Pharmacology Drug Binding Quiz
57 Questions
0 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 most important plasma protein for drug binding?

  • Globulin
  • Fibrinogen
  • Lipoprotein
  • Albumin (correct)
  • What primary factor does drug binding degree depend on?

  • Number of binding sites on proteins (correct)
  • Molecular weight of the drug
  • Concentration of the drug
  • pH of the blood
  • Which patients would likely experience the greatest alterations in drug binding?

  • Patients with hypertension
  • Patients undergoing chemotherapy
  • Patients with diabetes
  • Patients with liver cirrhosis (correct)
  • Drugs absorbed by the gastrointestinal tract must first pass through which organ?

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

    What is the term for the effect that occurs when drugs first pass through the liver?

    <p>First-pass metabolism</p> Signup and view all the answers

    How does drug concentration influence diffusion across a membrane?

    <p>Directly proportional</p> Signup and view all the answers

    Which of the following factors does NOT affect drug diffusion across a membrane?

    <p>Patient's age</p> Signup and view all the answers

    What is the primary mechanism by which drugs cross cell membranes?

    <p>Passive diffusion</p> Signup and view all the answers

    What is the significance of chiral drugs in pharmacology?

    <p>They can have different effects based on their stereochemistry.</p> Signup and view all the answers

    In pharmacokinetics, what does the term 'volume of distribution' refer to?

    <p>The theoretical volume that would contain all of the drug in the bloodstream.</p> Signup and view all the answers

    What role do receptor modulators play in pharmacology?

    <p>They can enhance or inhibit receptor activity depending on their type.</p> Signup and view all the answers

    Which parenteral route allows for sustained dose release and avoids the GI tract?

    <p>Intramuscular injection</p> Signup and view all the answers

    What determines the half-life of a drug in the body?

    <p>The rate at which the drug is metabolized and eliminated.</p> Signup and view all the answers

    Which mechanism is responsible for the movement of drugs from an area of low concentration to high concentration?

    <p>Active transport</p> Signup and view all the answers

    Which statement correctly describes renal clearance?

    <p>It is a measure of the volume of plasma cleared of drug per time unit.</p> Signup and view all the answers

    What type of drug absorption is characterized by complete absorption?

    <p>Intravenous drugs</p> Signup and view all the answers

    Which route is commonly used for drug delivery in general anesthesia?

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

    Which form of a drug is typically pharmacologically active?

    <p>Nonionized form</p> Signup and view all the answers

    In which scenario would you expect vasoconstrictors to be administrated?

    <p>To enhance absorption and reduce area of action in parenteral routes</p> Signup and view all the answers

    What is the primary transport mechanism that does not require energy?

    <p>Facilitated diffusion</p> Signup and view all the answers

    Which parenteral route is often used for patients who do not have IV access?

    <p>Intramuscular route</p> Signup and view all the answers

    What is the primary focus of pharmacokinetics?

    <p>Study of what the body does to a drug</p> Signup and view all the answers

    Which of the following components is NOT part of pharmacokinetics?

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

    What is first-pass elimination?

    <p>The process where drugs are metabolized in the liver before reaching systemic circulation</p> Signup and view all the answers

    Why is the study of drug distribution important in pharmacokinetics?

    <p>It influences the drug's therapeutic and toxic effects</p> Signup and view all the answers

    Which term describes the specific area where a drug interacts with its receptor for clinical effect?

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

    What can impact the pharmacokinetic process of a drug?

    <p>The age of the patient</p> Signup and view all the answers

    What advantage does an intravenous route provide in pharmacokinetics?

    <p>It allows rapid distribution into circulation</p> Signup and view all the answers

    What is the significance of studying pharmacodynamics in contrast to pharmacokinetics?

    <p>Pharmacodynamics relates to the molecular mechanisms of drug action</p> Signup and view all the answers

    Which process primarily removes drugs from the plasma?

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

    What is directly related to the clearance of a drug?

    <p>Organ blood flow</p> Signup and view all the answers

    A high hepatic extraction ratio indicates that a drug is which of the following?

    <p>Flow-limited in its metabolism</p> Signup and view all the answers

    Which route of elimination is primarily considered when referring to organ-independent elimination?

    <p>Breast milk secretion</p> Signup and view all the answers

    What factor does NOT influence renal elimination of a drug?

    <p>Metabolic rate of the liver</p> Signup and view all the answers

    What happens to drugs in acidic urine?

    <p>Reabsorption of acidic drugs occurs</p> Signup and view all the answers

    Which factor typically increases half-life of a drug?

    <p>Decreased renal blood flow</p> Signup and view all the answers

    What is true regarding drug clearance and half-life?

