### 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%.