General Pharmacology MCQs
Pharmacokinetics :
1. Which one of the following statements is correct?
A. Weak bases are absorbed efficiently across the epithelial cells of the stomach.
B. Coadministration of atropine speeds the absorption of a second drug.
C. Drugs showing a large Vd can be efficiently removed by dialysis of the plasma.
D. Stressful emotions can lead to a slowing of drug absorption.
E. If the Vd for a drug is small, most of the drug is in the extraplasmic space.
2. Which one of the following is true for a drug whose elimination from plasma shows first-order kinetics?
A. The half-life of the drug is proportional to the drug concentration in plasma.
B. The amount eliminated per unit of time is constant.
C. The rate of elimination is proportional to the plasma concentration.
D. Elimination involves a rate-limiting enzymic reaction operating at its maximal velocity (Vm).
E. A plot of drug concentration versus time is a straight line.
3. A patient is treated with drug A, which has a high affinity for albumin and is administered in amounts that do not exceed the binding capacity of albumin. A second drug, B, is added to the treatment regimen. Drug B also has a high affinity for albumin but is administered in amounts that are 100 times the binding capacity of albumin. Which of the following occurs after administration of drug B?
A. An increase in the tissue concentrations of drug A.
B. A decrease in the tissue concentrations of drug A.
C. A decrease in the volume of distribution of drug A.
D. A decrease in the half-life of drug A.
E. Addition of more drug A significantly alters the serum concentration of unbound drug B.
4. 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.
5. Drugs showing zero-order kinetics of elimination:
A. Are more common than those showing first-order kinetics.
B. Decrease in concentration exponentially with time.
C. Have a half-life independent of dose.
D. Show a plot of drug concentration versus time that is linear.
E. Show a constant fraction of the drug eliminated per unit of time.
6. 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.
7. A drug with a half-life of 12 hours is administered by continuous IV infusion. How long will it take for the drug to reach ninety percent of its final steady-state level?
A. 18 hours.
B. 24 hours.
C. 30 hours.
D. 40 hours.
E. 90 hours.
8. 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.
Pharmacodynamics
9. 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.
10. 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.
B. Potency.
C. Therapeutic index.
D. Graded dose-response curve.
E. Quantal dose-response curve.
11. 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.
