug A) and one acidic drug (pka=7.4, Drug B). Drug A and the unionized form of drug B have the same partition coefficient. The fraction unbound in plasma and tissue is 0.5 for both drugs. Drug B will enter tissues somewhat slower than drug A
Assume passive diffusion as the driving form for distribution.

Back 4

True
At pKa of 7.4, 50% of drug B is unionized, while the neutral drug A is 100% unionized

Front 5

True/False
A weak acid, whose unionized form shows a high partition coefficient is likely to cross most membrane barriers.
Assume passive diffusion as the driving form for distribution.

Back 5

True
At pH 7.4, a weak acid is significantly unionized.
High partition coefficient = Lipophilic

Front 6

True/False
A volume of distribution of 41 L for a lipophilic drug, suggest that the drug will not bind to tissue and plasma proteins.
Assume passive diffusion as the driving form for distribution.

Back 6

False.
In the equation Vd = Vp+Vt(fu/fut), if fu = fut (any number) then this statement is false.

Front 7

True/False
What could be possible reasons for babies having often a smaller volume of distribution (expressed in L) for lipohilic drugs than adults. Assume for this question that plasma protein binding is the same in babies and adults.
The term Vt is smaller in babies than in adult

Back 7

True

Front 8

True/False
What could be possible reasons for babies having often a smaller volume of distribution (expressed in L) for lipohilic drugs than adults. Assume for this question that plasma protein binding is the same in babies and adults.
The term Vp is smaller in babies than in adult

Back 8

True

Front 9

True/False
What could be possible reasons for babies having often a smaller volume of distribution (expressed in L) for lipohilic drugs than adults. Assume for this question that plasma protein binding is the same in babies and adults.
Transporters pumping the drug into the tissues are more active in babies.

Back 9

False. Transporters pumping the drug into the tissues decreases fut and therefore increases Vd.

Front 10

True/False
What could be possible reasons for babies having often a smaller volume of distribution (expressed in L) for lipohilic drugs than adults. Assume for this question that plasma protein binding is the same in babies and adults. What statements might explain this finding.
Assuming that adults have more fat tissue, this fact could explain it.

Back 10

True

Front 11

True/False
Compared to skin, liver would have a higher rate of uptake for small lipophilic drugs due to its higher blood flow rate.
Assume no active transport.

Back 11

True

Front 12

True/False
The rate with which hydrophilic compounds will move across well-built membranes will depend on the plasma protein binding of this drug.
Assume no active transport.

Back 12

True
Plasma protein binding affects concentration gradient in Fick's Law

Front 13

True/False
Perfusion limited distribution is a type of drug distribution into tissue that
occurs for drugs and tissues with high permeability.
Assume no active transport.

Back 13

True

Front 14

A 25 yr old, 70 kg male patient with gram-negative pneumonia, was being treated with gentamicin. Gentamicin had been given as an iv bolus (2 mg/kg). Two samples were taken after dosing, and data is shown as following:
Time (h) 4
Concentration (mg/L) 5.0

Time (h) 10
Concentration (mg/L) 1.0

Calculate the AUC0-∞. (Assume first-order elimination for gentamicin)
A: 31mg/L*hr
B: 61 mg/L*hr
C: 20 mg/L*hr
D: 9.0 mg/L*hr
E: none of the above

Back 14

B: 61 mg/L*hr

Front 15

A 25 yr old, 70 kg male patient with gram-negative pneumonia, was being treated with gentamicin. Gentamicin had been given as an iv bolus (2 mg/kg). Two samples were taken after dosing, and data is shown as following:
Time (h) 4
Concentration (mg/L) 5.0

Time (h) 10
Concentration (mg/L) 1.0

Calculate the half-life of this drug
(Assume first-order elimination for gentamicin)
A: 2.6 hr
B: 3.0 hr
C: 2.1 hr
D: 9.0 hr
E: none of the above

