Metabolism PPT No. 3 PDF

METABOLISM - PPT NO. 3 (DR. GUPTA) 1. What is biotransformation? A: It is the process of metabolizing drugs and other substances to make them more polar and excretable. 2. What is the primary purpose of metabolism in pharmacology? A: To detoxify drugs and facilitate their excretion from the body....

METABOLISM - PPT NO. 3 (DR. GUPTA) 1. What is biotransformation? A: It is the process of metabolizing drugs and other substances to make them more polar and excretable. 2. What is the primary purpose of metabolism in pharmacology? A: To detoxify drugs and facilitate their excretion from the body. 3. What are the main sites of drug metabolism? A: Liver, kidneys, lungs, intestine, and blood. 4. What are the two main phases of drug metabolism? A: Phase I (modification) and Phase II (conjugation). 5. Name the primary enzyme family involved in drug metabolism. A: Cytochrome P450 enzymes (CYPs). 6. What is first-pass metabolism? A: The initial metabolism of a drug by the liver before it reaches systemic circulation. 7. What types of reactions occur in Phase I metabolism? A: Oxidation, reduction, and hydrolysis. 8. What types of reactions occur in Phase II metabolism? A: Conjugation reactions such as glucuronidation, sulfation, and acetylation. 9. Why is first-pass metabolism clinically significant? A: It reduces the bioavailability of some orally administered drugs. 10. How can first-pass metabolism be bypassed? A: By administering the drug via intravenous, rectal, or transdermal routes. 11. What is the clinical significance of drug metabolism? A: It affects drug efficacy, toxicity, and the design of dosage regimens. 12. What is an example of a drug affected by first-pass metabolism? A: Propranolol. 13. How do genetics affect drug metabolism? A: Genetic differences can lead to variations in enzyme activity, affecting drug metabolism. 14. What are poor metabolizers? A: Individuals with low enzyme activity leading to slower drug metabolism. 15. What effect does age have on drug metabolism? A: Elderly patients often have decreased hepatic and renal function, affecting drug metabolism and clearance. 16. Name a factor related to diet that can affect drug metabolism. A: Grapefruit juice, which can inhibit CYP3A4. 17. What is a prodrug? A: An inactive drug that is metabolized into an active form in the body. 18. How do Phase I enzymes generally alter a drug molecule? A: By introducing or uncovering polar functional groups. 19. Which enzyme is primarily responsible for metabolizing alcohol? A: Alcohol dehydrogenase (ADH). 20. What is cytochrome P450? A: A family of enzymes that play a key role in drug metabolism. 21. What is the function of Phase II metabolism? A: To increase water solubility of the drug for easier excretion. 22. What are UDP-glucuronosyltransferases (UGTs)? A: Phase II enzymes that add glucuronic acid to drugs, aiding in excretion. 23. What is an enzyme inducer? A: A substance that increases the activity of metabolic enzymes. 24. What is an enzyme inhibitor? A: A substance that decreases the activity of metabolic enzymes. 25. Name a common CYP3A4 inducer. A: Rifampicin. 26. Name a common CYP3A4 inhibitor. A: Ketoconazole. 27. What role does gender play in drug metabolism? A: Males and females may metabolize drugs at different rates due to hormonal differences. 28. How can liver disease affect drug metabolism? A: It can decrease enzyme activity and blood flow, leading to altered drug clearance. 29. What is oxidative deamination? A: A Phase I reaction where an amine group is removed and converted into a ketone or acid. 30. What are flavin-containing monooxygenases (FMOs)? A: Phase I enzymes involved in the oxidation of nitrogen and sulfur-containing compounds. 31. Why is acetaminophen toxic in high doses? A: It produces a toxic metabolite that accumulates when detoxification pathways are overwhelmed. 32. What is the role of monoamine oxidases (MAOs) in metabolism? A: They metabolize neurotransmitters by oxidative deamination. 33. What is a conjugation reaction? A: A Phase II reaction that attaches a polar group to a drug, making it more excretable. 34. Name a drug that undergoes glucuronidation. A: Morphine. 35. What is the significance of drug-food interactions in metabolism? A: They can lead to increased or decreased drug levels, affecting efficacy and toxicity. 36. What does the term “xenobiotic” refer to? A: A foreign substance in the body, such as a drug or environmental toxin. 37. How does smoking affect drug metabolism? A: It can induce certain CYP enzymes, altering drug metabolism. 38. What is hydrolysis in drug metabolism? A: A Phase I reaction that splits esters or amides into acids and alcohols or amines. 39. What is methylation in Phase II metabolism? A: A conjugation reaction that adds a methyl group, often reducing water solubility. 40. What does the CYP enzyme nomenclature indicate? A: Family (CYP), subfamily (letter), and specific isozyme (number). 41. Name a Phase II reaction that increases water solubility. A: Sulfation. 42. Why are drugs dosed based on anticipated metabolism? A: To ensure therapeutic levels and avoid toxicity. 43. What is N-dealkylation? A: A Phase I reaction that removes an alkyl group attached to nitrogen. 44. How can renal disease impact drug metabolism? A: It can affect the excretion of metabolites, leading to toxicity. 45. How does metabolism affect a prodrug? A: Metabolism activates the prodrug into its therapeutic form. 46. What is COMT? A: Catechol-O-methyltransferase, an enzyme involved in neurotransmitter metabolism. 47. What is the primary outcome of Phase I oxidation? A: The addition of hydroxyl groups to increase polarity. 48. How does alcohol consumption affect drug metabolism? A: It induces certain enzymes, which may speed up the metabolism of other drugs. 49. What is glucuronidation? A: The addition of glucuronic acid to a drug, making it more water-soluble. 50. Name a Phase I enzyme other than CYPs. A: Aldehyde dehydrogenase. 