1. A drug, given as a 100-mg single dose, results in a peak plasma concentration of 20 μg/mL. The apparent volume of distribution is (assume a rapid distribution and negligible elimination prior to measuring the peak plasma level): A. 0.5 L.
B. 1 L.
C. 2 L.
D. 5 L.
E. 10 L.
2. A drug with a half-life of 12 hours is administered by continuous intravenous infusion. How long will it take for the drug to reach 90 percent of its final steady state level? A. 18 hours.
B. 24 hours.
C. 30 hours.
D. 40 hours.
E. 90 hours.
3. Which of the following results in a doubling of the steady-state concentration of a drug? A. Doubling the rate of infusion.
B. Maintaining the rate of infusion but doubling the loading dose. C. Doubling the rate of infusion and doubling the concentration of the infused drug. D. Tripling the rate of infusion.
E. Quadrupling the rate of infusion.
4. A heart failure patient shows digoxin toxicity. She received 125 mcg as standard dose. Serum levels were reported to be 2ng/mL (2 mcg/L). Target therapeutic level is 0.8ng/mL. What dose should she receive? A. 25 mcg.
B. 50 mcg.
C. 75 mcg.
D 100 mcg.
E. 125 mcg.
5. The addition of glucuronic acid to a drug:
A. Decreases its water solubility.
B. Usually leads to inactivation of the drug.
C. Is an example of a Phase I reaction.
D. Occurs at the same rate in adults and newborns.
E. Involves cytochrome P450.
6. Drug X produces maximal contraction of cardiac muscle in a manner similar to epinephrine. Drug X is considered to be a(n)
B. Partial agonist.
C. Competitive Antagonist.
D. Irreversible antagonist.
E. Inverse agonist.
7. Which of the following statements is correct?
A. If 10 mg of Drug A produces the same response as 100 mg of Drug B, Drug A is more efficacious than Drug B.
B. The greater the efficacy, the greater the potency of a drug. C. In selecting a drug, potency is usually more
important than efficacy.
D. A competitive antagonist increases the ED50.
E. Variation in response to a drug among different individuals is most likely to occur with a drug showing a large therapeutic index. Answer: D
8. Variation in the sensitivity of a population of individuals to increasing doses of a drug is best determined by which of the following? A. Efficacy.
C. Therapeutic index.
D. Graded dose–response curve.
E. Quantal dose–response curve.
9. Which of the following statements most accurately describes a system having spare receptors? A. The number of spare receptors determines the maximum effect. B. Spare receptors are sequestered in the cytosol.
C. A single drug–receptor interaction results in
many cellular response elements being activated.
D. Spare receptors are active even in the absence of agonist. E. Agonist affinity for spare receptors is less than their affinity for nonspare receptors. Answer:
10. A patient was given a 200 mg dose of a drug IV, and 100 mg was eliminated during the first two hours. If the drug follows first -order elimination kinetics, how much of the drug will remain 6 hours after its administration? A. None
E. 100 mg