Back 15

A: 2.6 hr

Front 16

A 100 mg dose of a drug was administered to patient 1 by IV bolus injection. A 200 mg dose of the same drug was administered to patient 2 by IV bolus injection. For patients A and B, the initial concentrations were 1.25mg/L and 2.5mg/L, respectively. This drug follows a one-compartment body model, crosses membranes easily, distributes well into all tissues, and is around 50% bound to plasma proteins. Why is the initial plasma concentration different for these two patients?
A Patient B has more fat tissue than Patient A.
B: Plasma unbound fraction in Patient B is higher than that in Patient A.
C: Tissue unbound fraction in Patient B is higher than that in Patient A.
D: Patient B has larger volume of distribution than Patient A.
E: None of Above

Back 16

E: None of Above

Front 17

If we know that the plasma drug concentration just after a gentamycin dose was given is 12.8 mg/L and the half live is 3.46 hours, what is the concentration after 9 hours. Assume that the result will be between 1.0 and 9.9.mg/L.

Back 17

2.1 mg/L

Front 18

True/False
A water-soluble drug will pass across muscle membranes faster than across brain membranes (assume permeability-rate limitations).

Back 18

True

Front 19

True/False
A neutral, lipophilic drug is likely to be absorbed faster in the intestines than in the stomach. Remember that stomach and intestine differ in their properties.

Back 19

True

Front 20

True/False
Lipophilic drugs are generally taken up fast by highly perfused organs.

Back 20

True

Front 21

True/False
Ionized and lipophilic drugs are most likely to cross most membrane barriers.

Back 21

False. Unionized

Front 22

True/False
Drugs with a high tissue binding always have a large volume of distribution.

Back 22

False. do not always depending on plasma binding

Front 23

J. Mary was admitted into hospital due to drug intoxication. Her body weight is 60kg. Drug U5127 was used to control the symptoms. U5127 is administered via IV bolus at a dose of 0.25 mg/kg. After drug exposure, they found that U5127 concentration-time profile can be best described by one-compartmental linear model with the equation, { (Unit: mg/L)}, where C represents U5127 concentration at time t (hr). Calculate U5127 volume of distribution. teC⋅−⋅=116.033.0
A: 45 L
B: 0.76 L
C: 38 L
D: 18 L
E: none of the above

Back 23

A: 45 L
Dose = 60*0.25 = 15 mg
C = 0.33*e^(-0.116*t), and equation for one-compartment model is C=C0*e^(-Ke*t) then
Co=0.33 mg/L
Vd = Dose/C0
Vd = 15/0.33 = 45 L

Front 24

Quinidine is bound to both of plasma albumin and alpha-1-acid glycoprotein. In patients with chronic liver disease plasma protein binding is decreased by 20%. How will the volume of distribution change in patients? (Assume the fraction unbound in tissue is 70% in both patients and normal subjects, and the fraction bound in plasma is 80% in normal subjects.)
A: Increase to 37.74 L
B: Increase to 22.54 L
C: Stay the same as 13.86 L
D: Stay the same as 46.43 L
E: Decrease to 11.69 L

Back 24

B: Increase to 22.54 L
80% of plasma protein binding is used for calculation of normal people
Vd= Vp + Vt * Fu/Fu,t
Vd= 3 + 38* 0.2/0.7 = 13.86 L (normal patient)
Vd= 3 + 38* 0.36/0.7 = 22.54 L (in patients with chronic liver disease)

Front 25

True/False
Compared to skin, liver would have a higher rate of uptake of perfusion-limited lipophilic drugs due to its higher blood flow rate.

Back 25

True

Front 26

True/False
Distribution to a specific tissue for permeability-limited hydrophilic drugs depends on how much and how quickly the blood gets to the specific tissue.

Back 26

False. perfusion-limited

Front 27

True/False
Perfusion limited distribution is a type of drug distribution into tissue that occurs when the drug is able to cross membranes easily.

