General Pharmacology MCQs
1. The antimicrobial drug, tetracycline, is found to be therapeutically effective when 250mg of drug are present in the body. The T1/2 of tetracycline is 8 hours. What is the correct rate of infusion?
A. 7 mg/hour.
B. 12 mg/hour.
C. 22 mg/hour.
D. 37 mg/hour.
E. 45 mg/hour.
2. A drug with a half life 8 hours is administered by continuous intravenous infusion. How long will it take for the drug to reach 90% of its final steady-state level?
A. 12 hours.
B. 18 hours.
C. 25 hours.
D. 30 hours.
E. 40 hours.
3. A drug has an elimination rate constant ( Ke ) of 0.1 hr-1. It is administered in a dose of 250 mg every 8 hours. Practically the steady state level will be attained after:
A. First dose .
B. Two doses.
C. Four doses.
D. Five days.
E. Seven days.
 A patient with heart disease require immediate treatment with the antiarrythmic drug procainamide. The text book lists the following pharmacokinetic value for procainamide in a 70-kg person : Vd = 80L, Cl = 25 L/hour, and therapeutic concentration = 5mg/L :
Answer the coming 3 questions in relation to the case
4. What intravenous loading dose should be administered ?
A. 180 mg
B. 225 mg
C. 400 mg
D. 520 mg
E. 800
5. What constant intravenous infusion rate should be used to maintain the therapeutic concentration of 5mg/L ?
A. 90 mg/hour
B. 125 mg/hour
C. 180 mg/hour
D. 250 mg/hour
E. 650 mg/hour
6. What is the predicted half-life of procainamide in this patient ?
A. 2.22 hrs
B. 2.4 hrs
C. 3.6 hrs
D. 5.0 hrs
E. 10.0 hrs
7. A drug with a half life 12 hours is administered by continuous intravenous infusion. How long will it take for the drug to reach 90% of its final steady-state level?
A. 18 hours.
B. 24 hours.
C. 30 hours.
D. 40 hours.
E. 90 hours.
8. A drug with a half-life 10 hours is administered by continuous intravenous infusion. How long will it take for the drug to reach 75% of its final steady-state level?
A. 10 hours.
B. 20 hours.
C. 25 hours.
D. 33 hours.
E. 48 hours.
A 35-kg child with heart disease requires immediate treatment with the antiarrhythmic drug procainamide. The textbook lists the following pharmacokinetic values for procainamide in a 70-kg person: Vd= 160 L, Cl= 50 L/hour, oral availability 83% and therapeutic concentration 5 mg/L.
Answer the coming 3 questions in relation to this case:
9. What intravenous loading dose should be administered?
A. 180 mg.
B. 225 mg.
C. 400 mg.
D. 520 mg.
E. 600 mg.
10. What constant intravenous infusion rate should be used to maintain the therapeutic concentration of 5 mg/L?
A. 90 mg/hour.
B. 125 mg/hour.
C. 180 mg/hour.
D. 217 mg/hour.
E. 650 mg/hour.
11. What is the predicted half-life of procainamide in this child?
A. 2.22 hrs.
B. 2.4 hrs.
C. 3.6 hrs.
D. 5.0 hrs.
E. 10.0 hrs
12. A 19-year-old woman is brought to the hospital with sever asthmatic wheezing. You decide to use IV theophyline for treatment. The pharmacokinetics of the theophyline include the following average parameters: Vd 35 L, Cl 48 ml/min, half-life 8 hours. If an IV infusion of theophyline is started at a rate of 0.48 mg/min, how long will it take to reach 93.75 of the final steady state?
A. Approximately 48 minutes
B. Approximately 5.8 hours.
C. Approximately 6 hours.
D. Approximately 8 hours.
E. Approximately 32 hours.
A patient is admitted to General Hospital with pneumonia due to gram-negative bacteria. The antibiotic tobramysin is ordered. The CL and Vd of tobramysin in the patient are 80 mL/min and 50 L, respectively. Answer the coming 2 questions
13. What maintenance dose should be administered intravenously every 6 hours to eventually obtain average steady state plasma concentration of 6 mg/L?
A. 0.24 mg.
B. 0.48 mg.
C. 0.60 mg.
D. 10.0 mg.
E. 50 mg.
14. If you wish to give the patient an IV loading dose to achieve the therapeutic plasma concentration of 6 mg/L rapidly, how much should be given?
A. 10 mg.
B. 100 mg.
C. 150 mg.
D. 200 mg.
E. 300 mg.
15. A normal volunteer will receive a new drug in a phase 1 clinical trial. The clearance and volume of distribution of the drug in this subject are 1.386 L/h and 80 L, respectively. The half-life of the drug in this subject will be approximately:
A. 90 hr.
B. 80 hr.
C. 40 hr.
D. 20 hr.
E. 2 hr.
16. Gentamicin is often given in intermittent IV bolus doses of 100 mg three times a day to achieve target peak plasma concentration of about 5 mg/L. Gentamicin’s clearance (normally 5.4 L/h/70kg) is almost entirely by glomerular filtration. Your patient, however, is found to have a creatinine clearance one-third of normal. Your initial dosage regimen for this patient would probably be:
A. 33 mg three times daily.
B. 66 mg three times daily.
C. 72 mg three times daily.
D. 100 mg twice daily.
E. 150 mg twice daily.
17. A narcotic addict is brought to the emergency room in a deep coma. His friends state that he took a large dose of morphine 6 hours earlier. An immediate blood analysis show a morphine blood level of 0.25 mg/L. Assuming that the pharmacokinetics of morphine in this patient are Vd 200 L and half life 3 hours, how much morphine did the patient inject 6 hours earlier?
A. 25 mg.
B. 50 mg.
C. 100 mg.
D. 200 mg.
E. Too few data to predict.
18. The total body clearance of a drug is 50 ml/min. the optimal IV infusion rate to maintain a plasma level of 10 μg/ml is:
A. 0.1 mg/min
B. 0.2 mg/min
C. 0.5 mg/min
D. 0.75 mg/min
E. 1 mg/min
19. A drug has a volume of distribution of 0.27 L/Kg, what is the loading dose (mg/Kg) to attain a peak plasma level of approximately 10 μg/ml?
A. 0.05 mg/Kg
B. 0.1 mg/Kg
C. 1.0 mg/Kg
D. 2.5 mg/Kg
E. 4 mg/Kg
20. What would be the half life of a drug with a volume of distribution of 0.15 L/Kg and a clearance of 48 ml/min in a 70 Kg man?
A. 1.5 hr
B. 2.5 hr
C. 4.5 hr
D. 8.5 hr
E. 24 hr
21. What orally administered loading dose would achieve a plasma concentration of 10 μg/ml for a drug that has a volume of distribution (Vd) of 100 L and 75% bioavailability?
A. 1.3 mg
B. 3.6 mg
C. 12 mg
D. 24 mg
E. 48 mg
22. A drug dose repeated at the elimination half-life, just prior to the third administration, approaches the steady state of further administrations by what percentage?
A. 50%.
B. 62.5%.
C. 75%.
D. 82.5%.
E. 90%.
