Drug Metabolism and Prodrug Strategy Quiz
29 Questions
1 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the purpose of drug metabolism?

  • To convert non-polar drugs into more polar molecules for easier excretion (correct)
  • To decrease the water solubility of drugs
  • To increase the shelf life of drugs
  • To decrease the effectiveness of drugs
  • Which enzymes are particularly involved in adding polar functional groups to drugs?

  • Cytochrome P450 enzymes in the liver (correct)
  • Enzymes in the spleen
  • Enzymes in the lungs
  • Enzymes in the kidneys
  • What class of reactions do phase I reactions fall under in drug metabolism?

  • Reduction, synthesis, and dehydration
  • Hydrolysis, esterification, and polymerization
  • Oxidation, hydration, and condensation
  • Oxidation, reduction, and hydrolysis (correct)
  • Why is it necessary to identify all metabolites of a new drug before approval?

    <p>To determine the structure and stereochemistry of each metabolite</p> Signup and view all the answers

    What happens to polar drugs in the body?

    <p>They are quickly excreted by the kidneys</p> Signup and view all the answers

    How can non-polar drugs be made more water-soluble for excretion?

    <p>By adding polar functional groups through drug metabolism</p> Signup and view all the answers

    What is the significance of understanding species-specific metabolic reactions in in vivo studies?

    <p>It helps determine which test animals are relevant for drug metabolism tests</p> Signup and view all the answers

    What distinguishes regioselective metabolic reactions?

    <p>They differentiate between identical functional groups located in different parts of the molecule</p> Signup and view all the answers

    What characterizes stereoselective metabolic reactions?

    <p>They differentiate between different stereoisomers of chiral molecules</p> Signup and view all the answers

    What is the role of cytochrome P450 enzymes in phase I transformations?

    <p>They catalyze reactions that introduce one oxygen atom into the drug molecule</p> Signup and view all the answers

    How many different families are the cytochrome P450 (CYP) enzymes grouped into?

    <p>4</p> Signup and view all the answers

    How are the subfamilies of cytochrome P450 enzymes designated?

    <p>By a letter</p> Signup and view all the answers

    What type of reaction can cytochrome P450 enzymes catalyze in addition to oxidative reactions?

    <p>Reductions</p> Signup and view all the answers

    Which enzymes catalyze the hydrolysis of amides and esters respectively?

    <p>Esterases and peptidases</p> Signup and view all the answers

    Why do amides tend to be hydrolyzed more slowly than esters?

    <p>Presence of electron-withdrawing groups</p> Signup and view all the answers

    What effect do electron-withdrawing groups have on the susceptibility of amides and esters to hydrolysis?

    <p>Increase susceptibility</p> Signup and view all the answers

    What can happen to drugs during metabolism in terms of the number of metabolic reactions and resulting metabolites?

    <p>Two or more metabolic reactions may occur, resulting in different metabolites</p> Signup and view all the answers

    What type of metabolite is formed when hydroxylation occurs on carbon atoms alpha to a heteroatom?

    <p>Unstable metabolite that is immediately hydrolysed</p> Signup and view all the answers

    Why are tertiary amines more reactive to oxidative dealkylation compared to secondary amines?

    <p>Due to their greater basicity</p> Signup and view all the answers

    What enzyme deactivates the reactive epoxide formed from the oxidation of alkenes?

    <p>Epoxide hydrolase</p> Signup and view all the answers

    What is the fate of the epoxide when it evades the enzyme and acts as an alkylating agent?

    <p>React with nucleophilic groups in proteins or nucleic acids</p> Signup and view all the answers

    What is the intermediate formed when oxidation of an aromatic ring occurs?

    <p>Reactive epoxide</p> Signup and view all the answers

    What normally forms at the para position when an aromatic ring undergoes rearrangement involving a hydride transfer?

    <p>Phenol</p> Signup and view all the answers

    What enzyme can deactivate epoxide to form a diol?

    <p>Glutathione S-transferase</p> Signup and view all the answers

    What happens if the epoxide intermediate evades cytochrome P450 enzymes?

    <p>It acts as an alkylating agent and proves toxic</p> Signup and view all the answers

    Which functional group can be oxidized to hydroxylamides?