Back 27

True

Front 28

A 25 yr old, 70 kg male patient with gram-negative pneumonia, was being treated with gentamicin. Gentamicin had been given as an iv bolus (2 mg/kg). Two samples were taken after dose, and data is shown as following:
Time (h) 4
Concentration (mg/L) 2.5

Time (h) 10
Concentration (mg/L) 0.5

Calculate the AUC0-∞. (Assume first-order elimination for gentamicin, and please use trapezoidal rule to calculate.)
A: 30.5 mg/L*hr
B: 34.1 mg/L*hr
C: 19.6 mg/L*hr
D: 9.0 mg/L*hr
E: none of the above

Back 28

A: 30.5 mg/L*hr

First, need to find out the drug concentration at time zero (C0),
ke = ln(C2/C1) / (t1-t2) = ln (0.5 / 2.5) / (4-10) = 0.268 h^-1
Ct = Co*e^(-ke*t)
Co = Ct*e^(-ke*t) = 2.5 *e^(0.268*4) = 7.303 mg/L

Then, using trapezoidal rule:
AUC(t1-t2) = (C1+C2)/2 * (t2-t1)
Sum = 28.606

AUC10-∞ = Cx/ke = 0.5/0.268 = 1.866 mg*h/L

AUC0-∞ = AUC0-10 + AUC10-∞ = 28.606 + 1.866 = 30.5 mg*h/L.

Front 29

A 100 mg dose of a drug was administered to two patients by IV bolus injection. For patients A and B, the initial concentrations (C0) were 1.25mg/L and 2.5mg/L, respectively. This drug follows a one-compartment body model, crosses membranes easily, distributes well into all tissues, and is around 50% bound to plasma proteins. Why is the initial plasma concentration different for these two patients? Select the correct answer from below.
A: Patient B has more fat tissue than Patient A.
B: Plasma unbound fraction in Patient B is higher than that in Patient A.
C: Tissue unbound fraction in Patient B is higher than that in Patient A.
D: Patient B has larger volume of distribution than Patient A.
E: None of Above

Back 29

C: Tissue unbound fraction in Patient B is higher than that in Patient A.

For a dose administered IV bolus, Cp(0)=D/Vd

Since both patients received the same dose and achieved different initial concentrations, Vd must be different for these two patients. Vd may be calculated by rearranging the equation above to give)
Vd=D/Cp(0)
For patient A, Vd=100 mg/1.25 mg/L = 80 L
For patient B, Vd =100/2.5 mg/L = 40 L
For a drug that distributes well into all tissues and crosses membranes easily, the tissue volume into which a drug may distribute is 38 L (total tissue water). Plasma volume is 3 L. The volume of distribution may be related to these plasma and tissue volumes by Vd = Vp + Vt* fu/fut
fu is given as 0.5. If we assume a tissue water volume of 38L for both patients, fuT must be different in these patients. The expression above may be rearranged to give.
fut = Vt * fu/(Vd-Vp)
For patient A, = 0.25
For patient B, = 0.51
Thus, the difference in Vd 's may be explained by the 2-fold difference in tissue binding of the drug. (An alternative hypothesis is that patient A has more fat tissue leading to more binding of the drug. If more drug is bound, the free fraction decreases.)
9

Front 30

Given a lipophilic drug that can enter all tissues easily , state how the volume of distribution will change under the following condition. If not mentioned, other parameters are assumed to be fixed.
Both fu and fu, T double
A: Increase;
B: Decrease
C: No change
D: Not enough information given to answer question

Back 30

C: No change

Front 31

True/False
A drug that does not bind to plasma proteins and tissue components has a Vd of 41 L
The drug is likely to be hydrophilic

Back 31

False. lipophilic

Front 32

True/False
A drug that does not bind to plasma proteins and tissue components has a Vd of 41 L
VT is likely to be round 18 L

Back 32

False. 38 L

Front 33

True/False
A drug that does not bind to plasma proteins and tissue components has a Vd of 41 L
At equilibrium, the free drug concentrations in plasma and tissue will be identical.

