MBPL3621 Introduction to Pharmacology Quiz 1

**Sep/Dec 2022/23** --- ## Question 1 **Which process involves the transfer of a drug from its site of administration to the blood stream?** **Choices:** - A. Absorption - B. Metabolism - C. Excretion - D. Distribution **Answer:** A. Absorption **Explanation:** Absorption is the movement of a drug from its site of administration into the bloodstream. This process is essential for the drug to reach systemic circulation and eventually its site of action. --- ## Question 2 **Receptor agonists result in a drug response.** **Choices:** - A. True - B. False **Answer:** A. True **Explanation:** Receptor agonists bind to receptors and activate them, producing a biological response. This is the mechanism by which many drugs exert their therapeutic effects. --- ## Question 3 **Glomerular filtration of a drug is affected by its:** **Choices:** - A. Rate of tubular secretion - B. Plasma protein binding - C. Lipid solubility - D. Degree of ionization **Answer:** B. Plasma protein binding **Explanation:** Only free (unbound) drug molecules can be filtered through the glomerulus. Drugs bound to plasma proteins are too large to pass through the glomerular membrane, so plasma protein binding directly affects glomerular filtration. --- ## Question 4 **For the calculation of the volume of distribution (Vd) one must take into account:** **Choices:** - A. Therapeutic window of the drug - B. Concentration of a substance in plasma - C. The dose of the drug - D. Concentration of substance in urine **Answer:** B. Concentration of a substance in plasma **Explanation:** Volume of distribution (Vd) is calculated using the formula: Vd = Dose / Plasma concentration. It represents the theoretical volume needed to contain the total amount of drug at the same concentration as in plasma. --- ## Question 5 **This illustration below is concerned with which factor that influences the response to drug therapy.** **Choices:** - A. Patient compliance - B. Rate of metabolism and excretion - C. Drug-receptor interaction - D. Placebo effects **Answer:** B. Rate of metabolism and excretion **Explanation:** The illustration focuses on pharmacokinetics (how the body processes the drug), not pharmacodynamics (drug effects). Metabolism and excretion are pharmacokinetic processes that determine drug concentration over time. --- ## Question 6 **Increasing the dose of the drug will increase the strength of the bond the drug has with its receptor. As a result, the response will increase.** **Choices:** - A. False - B. True **Answer:** A. False **Explanation:** Increasing the dose does not change the strength of drug-receptor binding (affinity). Instead, it increases the number of receptors occupied, which may increase the response up to a maximum effect (efficacy). --- ## Question 7 **The strength of the drug is related to the dose of the drug.** **Choices:** - A. True - B. False **Answer:** A. True **Explanation:** Strength refers to the amount of drug in a dosage form (e.g., 500 mg tablet). Higher doses contain more drug and therefore have greater strength, though this is different from potency, which is a comparative measure. --- ## Question 8 **What does "pharmacokinetics" include?** **Choices:** - A. Influence of drugs on metabolism processes - B. Drug biotransformation in the organism - C. Complications of drug therapy - D. Influence of drugs on genes **Answer:** B. Drug biotransformation in the organism **Explanation:** Pharmacokinetics describes what the body does to the drug, including absorption, distribution, metabolism (biotransformation), and excretion (ADME). --- ## Question 9 **Drugs which undergo high degree of first-pass metabolism in liver:** **Choices:** - A. Are contraindicated in liver disease - B. Go through elimination - C. Have low oral bioavailability - D. Are excreted primarily in bile **Answer:** C. Have low oral bioavailability **Explanation:** First-pass metabolism occurs when orally administered drugs are metabolized in the liver before reaching systemic circulation, reducing the amount of active drug available and thus decreasing oral bioavailability. --- ## Question 10 **Bioavailability of drug refers to:** **Choices:** - A. All the choices - B. Ratio of drug excreted unchanged in urine to that excreted as metabolites - C. None of the choices - D. Ratio of orally administered drug to that excreted in the faeces - E. Percentage of administered dose that reaches systemic circulation in the changed form - F. Ratio of oral dose to parenteral dose **Answer:** C. None of the choices **Explanation:** Bioavailability is the percentage of administered dose that reaches systemic circulation in the UNCHANGED (active) form, not "changed form" as stated in option E. None of the provided options correctly defines bioavailability. --- ## Question 11 **Receptor antagonists result in a drug response.** **Choices:** - A. False - B. True *