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Monday - Wednesday - Friday 11:00 - 11:50 a.m.
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PHAR 319: Biopharmaceutics/Pharmacokinetics
Mid-term II, May 23,1997
Total 100 points
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Monday - Wednesday - Friday 11:00 - 11:50 a.m.
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Please choose the best answer of those provided. For numerical answers, choose "none of the above" if your answer is not within ± 5% of any available numerical choice.
Use the following information for Questions 1-4.
WW, a 72-year old female with a heart valve replacement is 5'3 " tall and weighs 60 kg. She developed arterial fibrillation yesterday and at 9:00 a.m. yesterday she was given a 1.0 mg IV loading dose of digoxin (divided appropriately).
I . What is the ideal body weight for WW?
a. 52.4 kg
b. 60.0 kg
C. 47.16 kg
d. 132.0 pounds
e. None of the above.
2. WW, question 1, has a SCR=1.3 mg%. What is her creatinine clearance?
a. 38 ml/min
b. 32.3 ml/min
C. 105 ml/min
d. 43.5 ml/min
e. None of the above.
3. What digoxin plasma concentration is the loading does (question # 1) expected to produce in WW?
a. 1.37 mcg/L
b. 1.50 mcg/L
C. 2.61 mcg/L
d. 3.34 mcg/L
e. None of the above.
4. What is the expected digoxin clearance in WW above?
a. 66.8 L/day
b. 56.8 L/day
C. 46.4 L/day
d. 166 L/day
e. None of the above.
5. If a patient has a digoxin clearance of 107 L/day and a digoxin Vd of 300 L, then what is the half-life of digoxin?
a. 1.6 days
b. 2.0 days
C. 3.3 days
d. 4.8 days
e. None of the above.
6. For the patient in question 5, if the Cp of digoxin is 3.0, how long will it take until the Cp decreases to 1.0?
a. 1.94 days
b. 3.08 days
C. 3.88 days
d. 5 half-lives
e. None of the above.
7. For the patient in question 5, what average plasma concentration of digoxin will be produced at steady-state if the dose is 0. 125 mg orally every morning?
a. 1.2 mcg/L
b. 1.37 mcg/L
C. 1.5 mcg/L
d. 0.93 mcg/L
e. None of the above.
Chlorpromazine hydrochloride (CPZ) is a psychoactive agent with t1/2 = 30 hours, Vd = 21 L/kg, F = 0.32 and S = 0.9. Use this information for questions 8-11
8. What oral dose of chlorpromazine hydrochloride (CPZ) should be given every 24 hours to produce`c = 125 ng/ml?
a. 562 mcg/kg
b. 5.05 mg/kg
c. 3.36 mg/kg
d. Cannot be estimated from data given.
e. None of the above.
9. The oral maintenance dose of CPZ has been 375 mg q 6h for a 60 kg psychiatric institutionalized patient. Estimate the cp ss maximum peak concentration for this patient.
a. 662 mcg/L
b. 85.7 mcg/L
c. 241 mcg/L
d. 85.7 ng/L
e. None of the above.
10. What would be the average steady state plasma drug concentration (`c ) for the patient in question 9?
a. 50 ng/ml
b. 165 ng/ml
c. 450 ng/ml
d. 620 ng/ml
e. None of the above.
11. A 70 kg patient with a CPZ plasma concentration of 100 ng/ml took five 200 mg tablets all at once. If drug absorption is rapid, what is the estimated CPZ plasma concentration after the five tablets?
a. 1,058 ng/ml
b. 143.6 ng/ml
c. 305.9 ng/ml
d. 1,765 ng/ml
e. None of the above.
12. A 56 yo, 60 Kg patient with a history of alcohol abuse and liver damage is to receive lidocaine IV for management of acute ventricular arrhythmias. If lidocaine is infused at a rate of 1 mg/min, what is the plasma drug concentration 2 hours after beginning the infusion?
a. 2.4 mcg/ml
b. 1.3 mcg/ml
c. 0.58 mcg/ml
d. 3.27 mcg/ml
e. None of the above.
13. The patient in question 12 did not respond well to the lidocaine infusion at steady state, and analysis of a blood sample showed the `c of lidocaine was 2.4 mcg/ml. Calculate a new infusion rate to produce a Cp steady state (`c ) of 4 mcg/ml?
a. 3.3 mg/min
b. 4.0 mg/min
c. 0.6 mg/min
d. 1.67 mg/min
e. None of the above.
14. What is the lidocaine clearance in the patient in question 13?
a. 600 ml/min
b. 1440 ml/min
c. 360 ml/min
d. 720 ml/min
e. None of the above.
15. MZ, a 72-year old female, IBW 52 Kg, and creatinine clearance of 50 ml/min received a 1000 mg IV loading dose of procainamide over 20 minutes. She is a fast acetylator. What is the expected drug concentration (Cp) at the end of the infusion?
a. 108 mg/L
b. 8 mg/L
c. 6 mg/L
d. 7.42 mg/L
e. None of the above.
16. The patient in question 15 also received 500 mg oral sustained release procainamide every 8 hours around the clock. What is her expected`c for procainamide at steady state?
a. 1.9 mg/L
b. 4 mg/L
c. 6 mg/L
d. 8 mg/L
e. None of the above.
17. If a patient with a total procainamide clearance of 15 L/hr and a Vd of 140 L receives 1000 mg of sustained release procainamide every 8 hours, what is the expected Cp max at steady state?
a. 3.7 mg/L
b. 12.3 mg/L
c. 6.1 mg/L
d. 7.5 mg/L
e. None of the above.
18. Gentamicin (S = 1.0) is an antibiotic with a Vd of 0.25 L/kg in non-obese patients and a clearance which is equal to the clearance of creatinine. RW is a 30 yo, 70 Kg IBW female with a ClCR = 6.06 L/hr. If she receives a 100 mg dose of gentamicin by zero order infusion over 30 minutes, what is the expected plasma concentration of gentamicin one hour after the infusion started (i.e., one-half hour after the infusion was completed)?
a. 4.4 mg/L
b. 5.3 mg/L
c. 5.7 mg/L
d. 33 mg/L
e. None of the above.
19. A patient is receiving one 500 mg tablet of drug X once every 8 hours. The Cp max is 100 and the Cpmin is 5O. What is the Cp produced if the patient takes the dose at the correct time, but takes three tablets instead of one tablet?
a. 150
b. 200
c. 250
d. 1500
e. None of the above.
20. If the dose for the patient in question 19 is changed to be 1000 mg taken every 12 hours, how long will it take to reach steady-state?
a. 60 hours
b. 40 hours
c. 24 hours
d. Cannot tell from the information given.
e. None of the above.