Back 33

True

Front 34

True/False
A drug that does not bind to plasma proteins and tissue components has a Vd of 41 L
At equilibrium, the total blood concentrations in plasma and tissue will be identical.

Back 34

False?

Front 35

Imagine a drug that is given as an intravenous bolus. The dose was 80 mg. The elimination follows first order principles. 2 hours after administration the drug a concentration C1 of 1.48 μg/ml is observed. Four hours after the administration the concentration C2 was 0.74 μg/ml
What is the elimination rate constant of this drug?
A) 0.346 h-1
B) 0.693 h
C) 0.693 h-1
D) 0.346 μg/(ml*h)
E) 0.370 h-1

Back 35

A) 0.346 h-1

Front 36

Imagine a drug that is given as an intravenous bolus. The dose was 80 mg. The elimination follows first order principles. 2 hours after administration the drug a concentration C1 of 1.48 μg/ml is observed. Four hours after the administration the concentration C2 was 0.74 μg/ml
What will the concentration be 8 hours after injection? (10 points)
A) 0.370 μg/ml
B) 0.370 mg/ml
C) 0 μg/ml
D) 0.185 μg/ml
E) none of the above

Back 36

D) 0.185 μg/ml

Front 37

Imagine a drug that is given as an intravenous bolus. The dose was 80 mg. The elimination follows first order principles. 2 hours after administration the drug a concentration C1 of 1.48 μg/ml is observed. Four hours after the administration the concentration C2 was 0.74 μg/ml
What is the concentration best describing the concentration directly after injection of the drug. (10 points)
A) 2 μg/ml
B) 3 μg/ml
C) 4 μg/ml
D) 5 μg/ml
E) none of the above

Back 37

B) 3 μg/ml

Front 38

Imagine a drug that is given as an intravenous bolus. The dose was 80 mg. The elimination follows first order principles. 2 hours after administration the drug a concentration C1 of 1.48 μg/ml is observed. Four hours after the administration the concentration C2 was 0.74 μg/ml
What is the half-life of this drug? (10 points)
A) 1.0 h
B) 1.3 h
C) 3.0 h
D) 4.0 h
E) none of the above

Back 38

E) none of the above

Front 39

A patient with renal dysfunction received a dose of vancomycin (first order elimination). Plasma concentrations were 22 and 15 mg/L at 24 and 48 hours after drug administration. Plot these two plasma concentrations on semilog paper and determine how many hours after drug administration the concentration would reach 10 mg/L (10 points)
A. 2 days
B. 3 days
C. 4 days
D. 5 days
E. None of the above

Back 39

B. 3 days

Front 40

A patient with renal dysfunction received a dose of vancomycin (first order elimination). Plasma concentrations were 22 and 15 mg/L at 24 and 48 hours after drug administration.
Calculate the area under the concentration time profile observed in the last question during day 2. (11 points)
A. 220 mg*hours/Liters
B. 330 mg*hours/Liters
C. 440 mg*hours/Liters
D. 670 mg*hours/Liters
E. None of the above

Back 40

C. 440 mg*hours/Liters

Front 41

True/False
The volume of distribution relates the amount of drug in the body to the amount of drug in the plasma

Back 41

False. concentration of drug in the plasma

Front 42

True/False
The volume of distribution relates the amount of drug in the body to the concentration of drug in the plasma

Back 42

True

Front 43

True/False
The volume of distribution relates the concentration of drug in the body to the concentration of drug in the plasma

Back 43

False. the amount of drug in the body

Front 44

True/False
The larger the volume of distribution, the smaller the dose necessary to achieve a certain starting concentration.

