Dose Op 2 Final

Front 1

Which combination of the following pharmacokinetic changes best describes the elderly and neonates? (These groups share similar PK characteristics.)
1. Low renal clearance
2. Longer half-lives
3. Low metabolic clearance
4. Decreased protein binding
5. Relatively less body water

A. 1 & 4
B. 1, 2, 3& 4
C. 1, 3, 4 &5
D. 1, 4, &5
E. all of the above

Back 1

B. 1, 2, 3& 4

Front 2

Which of the following changes goes along with a decreased clearance and no change in volume of distribution?
A. shorter half-life, higher steady state concentration
B. longer time to steady state, shorter half-life
C. longer time to steady state, lower steady state concentration
D. increased initial concentration after an i.v. bolus, longer time to steady state
E. longer time to steady state, higher steady state concentration

Back 2

E. longer time to steady state, higher steady state concentration

Front 3

Please mark the CORRECT statements about Digoxin.
1) Digoxin is a PGP-substrate.
2) Digoxin follows a one compartment body model.
3) Digoxin levels are increased in patients with hyperthyroid function.
4) Digoxin distributes rapidly into the myocardial tissue.
5) Digoxin is only renally eliminated
A. 1, 3, 4
B. 2, 3, 5
C. 1, 2, 3, 4
D. 1, 2, 4, 5
E. None of the above

Back 3

E. None of the above

Front 4

With aminoglycosides usally Cmax and Cmin are calculated using IV infusion equations. However, with vancomycin it is acceptable to use IV bolus equations to calculate Cmax and Cmin instead of IV infusion equations. Why is it justified to use these equations with vancomycin compared to aminoglycosides?
A) Vancomycin has a lower clearance which results in a smaller fluctuation.
B) Vancomycin has a smaller volume of distribution which results in a larger flucutation.
C) Vancomycin has a higher clearance which results in a larger half-life.
D) Vancomycin has a smaller half-life which results in a smaller fluctuation.
E) Vancomycin has a longer half-life which results in a smaller fluctuation.

Back 4

E) Vancomycin has a longer half-life which results in a smaller fluctuation.

Front 5

Which of following statement is FALSE about phenytoin?
A) The metabolism of phenytoin is capacity–limited which means that the clearances values increase with increasing plasma concentrations (at high concentrations).
B) The bioavailability of phenytoin is difficult to evaluate because of the drug’s capacity–limited metabolism.
C) The clinical usefulness of the phenytoin half-life is limited because the time required to achieve steady state can be much longer than the usual 3 to 5 times the apparent half-life.
D) When the oral loading dose of phenytoin is divided into three separate doses, the possibility of nausea and vomiting decreases. And the time to peak concentration decreases too.
E) All of the above are true

Back 5

A) The metabolism of phenytoin is capacity–limited which means that the clearances values increase with increasing plasma concentrations (at high concentrations).

Front 6

What is the general reason that the ultimate desired maintenance dose of Carbamazepine is much higher than the beginning dose?
A) Pharmacodynamic drug tolerance
B) Disease progression
C) Metabolic enzyme autoinduction
D) Renal function increased
E) Carbamazepine is a high hepatic extraction drug

Back 6

C) Metabolic enzyme autoinduction

Front 7

Which of the following statements is FALSE based on the volume of distribution in obese patients.
A) Hydrophilic drugs display little change in the volume of distribution.
B) The volume of distribution is based on the lipophilicity of the drug.
C) Lipophilic drugs display an increase in the volume of distribution.
D) Hydrophilic drugs display a decrease in the volume of distribution per kilogram.
E) Lipophilic drugs display a decrease in the volume of distribution per kilogram.

Back 7

E) Lipophilic drugs display a decrease in the volume of distribution per kilogram.

Front 8

Select all TRUE statements. 1) Clearance can be thought of as a volume of plasma from which the drug is removed in a specific time period. 2) If elimination from the central/body compartment is first order we can assume that a one compartment pharmacokinetic model is applicable. 3) Given Cp = Cp0·e-ke·t, and two data points (t1, Cp1) and (t2, Cp2), the elimination rate constant can be calculated as the slope [= (lnCp2 - lnCp1)/(t2-t1)] multiplied by -1. 4) If the infusion rate constant (k0) is doubled the steady state plasma concentration (Cpss) will be doubled, assuming the other parameters are unchanged. 5) Appropriate unit for AUC is mg·hr·L.

