Test your knowledge with the MBPL3621 Introduction to Pharmacology Quiz 1. Essential questions for Year 3 Basic Pharmacology III students. Ace your studies!
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 Answer: A. False Explanation: Receptor antagonists bind to receptors but do not activate them. They block the receptor and prevent agonists from binding, thereby inhibiting a response rather than producing one. --- Question 12 Which of the following are sources for making drugs? Choices: - A. Animals - B. Plants - C. None of the choices - D. Synthetic - E. All the choices Answer: E. All the choices Explanation: Drugs can be derived from multiple sources including animals (e.g., insulin), plants (e.g., morphine), and synthetic/chemical synthesis (e.g., aspirin). Modern pharmaceuticals use all these sources. --- Question 13 Which process affects bioavailability? Choices: - A. Metabolism - B. Distribution - C. Excretion - D. Absorption Answer: D. Absorption Explanation: Bioavailability is primarily determined by absorption and first-pass metabolism. The extent and rate of absorption directly affect how much drug reaches systemic circulation. --- Question 14 Biotransformation of drugs is primarily directed to: Choices: - A. Inactivate the drug - B. Activate the drug - C. Convert non-lipid soluble drugs into lipid soluble metabolites - D. Convert lipid soluble drugs into non-lipid soluble metabolites Answer: D. Convert lipid soluble drugs into non-lipid soluble metabolites Explanation: Biotransformation (metabolism) typically converts lipid-soluble drugs into more water-soluble (non-lipid soluble) metabolites, facilitating their excretion through urine or bile. --- Question 15 The volume of distribution (Vd) relates to: Choices: - A. Single to a daily dose of an administrated drug - B. The amount of drug concentrated in the blood plasma - C. The theoretical volume that contains the total concentration of an administered drug - D. Unchanged drug reaching the systemic circulation - E. An administrated dose to a body weight - F. The amount of a drug in the body to the concentration of a drug calculated - G. The theoretical volume that contains the total amount of an administered drug Answer: G. The theoretical volume that contains the total amount of an administered drug Explanation: Volume of distribution is the theoretical volume necessary to contain the total amount of administered drug at the same concentration observed in blood plasma. It indicates the extent of drug distribution in body tissues. --- Question 16 The reasons determining bioavailability are: Choices: - A. Extent of absorption and hepatic first-pass effect - B. Rheological parameters of blood - C. Glomerular filtration rate - D. Amount of a substance obtained orally and quantity of intakes Answer: A. Extent of absorption and hepatic first-pass effect Explanation: Bioavailability is primarily determined by how much drug is absorbed and how much undergoes first-pass metabolism in the liver before reaching systemic circulation. --- Question 17 All of the following statements about efficacy and potency are true EXCEPT: Choices: - A. The ED50 is a measure of drug's efficacy - B. Efficacy is the maximum effect of a drug - C. Efficacy is usually a more important clinical consideration than potency - D. Potency is a comparative measure, refers to the different doses of two drugs that are needed to produce the same effect Answer: A. The ED50 is a measure of drug's efficacy Explanation: ED50 (effective