Back 44

False. larger the dose

Front 45

For the physiological changes listed below, select the induced changes on the pharmacokinetic parameters for a lipophilic, acid (pka), protein bound drug
Select the effect on kinetics
A) VD ↑
B) VD ↓
C) decreased rate of uptake into liver tissue
D) increased rate of uptake into liver tissue
E) none of the above
Decrease in pH of the blood

Back 45

D) increased rate of uptake into liver tissue
?

Front 46

For the physiological changes listed below, select the induced changes on the pharmacokinetic parameters for a lipophilic, acid (pka), protein bound drug
Select the effect on kinetics
A) VD ↑
B) VD ↓
C) decreased rate of uptake into liver tissue
D) increased rate of uptake into liver tissue
E) none of the above
Increase in tissue binding

Back 46

A) VD ↑

Front 47

For the physiological changes listed below, select the induced changes on the pharmacokinetic parameters for a lipophilic, acid (pka), protein bound drug
Select the effect on kinetics
A) VD ↑
B) VD ↓
C) decreased rate of uptake into liver tissue
D) increased rate of uptake into liver tissue
E) none of the above
Decrease in liver blood flow

Back 47

C) decreased rate of uptake into liver tissue

Front 48

For the physiological changes listed below, select the induced changes on the pharmacokinetic parameters for a lipophilic, acid (pka), protein bound drug
Select the effect on kinetics
A) VD ↑
B) VD ↓
C) decreased rate of uptake into liver tissue
D) increased rate of uptake into liver tissue
E) none of the above
Decreased blood flow through poorly perfused tissues (e.g. fat tissue)

Back 48

E) none of the above

Front 49

What of the following drug properties is beneficial for efficient distribution into poorly perfused organs (8 points)
a) The neutral (uncharged) species of a weak acid that is highly lipophilic.
b) The drug is uncharged at all times and highly hydrophilic
c) A strong base whose uncharged form is lipophilic
d) An uncharged drug with a small octanol/water partition coefficient
e) An acid with a pka of 7.4 and a large partition coefficient.
A) a, c, d
B) c, d, e
C) a,c,e
D) a, e
E) none of the above

Back 49

D) a, e

Front 50

True/False
Drug is distributed through permeability limited processes.
Lipophilic unionized drugs are likely to enter tissues relatively fast.

Back 50

True

Front 51

True/False
Drug is distributed through permeability limited processes.
The uptake of a hydrophilic drug into tissue can be increased significantly by increasing the blood flow through the tissue

Back 51

False

Front 52

True/False
Drug is distributed through permeability limited processes.
Tissues with low blood flow should take up lipophilic unionized drugs the best.

Back 52

True?

Front 53

True/False
The tissue uptake of a lipophilic unionized drug is more likely to be perfusion controlled.

Back 53

True

Front 54

True/False
Increase in plasma protein binding will decrease the volume of distribution of a lipophilic drug.

Back 54

True

Front 55

True/False
For a first-order elimination process, the same amount of drug is eliminated during a given time interval.

Back 55

False. different amount

Front 56

True/False
For a zero-order elimination process, the half-life (t1/2) depends on the drug concentration.

Back 56

True

Front 57

True/False
In a perfusion limited distribution, tissue membrane represents no barrier for the drug diffusion.

Back 57

True

Front 58

True/False
In a permeability limited distribution, blood flow is not important for rate of uptake.

Back 58

True

Front 59

True/False
Volume of distribution is the real tissue volume that contains the drug.

Back 59

False. real plasma concentration

Front 60

_______________ studies the influence of the dosage form of a drug on its pharmacological effect (or conc.).

Back 60

Biopharmaceutics

Front 61

_______________ studies what the body does to the drug. It describes the time course of drug and metabolite concentrations in the body.

