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

2. 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.

3. Lipophilic drugs are generally taken up fast by highly perfused organs.

4. Ionized and lipophilic drugs are most likely to cross most membrane barriers.

5. Drugs with a high tissue binding always have a large volume of distribution.

Question Set II

6. 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, {C = 33 * e^-0.116*t (Unit: mg/L)}, where C represents U5127 concentration at time t (hr). Calculate U5127 volume of distribution.

45 L

0.76L

38 L

18 L

None of the above

Explanation of answer

Question Set III

7. 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.)

 

Increase to 37.74 L

Increase to 22.54 L

Stay the same as 13.86 L

Stay the same as 46.43 L

Decrease to 11.69 L

Explanation

Question Set IV True or False

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

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

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

Question Set V True or False/p>

 

Figure A	Figure B

11. Figure A shows a first order elimination process, and ke has a unit of hr -1.

12. Figure B shows a zero order elimination process, and ke has a unit of hr -1.

13. In Figure B, the fraction of drug eliminated per hour is constant.

14. In Figure A, the eliminated drug amount per hour is changing.

15. In Figure A, the rate of elimination is dependent of amount of drug in body.

Questions Set VI

16. 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)	Concentration (mg/L)
4	2.5
10	0.5

Calculate the AUC 0-¥. (Assume first-order elimination for gentamicin, and please use trapezoidal rule to calculate.)

 

30.5 mg/L*hr

34.1 mg/L*hr

19.6 mg/L*hr

9.0 mg/L*hr

none of the above

 

17. A 100 mg dose of a drug was administered to two patients by IV bolus injection. For patients A and B, the initial concentrations (C 0) 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.

Patient B has more fat tissue than Patient A.

Plasma unbound fraction in Patient B is higher than that in Patient A.

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

Patient B has larger volume of distribution than Patient A.

None of Above

18. 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

Increase

Decrease

No change

Not enough information given to answer question

19. Drug A follows a perfusion-limited distribution. Drug concentratin-time profiles from several tissues (A, B, and C) were plotted as below. Which of the following answer is correct?

Tissue A: Brain; Tissue B: Skin; Tissue C: Liver

Tissue A: Skin; Tissue B: Kidneys; Tissue C: Fat

Tissue A: Lungs; Tissue B: Muscle; Tissue C: Fat

Tissue A: Kidneys; Tissue B: Fat; Tissue C: Liver

Tissue A: Skin; Tissue B: Muscle; Tissue C: Fat