A) 1, 2, 3
B) 2, 3, 4
C) 2, 3, 5
D) 1, 3, 4
E) 1, 2, 5

Back 8

D) 1, 3, 4

Front 9

Which combination of the following factors makes the serum creatinine level a good choice to estimate renal function?
1) Creatinine is endogenous 2) Creatinine is only eliminated by the kidneys 3) Creatinine shows no plasma protein binding 4) Creatinine urinary excretion rate is not affected by the disease state 5) Creatinine is constantly formed in muscles
A) 1, 2 & 4
B) 1, 2, 3 & 5
C) 1, 3, 4 & 5
D) 2, 3, 4 & 5
E) All of the above

Back 9

B) 1, 2, 3 & 5

Front 10

Which of the following statements about body weight in pharmacokinetics are correct?
1) We can roughly assume liver and kidney function are proportional to body weight.
2) Effects of obesity on volume of distribution depend on the lipophilicity of the drug.
3) Physical and chemical properties of drugs determine the impact of body weight on pharmacokinetics.
4) In general, we should always use IBW for drug recommendations.
5) Weakly or moderately lipophilic drugs are poorly distributed in obese patients.

A) 1, 2, 3, 4 & 5
B) 1, 2 & 4
C) 1, 2, 3, & 5
D) 1, 3, 4 & 5
E) 2, 3, 4 & 5
Version

Back 10

C) 1, 2, 3, & 5

Front 11

J.D., a 45 year-old, 87 kg male, with CHF, was admitted to the hospital for his arrhythmia. A bolus dose of lidocaine was given to achieve an immediate response (C0 = 3mg/L). After the bolus, a followed 250 mg short-term infusion will start for 15 minutes. One hour after the bolus, a maintenance infusion will start. What might be the potential purpose to give the short-term infusion immediately?
A) Lidocaine has very short terminal half life, so we need to keep infusing the drug to maintain the same drug effect
B) Lidocaine can cause pharmcodynamic tolerance, so we need to keep increasing the drug concentration to maintain the same drug effect
C) Lidocaine can cause seizures if the initial concentration is above 3 mg/L, so we need to increase the drug concentration slowly to achieve a higher therapeutic concentration
D) Lidocaine has very rapid initial distribution, so we need to complement the drug losing from the central compartment to maintain the drug effect
E) All of above
Version

Back 11

D) Lidocaine has very rapid initial distribution, so we need to complement the drug losing from the central compartment to maintain the drug effect

Front 12

A study was conducted to assess the effect of thyroid diseases on Digoxin pharmacokinetics. Three groups of subjects received the same amount of Digoxin via intravenous administration. Group I: (Subjects with Myxedema); Group II: (Subjects with Euthyroid state); Group III: (Subjects with Hyperthyorism) Serum Digoxin concentrations were measured, and concentration-time profiles were assessed. Which of following statement is FALSE?
A) Subjects with hyperthyroism have the highest apparent volume of distribution.
B) If multiple doses are applied to the subjects, the time required to reach steady state will be the same for all three groups.
C) Both clearance and volume of distribution are affected by thyroid disease.
D) If subjects with hyperthyroism have a increased glomerular filtration rate, and renal function is the major factor associated with digoxin clearance, patients with intrinsic renal failure will have a decreased digoxin clearance.
E) When multiple doses are required, hyperthyroid patients will take smaller loading doses in order to achieve the same steady state concentrations as those in euthyroid state.

Back 12

E) When multiple doses are required, hyperthyroid patients will take smaller loading doses in order to achieve the same steady state concentrations as those in euthyroid state.

Front 13

During a phase I clinical trial, a single 500mg tablet of drug X was given orally. It was found that drug X has a total clearance of 80L/h and was only eliminated by CYP2D6 metabolism in the liver.
As the new member in the research team you are now asked to interpret these results. Which statement is true?
1. This drug is a low extraction drug.
2. Drug X should not be administered together with CYP2D6 inducers since they will significantly affect the metabolism of drug X.
3. A change in plasma protein binding will affect the clearance of drug X.
4. A change in plasma protein binding will affect the bioavailability of drug X.