Back 61

Pharmacokinetics

Front 62

The same amount of drug is eliminated during a given time interval.
a) Zero-order
b) First-order

Back 62

a) Zero-order

Front 63

The same fraction of drug is eliminated during a given time interval.
a) Zero-order
b) First-order

Back 63

b) First-order

Front 64

Given a one-compartment body-model, a concentration vs. time profile after an i.v. bolus shows a straight line on a linear scale.
a) Zero-order
b) First-order

Back 64

a) Zero-order

Front 65

Given a one-compartment body-model, a concentration vs. time profile after an i.v. bolus shows a straight line on a semi-log scale.
a) Zero-order
b) First-order

Back 65

b) First-order

Front 66

True/False
For a drug with high tissue binding, the volume of distribution will be very low.

Back 66

False. very high.

Front 67

True/False
Volume of distribution is not important to determine what loading dose is required.

Back 67

is important

Front 68

True/False
Drug A has 98% protein binding and has a narrow therapeutic index. Any change in the protein binding is not of significant consequence since already 98% drug is bound and very less is available for receptors.

Back 68

False. is of significant consequence

Front 69

True/False
If Drug A and Drug B are being administered at the same time then dose adjustment may be needed if there are drug interactions between A and B

Back 69

True

Front 70

True/False
In a one-compartment body model it is assumed that a drug distributes to all areas of
the body instantaneously.

Back 70

True

Front 71

True/False
Pharmacodynamics is the study of the time course of a drug’s absorption, distribution,
metabolism, and elimination.

Back 71

False. Pharmacokinetics
Pharmacodynamics refers to the relationship between concentration at the site of action and the resulting effect.

Front 72

True/False
The ke of a drug is 0.00333 min-1. After 2 hours 67% of the drug is remaining in the
body

Back 72

True
e-ke*t=fraction remaining e(-0.00333 min-1*60 min/hour*2 hours)=0.67

Front 73

True/False
The volume of distribution (Vd) of a lipophilic drug A is 800L.
Drug A is able to cross membranes

Back 73

True

Front 74

True/False
The volume of distribution (Vd) of a lipophilic drug A is 800L.
Drug A does not show any tissue protein binding

Back 74

False. does show

Front 75

True/False
The volume of distribution (Vd) of a lipophilic drug A is 800L.
Plasma protein binding is more pronounced than tissue binding

Back 75

False. less pronounced

Front 76

True/False
The volume of distribution (Vd) of a lipophilic drug A is 800L.
Vd indicates that this drug is highly metabolized in the tissue

Back 76

False. ?

Front 77

True/False
The volume of distribution (Vd) of a lipophilic drug A is 800L.
Drug A does not leave the plasma

Back 77

False. does leave

Front 78

True/False
The volume of distribution (Vd) of a lipophilic drug A is 800L.
Vd does reflect a real volume

Back 78

False. hypothetical

Front 79

Quinidine has a plasma protein binding, ranging from 70-90%. In patients with chronic liver disease plasma protein binding is decreased by 20%. How will the volume of distribution change? Use a plasma volume of 3 L and the fraction bound in plasma 85% (for normal patients), a tissue volume of 38 L and the fraction unbound in tissue 30% to calculate the volume of distribution in patients with liver disease.

Back 79

For normal patients:
Vd = Vp + Vt (fu/fut)
Vd = 3 L + 38 L(0.15/0.3) = 22 L

For patients with liver disease:
Plasma protein binding decreases by 20%, all the other parameters remain the same
New fraction bound: 0.85 * (1-0.20) = 0.85 * 0.8 = 0.68
Fraction unbound for liver patients: fu = 1-0.68= 0.32 (> normal patients’)
Vd = 3 L + 38 L (0.32 / 0.3) = 43.5 L

Front 80

True/False
For a zero-order elimination process, change in amount of drug in the body depends on the amount of drug in the body.

Back 80

False. ?

Front 81

True/False
For a first-order elimination process, the actual amount of drug eliminated per time unit is changing.

Back 81

True

Front 82

True/False
For a first-order elimination process, Ke and T1/2 do not change with dose.