    <p>Clearance is inversely related to half-life</p> Signup and view all the answers

    Which drug type is likely to undergo significant first-pass metabolism?

    <p>High extraction ratio drugs</p> Signup and view all the answers

    What effect does renal insufficiency have on drug metabolism?

    <p>It can increase the risk of toxicity</p> Signup and view all the answers

    The term 'clearance' refers specifically to which of the following?

    <p>Volume of plasma cleared of drug over time</p> Signup and view all the answers

    What describes drugs with a low hepatic extraction ratio?

    <p>Highly dependent on liver blood flow</p> Signup and view all the answers

    What is the primary determinant for renal excretion of drugs?

    <p>Drug molecule's characteristics</p> Signup and view all the answers

    In which condition would the elimination of a drug likely be highest?

    <p>High hepatic extraction ratio</p> Signup and view all the answers

    What is the theoretical definition of the Volume of Distribution (Vd)?

    <p>The volume necessary to hold the same concentration of drug in plasma and interstitial fluid</p> Signup and view all the answers

    When is a larger Volume of Distribution (Vd) likely to be required?

    <p>When a higher loading dose is needed to achieve desired plasma concentration</p> Signup and view all the answers

    Which patient characteristic can significantly influence Volume of Distribution (Vd)?

    <p>Liver disease</p> Signup and view all the answers

    If a drug has a Volume of Distribution (Vd) that exceeds total body water, what can be inferred?

    <p>The drug has high protein binding</p> Signup and view all the answers

    What effect does an increasing Volume of Distribution (Vd) have on plasma drug concentration?

    <p>It decreases the plasma concentration</p> Signup and view all the answers

    Which of the following drugs is associated with a Volume of Distribution (Vd) less than total body water?

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

    In a two-compartment model, the central compartment includes which of the following organs?

    <p>Liver and kidneys</p> Signup and view all the answers

    What is the effect of bolus dosing in relation to Volume of Distribution (Vd)?

    <p>It ensures immediate equilibration across all compartments</p> Signup and view all the answers

    How does drug elimination impact the Volume of Distribution (Vd)?

    <p>It leads to decreased concentrations in plasma</p> Signup and view all the answers

    How does protein binding affect the Volume of Distribution (Vd) of a drug?

    <p>Increased protein binding reduces Vd</p> Signup and view all the answers

    What constitutes a target controlled infusion in drug administration?

    <p>Dosing based on plasma and effect site algorithms</p> Signup and view all the answers

    Which of these factors affects the distribution of drugs within the compartments?

    <p>Drug's molecular size and ionization</p> Signup and view all the answers

    In which scenario would volume of distribution (Vd) approximately double?

    <p>In burn patients</p> Signup and view all the answers

    What is one of the main assumptions made when considering Volume of Distribution (Vd)?

    <p>Drugs distribute and equilibrate instantly across all compartments</p> Signup and view all the answers

    Study Notes

    Introduction to Pharmacology: PharmacoKinetics

    • Pharmacology aims to prevent, cure, and control disease.
    • Anesthesia involves responses to physiological changes, using sedation, general anesthesia, and amnesia. Analgesia, muscle relaxation, and prevention of complications are also important.
    • Safety is crucial in pharmacology.
    • PharmacoKinetics studies how the body affects a drug. Dose and plasma concentrations are related here. Factors impacting this include absorption, distribution, metabolism, and elimination.
    • PharmacoDynamics studies how a drug affects the body. The relationship between effect site concentration and clinical effects is central here.
    • PharmacoBioPhasics focuses on specific areas/effects where drug/receptor engagement creates a clinical effect.

    PharmacoKinetics

    • Absorption is the transfer of a drug from the administration site into the bloodstream.
    • Absorption rate and efficacy depend on the route of administration. Oral intake, injection, inhalation, and topical/transdermal routes are discussed.
    • Distribution is the movement of a drug from the plasma into tissues/cells.
    • Influencing factors include blood flow to tissues, capillary permeability, and drug structure.
    • Molecular size influences how easily drugs cross cell barriers. Smaller molecules typically cross easier.
    • Protein binding affects drug distribution.
    • Binding to albumin is important.

    Factors Affecting Drug Absorption

    • Routes of administration: Intramuscular, inhaled, subcutaneous, intravenous, oral, buccal, rectal.
    • Blood flow to absorption sites: Heat increases absorption; vasoconstriction decreases it.
    • Drug solubility: High lipid solubility (lipophilic) drugs absorb faster.
    • Surface area of the absorption site plays a role in absorption rate.

    Distribution

    • Distribution is the process by which a drug leaves the administration site and enters the plasma and cells.