Back 13

4. A change in plasma protein binding will affect the bioavailability of drug X.

Front 14

Methotrexate can be given intrathecally as a chemotherapy. List some basic factors to consider prior to giving methotrexate intrathecally.

Back 14

1.
CL: Renal dysfunction
2.
DDI: Other drugs that alter methotrexate clearance
3.
Disease state: Defects in cerebrospinal flow (meningeal leukemia)
4.
CNS methotrexate level not to exceed 10-8 molar, therefore monitoring required prior to second dose

Front 15

Procainamide is metabolized to an active metabolite, ____________, and is formed by the process of ________________.(5 points)
A.) MEGX; alkylation
B.) MEGX; acetylation
C.) GX; acetylation
D.) NAPA; alkylation
E.) NAPA; acetylation

Back 15

E.) NAPA; acetylation

Front 16

Which of the following changes goes along with a decreased clearance and no change in volume of distribution? (5 pts.)
A) shorter half-life, higher steady state concentration
B) longer time to steady state, shorter half-life
C) longer time to steady state, lower steady state concentration
D) increased initial concentration after an i.v. bolus, longer time to steady state
E) longer time to steady state, higher steady state concentration

Back 16

E) longer time to steady state, higher steady state concentration

Front 17

Once daily aminoglycoside therapy rationale includes which of the following: (5 pts)
1 Treatment is more cost effective
2 Reduced toxicity due to lower peak concentrations
3 Reduction in post-antibiotic effect
4 Bacteria develop active resistance for 14-30 hours
A) 1, 2, 3, and 4
B) 1, 2 and 4
C) 1 and 4
D) 1, 3 and 4
E) 3 and 4

Back 17

C) 1 and 4

Front 18

In most cases, aminoglycoside is given by i.v. short term infusion. However, for a
certain group of patients, a bolus dose model could be used satisfactorily for
prediction of the aminoglycoside concentrations. These patients are:
(5 pts)
a. young adults
b. children
c. patients with decreased liver function
d. men
e. patients with decreased renal function

Back 18

e. patients with decreased renal function

Front 19

Half life (t 1/2) is a common parameter in PK study. A longer half‐life of a drug will indicate:
A) a larger total body clearance.
B) more fluctuation can be expected at steady state.
C) a longer time to reach steady state
D) a shorter dosing interval to maintain a certain fluctuation.
E) a smaller volume of distribution

Back 19

C) a longer time to reach steady state

Front 20

What is the pharmacokinetic parameter that should be monitored for vancomycin
therapy to achieve the desired efficacy?
A. Clearance
B. AUC
C. Peak concentration
D. Trough concentration
E. Vd

Back 20

D. Trough concentration

Front 21

Which of the following statements are TRUE?
1 The total body water (in % of body weight) in neonates is usually smaller than in adults
2 The glomerular filtration rate (GFR) in neonates is usually larger than in adults
3 The effect of body weight on volume of distribution does not depend on the lipophilicity of the drug
4 Aminoglycosides cannot pass membranes very well because of their low protein binding
A 1
B 2
C 3
D 4
E None of the above

Back 21

E None of the above

Front 22

Which of the following statements about aminoglycosides are TRUE?
1 Therapeutic Drug Monitoring (TDM) is never recommended for aminoglycosides
2 Aminoglycosides are mostly cleared by the kidney
3 The creatinine clearance of a patient can be used to estimate his total systemic clearance
4 The volume of distribution of aminoglycosides is usually 0.25 L
5 Once‐a‐day dosing is never recommended for aminoglycosides
A 1, 5
B 2, 3
C 2, 3, 4
D 1, 2, 3, 4
E 2, 4

Back 22

B 2, 3

Front 23

How will an increase in tissue binding affect the clearance (CL), bioavailability (F), AUC, and half‐life (t1/2) of a low‐extraction drug? (Please note that ↔ means no change)
A: ↑ CL, ↓F, AUC↓, ↓ t1/2
B: ↔ CL, ↑F, AUC ↑, ↔ t1/2
C: ↔CL, ↔ F, AUC↔,↑ t1/2
D: ↓ CL, ↔ F, AUC ↑, ↑ t1/2
E: ↑ CL, ↑ F, AUC ↓, ↓ t t1/2

Back 23

C: ↔CL, ↔ F, AUC↔,↑ t1/2