Back 82

True

Front 83

True/False
Most lipophilic drugs are able to distribute throughout the body (entire extra- and intracellular space).

Back 83

True

Front 84

True/False
In a perfusion limited distribution, slower blood flow means slower uptake of drug into tissues.

Back 84

True

Front 85

True/False
In a permeability limited distribution, the degree of drug unionization will not affect the drug uptake.

Back 85

False. ?

Front 86

True/False
Only free drug is able to interact with receptors and is therefore of pharmacological interest.

Back 86

True

Front 87

True/False
In general, we can assume free drug in plasma is in equilibrium with free drug in tissue.

Back 87

True

Front 88

True/False
Volume of Distribution (Vd) is a hypothetical volume which relates the amount of a drug in the body to its plasma concentration

Back 88

True

Front 89

True/False
Vd can never exceed the total body water volume.

Back 89

False. ?

Front 90

True/False
Drug plasma protein binding and drug tissue binding are the main factors determining how fast a drug gets into tissues.

Back 90

False. ?

Front 91

True/False
A change in protein binding is especially important if the drug shows a high degree of protein binding.

Back 91

True

Front 92

True/False
Drug A is lipophilic. The apparent volume of distribution of drug A cannot be greater than 38 L

Back 92

False. can be

Front 93

True/False
Drug A is lipophilic and crosses membranes easily, while drug B is hydrophilic and crosses membranes poorly. At equilibrium, the free levels of drug B in tissue will always be higher than the free levels of drug B in plasma.

Back 93

False. ?

Front 94

Match the following units
Half–life (first order)

1. mg/hr
2. mg*L/hr
3. hr
4. mg*hr / L
5. mg/ L
6. L/ hr

Back 94

3. hr

Front 95

Match the following units
AUC

1. mg/hr
2. mg*L/hr
3. hr
4. mg*hr / L
5. mg/ L
6. L/ hr

Back 95

4. mg*hr / L

Front 96

How do fraction and amount of a drug eliminated through first-order kinetics change? Please, mark the right answer. (1 point)
1. Fraction changes, amount stays constant
2. Fraction stays constant, amount changes
3. Fraction changes, amount changes
4. Fraction stays constant, amount stays constant

Back 96

2. Fraction stays constant, amount changes

Front 97

How do fraction and amount of a drug eliminated through zero-order kinetics change? Please, mark the right answer. (1 point)
1. Fraction changes, amount stays constant
2. Fraction stays constant, amount changes
3. Fraction changes, amount changes
4. Fraction stays constant, amount stays constant

Back 97

1. Fraction changes, amount stays constant

Front 98

What is the difference in distribution of drugs into organs such as the heart and the lung compared to fat tissue and bone?

Back 98

Heart, lungs and kidneys are highly perfused organs compared to fat tissue and bone. For most drugs the rate of delivery from the circulation to a particular tissue depends greatly on the blood flow of the respective tissue. Therefore, drugs apparently distribute more rapidly to areas with higher blood flow.

Front 99

True/False
At equilibrium, the free drug concentrations in plasma and tissue will be identical.

Back 99

True

Front 100

True/False
Most drugs which are tightly bound to plasma protein tend to stay in the blood and thus have relatively low apparent volumes of distribution.

Back 100

True

Front 101

True/False
Drugs that are extensively distributed into specific tissue regions, such as chloroquine into the liver, tend to have quite small values for the apparent volume of distribution.

Back 101

False. tend to have quite large

Front 102

True/False
Disease state rarely affects the drug protein binding in the body.

Back 102

False. can affect

Front 103

True/False
The volume of distribution depends only on the degree of plasma binding.

Back 103

False. ?

Front 104

True/False
Drugs are generally less well distributed to highly perfused tissues.

Back 104

False. ?

Front 105

True/False
Ionized drug are hard to cross most membrane barriers.

Back 105

True

Front 106

True/False
Blood flow rate does not affect drug distribution rate at all.

Back 106

False. ?