    • Influencing Factors:

      • Blood flow to tissues
      • Capillary permeability
      • Drug structure
    • Molecular size influences distribution.

    • Active transport requires energy, whereas passive transport follows concentration gradients. This affects drug transfer speed.

    Protein Binding

    • Drugs bind to plasma proteins, often albumin.
    • Bound drug is "trapped" in plasma; free drug enters tissues.
    • Protein binding affects a drug's distribution and elimination.

    Compartments

    • Body water compartments are key for understanding drug distribution.
    • The following are included:
      • total body water
      • intracellular fluid
      • extracellular fluid
        • interstitial fluid
        • plasma
    • A 70 kg person has approximately 42L total body water; intracellular, extracellular compartments are explained.

    Volume of Distribution (Vd)

    • Theoretical volume necessary to contain the same concentration of unbound drug in plasma & interstitial fluid
    • Larger Vd suggests more drug in tissues compared to plasma.
    • Vd is calculated using: Loading dose = Vd x Desired Plasma Concentration.

    Metabolism

    • Metabolism is the process altering drug structure to make it easier to eliminate, by turning it into a polar/water-soluble form.
    • Sites include liver, plasma, kidneys, lungs, and gastrointestinal tract.
    • Enzymes are important in this process.
    • Metabolism can create active metabolites or inactive products
    • Includes oxidation, reduction, and hydrolysis processes.
    • The first phase often converts the compound to a more polar form increasing hydrophilicity (water-soluble).
    • The second (conjugation) phase adds a polar group to the modified molecule

    Elimination

    • Elimination is the irreversible removal of drugs from the body.
    • Routes include:
      • Kidneys (urine)
      • Liver (bile into feces)
      • Lungs (exhalation)
      • Other (sweat, saliva)

    Clearance

    • Removal of drug from plasma over time.
    • Directly related to organ blood flow, fraction of removed drug and dose.
    • Inversely related to the half-life, drug concentration in central compartment.

    Hepatic Extraction Ratio

    • Comparison of arterial versus venous concentration of a drug reflecting the efficiency of liver extraction.
    • "High extraction ratio" suggests a drug extraction and clearance that is flow dependent.
      • Propofol, ketamine, lidocaine, bupivacaine, fentanyl, morphine, metoprolol, nitroglycerin (are all examples of high extraction ratio drugs)
    • "Low extraction ratio" suggests a drug extraction and clearance that is capacity-dependent
      • Rocuronium, lorazepam, methadone, thiopental, warfarin, phenytoin (are all examples of low extraction ratio drugs)

    Renal Elimination & Excretion

    • Renal processes for drug removal
      • Glomerular filtration - process
      • Proximal tubular secretion - process of actively transporting drugs into tubular filtrate
      • Distal tubular reabsorption - process whereby unionized drug potentially passively returns to the bloodstream

    Half-Life (t1/2)

    • Time for the plasma concentration of a drug to decrease by approximately 50%.
    • Factors influencing half-life:
      • Volume of distribution
      • Clearance

    Kinetics of Metabolism

    • Zero-order kinetics: Constant amount of drug metabolized per unit time.
      • Alcohol, aspirin
    • First-order kinetics: Constant fraction metabolized per unit time.
      • Most anesthetics

    Steady State

    • Steady state reached when the rate of drug administration equals the rate of drug elimination.
    • Takes approximately 4-5 half-lives to reach.

    Injection and Infusion Kinetics

    • Injection and infusion kinetics describe drug movement and/or elimination from body.
      • Important variables include:
        • Distribution
        • Redistribution
        • Metabolism
        • Excretion
    • One or multi-compartment models demonstrate how drug distributes in the body.

    Multi-Compartment Models

    • Two- and three-compartment models demonstrate more complex drug distribution in the body.
    • Drug movement between different compartments is dependent upon factors such as:
      • Volume of Distribution
      • Plasma and tissue concentration
      • Rate constants (k)

    Studying That Suits You

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

    Quiz Team

    Related Documents

    Description

    Test your knowledge on the important aspects of drug binding in pharmacology. This quiz covers key concepts such as plasma proteins, drug absorption, and the effects of the liver on drugs. Challenge yourself with questions about how drugs interact with membranes and factors affecting drug diffusion.

    More Like This

    7 Medicines and Pharmacology
    30 questions

    7 Medicines and Pharmacology

    ExcitedChalcedony7132 avatar
    ExcitedChalcedony7132
    Pharmacology: Drug Binding and Action
    5 questions
    Pharmacology Quiz on Drug Binding
    37 questions
    Use Quizgecko on...
    Browser
    Browser