إمتحان Pharmacokinetics الدور الثاني 2007 مرحلة خامسة - كلية الصيدلة - جامعة بغد

College of Pharmacy/University of Baghdad
Clinical Pharmacy Dept.

5th year. Clinical Pharmacokinetic .Second trial. Final exam. 2007.Time : 3 hours.

Q1

A-(5 marks) Mention Five Sources of Errors in TDM ?

B-(5 marks) Enumerate Ten drugs that are commonly monitored in hospital setting?

C-(6 marks) What did we mean by pseudolinear pharmacokinetics?

D-(6 marks) what is the optimum Sampling Time for measuring the peak concentration of aminoglycosides :

1- If they are given as 1-hour infusion.

2- If they are given as 1/2 hour- infusion.

(Rationalize your answer)

Q2

A-(10 marks) knowing that Phenytoin follow Michaelis-Menten or saturable pharmacokinetics. What did this mean ?

and what are the clinical monitoring parameters for Phenytoin?

B-(8 marks) TD is a 50 years man who has simple partial seizure. He needs therapy with oral phenytoin. The patient is given a pre------ion of 400 mg /day of extended release phenytoin capsule for 1 month.
Current phenytoin steady state conc. is 6.2 mg/ L. What will be the expected new phenytoin conc. if the dose of phenytoin is increased to 500 mg /day?

You may benefit from the following equation:
( Dnew / Css new = Dold / C ss old )

Q3

LG is a 53 years old , 69 kg , 178 cm , man who has chronic bronchitis .He was prescribed an I.V Aminophylline 50 mg/h . The serum conc. of theophylline after 24 hours of this regimen is 7.4 mg/ L.

A-(10 marks) Compute an Aminophylline booster dose to provide a steady state conc. of 11 mg/ L?

B-(5 marks) Compute a new Aminophylline infusion to provide a steady state conc. of 11 mg/ L. using pharmacokinetic parameter method?
You may benefit from the following information and equations:
V= 0.5 L/kg
Css = [ K0 . S] / CL
S=0. 8
Where K0 is the Theophylline dose in mg/ hour.

C-(5 marks) What are the disease states and conditions that affect the pharmacokinetic parameters of Theophylline ?

Q4

OF is a 71 years old, 60 kg , female with ventricular fibrillation, Who requires therapy with I.V. lidocaine. She has normal liver function and severe heart failure (NYHA class IV).

A-(10 marks) Suggest an initial intravenous dosage regimen (loading dose and maintenance dose)to achieve a steady lidocaine conc. of 5 mg/L.

B-(15 marks)The above patient (Patient OF) was prescribed I.V lidocaine at 2 mg / min after receiving a loading dose ,the current steady state conc. is 6.7 mg /L.
Compute a new lidocaine continuous infusion rate that provides a steady state conc. of 4 mg /L using:

1-Linear pharmacokinetic method.
2-pharmacokinetic parameter method.

You may benefit from the following information:
Vc = 0.3 L/kg
Varea = 1.0 L/Kg
T 1/2=2 hours
Ke = 0.693/ T 1/2
CL = K . Varea
LD = Css . Vc
Ko =Css . CL
( Dnew / Css new = Dold / Css old )

Q5

A-(7.5 marks) Put (T) for the true statements and (F) for the false statements and correct the false one.

1-High vancomycin n peak steady conc. lead to an increased risk of nephrotoxicity. while high trough steady conc. lead to an increased risk of Ototoxicity.

2-Dosing regimen may be affected by the available strength of tablets and capsule.

3-Dialysis may affect the pharmacokinetics of some drugs.

4-Measuring serum creatinine is important in the monitoring of aminoglycosides therapy.

5-During an acute manic attack, CL of lithium can decrease by as much as 50% .

B-(7.5 marks) FD is a 9 years old, 35 kg, 137 cm, girl who has absence seizure. She needs therapy with oral Ethosuximide .She is given a Rx of 350 mg every 12 hours of Ethosuximide syrup for 1 month. Current Ethosuximide steady state conc. is 55 mg/ L. compute a revised Ethosuximide dose to provide a steady state conc. of 90 mg/ L. using: pharmacokinetic parameter method.

You may benefit from the following information