Pharmacokinetics and Pharmacodynamics Practice Questions
20 free Pharmacokinetics and Pharmacodynamics practice questions for the USMLE Step 1, each with the correct answer and a detailed explanation. Open any question below, or take the full set as an interactive quiz.
Questions
20 questions
All Pharmacokinetics and Pharmacodynamics questions
- Q1. Which of the following best defines Pharmacokinetics (PK)?
- Q2. Which parameter describes the theoretical volume that a drug would occupy if it were evenly distributed at the same concentration as in plasma?
- Q3. If a drug’s clearance increases while its volume of distribution remains constant, what happens to its elimination half-life (t½)?
- Q4. Which route of drug administration yields 100% bioavailability by definition?
- Q5. Which is most likely when a drug is highly lipophilic and has low plasma protein binding?
- Q6. What does the term Clearance (CL) refer to in pharmacokinetics?
- Q7. What does Pharmacodynamics (PD) study?
- Q8. A drug reaches steady-state concentration after chronic dosing. Approximately how many half-lives are required to reach ~95% of steady-state plasma levels (ass…
- Q9. Which kinetic model is characterized by a constant rate of elimination, independent of drug concentration?
- Q10. Which parameter would most directly determine the loading dose required to rapidly achieve a target plasma concentration?
- Q11. An oral drug undergoes substantial first-pass metabolism in the liver. Which effect does this have on its pharmacokinetics?
- Q12. Which term refers to the fraction of drug unbound to plasma proteins and free to exert effect or be eliminated?
- Q13. If two drugs have equal receptor affinity but one elicits a maximal response while the other elicits only a partial response no matter the dose, how are they c…
- Q14. Which phenomenon describes a decrease in response to a drug over time, requiring higher doses to maintain the same effect?
- Q15. Drug A and Drug B each individually produce 20% reduction in blood pressure. If together they produce 50% reduction, what kind of interaction is this?
- Q16. Which parameter defines the plasma concentration of drug at which 50% of the receptors are occupied (not necessarily producing 50% of maximal effect)?
- Q17. If a drug displays first-order elimination kinetics, what happens to the amount eliminated per unit time as plasma concentration decreases?
- Q18. Which pharmacodynamic parameter refers to the dose at which 50% of the population exhibits a defined therapeutic effect?
- Q19. Which pharmacokinetic concept explains why loading doses are used when a drug has long half-life and slow accumulation to steady state?
- Q20. Which factor would most likely prolong the half-life of a drug in an elderly patient?