51. What is the role of cytochrome P450 3A4 (CYP3A4)? A: It metabolizes a large proportion of drugs in the liver and intestines. 52. How does disease state impact drug metabolism? A: Conditions like liver or kidney disease can slow drug clearance and increase toxicity. 53. What is a nitro reduction reaction? A: A Phase I reduction reaction that reduces nitro groups on drugs. 54. What is a possible effect of enzyme induction? A: Reduced drug effectiveness due to increased metabolism. 55. How does grapefruit juice interact with metabolism? A: It inhibits CYP3A4, increasing blood levels of certain drugs. 56. What are GSTs in Phase II metabolism? A: Glutathione-S-transferases, enzymes that add glutathione to drugs for detoxification. 57. What happens in O-dealkylation? A: An alkyl group is removed from an oxygen atom in the drug structure. 58. What does sulfation do to a drug molecule? A: Adds a sulfate group to increase water solubility. 59. Why is pharmacogenomics important in drug metabolism? A: It helps predict individual responses to drugs based on genetic factors. 60. What is Phase II glycine conjugation? A: The addition of glycine to a drug to increase solubility. 61. What are NATs in Phase II metabolism? A: N-acetyltransferases, which add acetyl groups to drugs. 62. What is the clinical relevance of enzyme inhibition? A: It can lead to drug toxicity due to decreased metabolism. 63. What is N-oxidation in drug metabolism? A: The addition of an oxygen atom to nitrogen in a drug molecule. 64. Why might a higher dose be required for a drug with extensive first-pass metabolism? A: To ensure sufficient levels reach systemic circulation. 65. How does obesity influence drug metabolism? A: It can alter blood flow and enzyme activity, affecting drug clearance. 66. What is O-methylation? A: A Phase II reaction that adds a methyl group to oxygen in the drug molecule. 67. How can environmental factors affect drug metabolism? A: Exposure to pollutants and chemicals can induce or inhibit metabolic enzymes. 68. What is the purpose of a prodrug strategy? A: To improve drug properties such as solubility, permeability, and stability. 69. What is the function of amine oxidases in drug metabolism? A: They metabolize amines, often resulting in deamination. 70. What happens during deamination? A: The removal of an amine group, producing ketones or acids. 71. What is the outcome of Phase II glucuronidation? A: Drugs become more hydrophilic and are readily excreted. 72. Why might dose adjustment be necessary in elderly patients? A: Decreased hepatic and renal function can slow metabolism. 73. What does PAPS provide in sulfation reactions? A: It supplies the sulfate group for conjugation. 74. Why is CYP3A4 inhibition by ketoconazole significant? A: It can increase levels of other drugs metabolized by CYP3A4, risking toxicity. 75. Name a drug interaction type involving enzyme inhibition. A: Drug-food interaction, like grapefruit juice and statins. 76. What is the role of flavin monooxygenase (FMO) enzymes? A: To oxidize nitrogen- and sulfur-containing drugs. 77. How does liver function impact Phase I metabolism? A: Decreased liver function can reduce oxidation and prolong drug action. 78. What does acetylation do in drug metabolism? A: Adds an acetyl group, which can affect drug solubility. 79. How does enzyme induction affect prodrugs? A: It can increase conversion rates, enhancing therapeutic effects. 80. What does conjugation with glutathione achieve? A: Detoxifies reactive drug metabolites to prevent toxicity. 81. What is an azo reduction reaction? A: A reduction of azo groups, commonly seen in some drug metabolites. 82. What is the potential consequence of slow acetylators in drug metabolism? A: They may experience prolonged drug action and increased side effects. 83. What role do lifestyle factors like alcohol play in drug metabolism? A: Alcohol can induce certain enzymes, altering drug clearance rates. 84. What type of reaction is glycine conjugation? A: A Phase II conjugation reaction. 85. What is methylation in drug metabolism? A: A Phase II reaction that can decrease water solubility. 86. How can pregnancy affect drug metabolism? A: Hormonal changes can alter enzyme activity, affecting drug metabolism rates. 87. Why might CYP enzyme inducers require dosage adjustments? A: They increase drug clearance, potentially lowering therapeutic effects. 88. What is the importance of UDP in glucuronidation? A: It provides the glucuronic acid group for conjugation. 89. What is hydroxylation in drug metabolism? A: The addition of a hydroxyl group to increase water solubility. 90. What does the term “Phase I metabolite” refer to? A: A drug molecule altered by oxidation, reduction, or hydrolysis. 91. How does enzyme variability affect drug response? A: Different enzyme activity levels lead to varying rates of drug metabolism among individuals. 92. What is dealkylation in Phase I metabolism? A: The removal of an alkyl group from a molecule. 93. Why are water-soluble metabolites important for excretion? A: They are easily eliminated through the kidneys. 94. What role does CYP2D6 play in drug metabolism? A: It metabolizes many drugs, including antidepressants and opioids. 95. How do enzyme inhibitors affect prodrug activation? A: They can reduce activation, leading to reduced therapeutic effects. 96. What is an example of an oxidation reaction? A: Hydroxylation, where a hydroxyl group is added to the drug. 97. Why might a lipophilic drug undergo extensive metabolism? A: To make it more water-soluble for excretion. 98. How does renal function impact drug excretion? A: Decreased renal function can prolong the presence of metabolites. 99. What is the clinical impact of Phase II methylation? A: It can alter drug activity and reduce solubility. 100. How does pharmacogenetics impact personalized medicine? A: It allows for tailored drug dosing based on individual metabolic capacity.