General Pharmacology

Topics in this chapter

• Basic Definitions and Fundamental Principles
• Absorption, Distribution, and Transporters
• Drug Metabolism and Elimination Pathways
• Pharmacokinetic Formulas and Clearance Kinetics
• Receptor Mechanisms and Agonist Dynamics
• Drug Antagonism and Inverse Agonists

Practice questions

1. Question 1Q-07EBFF

   A 45-year-old man with chronic renal failure is prescribed a drug that is eliminated exclusively by glomerular filtration. If his glomerular filtration rate (GFR) drops to 25% of normal, how should the maintenance dose of this drug be adjusted to maintain the same average steady-state plasma concentration?

   1. A.Decrease the maintenance dose to 25% of the normal dose
   2. B.Decrease the maintenance dose to 50% of the normal dose
   3. C.Increase the dosing interval fourfold while keeping the dose constant
   4. D.Double the maintenance dose and halve the dosing interval
   See the answer and solution
2. Question 2Q-8E2EB1

   Which of the following pharmacokinetic parameters is defined mathematically as the apparent volume in which a drug must be distributed to maintain a concentration equal to that in plasma?

   1. A.Clearance
   2. B.Volume of distribution
   3. C.Bioavailability
   4. D.Elimination half-life
   See the answer and solution
3. Question 3Q-BB1754

   A drug is administered as a continuous intravenous infusion. If the elimination half-life of this drug is 4 hours, approximately how long will it take to reach 90% of its ultimate steady-state plasma concentration?

   1. A.4 hours
   2. B.8 hours
   3. C.13.3 hours
   4. D.20 hours
   See the answer and solution
4. Question 4Q-707409

   A novel competitive antagonist is administered to a patient. Which of the following best describes the effect of a competitive antagonist on the agonist dose-response curve?

   1. A.Downward shift of the curve with a decrease in maximal efficacy
   2. B.Parallel shift of the curve to the right without a change in maximal efficacy
   3. C.Parallel shift of the curve to the left with an increase in potency
   4. D.No change in the curve unless a partial agonist is used
   See the answer and solution
5. Question 5Q-F59646

   Which of the following transporters is primarily responsible for the ATP-dependent efflux of drugs across the blood-brain barrier and intestinal mucosa, often leading to multidrug resistance?

   1. A.Organic anion transporter 1 (OAT1)
   2. B.P-glycoprotein (MDR1 / ABCB1)
   3. C.Glucose transporter 4 (GLUT4)
   4. D.Serotonin transporter (SERT)
   See the answer and solution