    <p>Primary and secondary amides</p> Signup and view all the answers

    What process is related to the toxicity of aromatic amines due to the formation of highly electrophilic intermediates?

    <p>Oxidation of nitrogen atom</p> Signup and view all the answers

    What can aromatic primary amines be methylated into during phase II reaction?

    <p>Secondary amines</p> Signup and view all the answers

    Which enzyme catalyzes the oxidation of sulfur atom converting thiols into disulphides?

    <p>Cytochrome P450 enzymes</p> Signup and view all the answers

    Study Notes

    Drug Metabolism Purpose and Processes

    • Drug metabolism transforms lipophilic compounds into hydrophilic forms for easier excretion.
    • Phase I metabolism primarily involves adding polar functional groups to increase solubility.

    Enzymatic Involvement

    • Cytochrome P450 enzymes (CYP) play a crucial role in introducing polar groups during phase I reactions.
    • CYP enzymes are categorized into multiple families, each consisting of distinct enzymes.

    Phase I Reactions

    • Phase I reactions involve oxidation, reduction, and hydrolysis, altering the chemical structure of drugs.
    • Identification of all drug metabolites before approval is essential for assessing safety and efficacy.

    Drug Behavior in the Body

    • Polar drugs are more readily excreted via urine due to higher solubility.
    • Non-polar drugs can be made more water-soluble through chemical modifications like oxidation or conjugation.

    Species-Specific Metabolism

    • Understanding species-specific metabolic reactions is critical for accurate in vivo study outcomes and safety evaluations.

    Metabolic Reaction Characteristics

    • Regioselective metabolic reactions involve specific metabolic sites on a compound.
    • Stereoselective metabolic reactions favor the transformation of one stereoisomer over another.

    Cytochrome P450 Role

    • Cytochrome P450 enzymes facilitate a range of reactions, predominantly oxidative transformations.
    • They also catalyze other reactions, including dealkylation and hydroxylation.

    Families and Designation

    • Cytochrome P450 enzymes are grouped into over 18 families based on amino acid similarity.
    • Subfamilies are designated with letters to distinguish differences within each family.

    Hydrolysis and Reaction Rates

    • Amides are hydrolyzed more slowly than esters due to their stability and stronger bonding.
    • Electron-withdrawing groups enhance the susceptibility of amides and esters to hydrolysis.

    Metabolic Outcomes

    • Drugs may undergo multiple metabolic reactions, leading to a variety of metabolites.
    • Hydroxylation typically yields metabolites at carbon atoms adjacent to heteroatoms.

    Reactivity of Amine Types

    • Tertiary amines are more prone to oxidative dealkylation than secondary amines due to structural factors.

    Enzymatic Deactivation

    • Epoxides are deactivated by enzymes such as epoxide hydrolase, forming less reactive diols.
    • If epoxide intermediates evade enzymatic deactivation, they can act as alkylating agents.

    Aromatic Ring Metabolism

    • Oxidation of aromatic rings often results in the formation of reactive intermediates, including radical cations.
    • Rearrangement leads to hydroxymethyl derivatives typically forming at the para position.

    Further Transformations

    • Hydroxylamines can be produced from the oxidation of amines.
    • Phase II reactions can methylate aromatic primary amines to form less toxic derivatives.

    Sulfur Oxidation

    • Thiol groups are oxidized to disulphides by specific oxidizing enzymes, impacting drug activity and toxicity profiles.

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Description

    Test your knowledge on drug metabolism and the prodrug strategy used to activate drugs in the body. Learn about the requirements for identifying metabolites of new drugs, determining their structure and stereochemistry, and testing for biological activity.

    More Like This

    Drug Metabolism
    5 questions

    Drug Metabolism

    DistinctiveSloth avatar
    DistinctiveSloth
    Drug Metabolism
    19 questions

    Drug Metabolism

    SustainableSnake avatar
    SustainableSnake
    Pharmacy Prodrugs Quiz
    40 questions

    Pharmacy Prodrugs Quiz

    PolishedQuantum avatar
    PolishedQuantum
    Drug Metabolism Overview
    37 questions

    Drug Metabolism Overview

    HandsomeBixbite136 avatar
    HandsomeBixbite136
    Use Quizgecko on...
    Browser
    Browser