ANTIMYCOBACTERIAL DRUGS
48 Questions
2 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 one of the problems in treating Mycobacteria SPP mentioned in the text?

  • Fast growth rate
  • High permeability due to a thin cell wall
  • Dormant state in the body for a short period (correct)
  • Treatable with only one drug

    • Why are first-line agents always used in combination for treating Mycobacteria SPP?

  • To speed up the treatment process
  • To prevent the development of resistance (correct)
  • Because single-drug treatment is more effective
  • To reduce the cost of medication

    • What characteristic of the cell wall of Mycobacteria SPP makes it difficult for drugs to enter?

  • Thin structure
  • High permeability
  • Lipid-rich composition (correct)
  • Protein-rich composition

    • How long does it typically take for symptoms to develop after Mycobacteria SPP enters the body?

    <p>2-3 months</p> Signup and view all the answers

    When are second-line agents used in treating Mycobacteria SPP?

    <p>When first-line agents have failed</p> Signup and view all the answers

    How many drugs are typically given during the initial intensive phase of tuberculosis treatment?

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

    Which drug allows the total duration of therapy for tuberculosis to be reduced to 6 months without loss of efficacy?

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

    What is the mechanism of action of Isoniazid against Mycobacterium tuberculosis?

    <p>Inhibits mycolic acid synthesis</p> Signup and view all the answers

    Which enzyme activates Isoniazid within Mycobacterium tuberculosis cells?

    <p>Catalase-peroxidase (KatG)</p> Signup and view all the answers

    When is the continuation phase of tuberculosis treatment initiated?

    <p>After 2 months of treatment</p> Signup and view all the answers

    What is the main reason to extend tuberculosis treatment for an additional 4 months in some cases?

    <p>If Mycobacterium is still present</p> Signup and view all the answers

    What is the recommended daily dosage of Isoniazid for treatment of latent tuberculosis?

    <p>300 mg/d</p> Signup and view all the answers

    Which enzyme is responsible for metabolizing Isoniazid in the liver?

    <p>N-acetyltransferase</p> Signup and view all the answers

    What is a common adverse effect of Isoniazid that can be prevented by supplementing with Pyridoxine?

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

    Which body fluid or tissue has concentrations of Isoniazid ranging from 20% to 100% of simultaneous serum concentrations?

    <p>Central nervous system</p> Signup and view all the answers

    All medications can experience increased concentrations due to the inhibitory effects of Isoniazid on cytochrome P450 enzymes, except?

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

    How does Rifampin exert its bactericidal effect on mycobacteria?

    <p>By inhibiting RNA synthesis</p> Signup and view all the answers

    What is the primary mechanism of resistance to Rifampin?

    <p>Reduced binding of Rifampin to RNA polymerase</p> Signup and view all the answers

    How is Rifampin mainly excreted from the body?

    <p>Through the liver into bile</p> Signup and view all the answers

    What is a characteristic of Rifampin that allows it to kill intracellular organisms?

    <p>It penetrates into phagocytic cells</p> Signup and view all the answers

    How does Rifampin affect the elimination of other drugs in the body?

    <p>It increases the elimination of numerous other drugs by inducing cytochrome P450 isoforms</p> Signup and view all the answers

    What type of organisms is Rifampin active against in vitro?

    <p>Gram-positive organisms, some Gram-negative organisms, Mycobacteria, and Chlamydiae</p> Signup and view all the answers

    What is the mechanism of action of Rifampin in inhibiting bacterial RNA synthesis?

    <p>Binding to the β subunit of RNA polymerase</p> Signup and view all the answers

    Which factor can lead to resistance to Rifampin in bacteria?

    <p>Point mutations in the gene for the α subunit of RNA polymerase</p> Signup and view all the answers

    In what scenario does Rifampin achieve adequate cerebrospinal fluid concentrations?

    <p>Only in the presence of meningeal inflammation</p> Signup and view all the answers

    Which adverse effect is occasionally associated with Rifampin use?

    <p>Cholestatic jaundice</p> Signup and view all the answers

    How does Rifampin impact the metabolism of other drugs in the body?

    <p>It strongly induces most cytochrome P450 isoforms</p> Signup and view all the answers

    For what purpose is Rifampin commonly used as prophylaxis?

    <p>In contacts of children with Haemophilus influenzae type b disease</p> Signup and view all the answers

    What is the primary mechanism of resistance to ethambutol?

    <p>Overexpression of emb gene products</p> Signup and view all the answers

    How does ethambutol affect renal failure patients?

    <p>It accumulates in the body</p> Signup and view all the answers

    What is the most common serious adverse event associated with ethambutol use?

    <p>Retrobulbar neuritis</p> Signup and view all the answers

    When does ethambutol cross the blood-brain barrier?

    <p>When the meninges are inflamed</p> Signup and view all the answers

    In what scenario should ethambutol dosage be reduced to three times weekly?

    <p>If creatinine clearance is less than 30 mL/min</p> Signup and view all the answers

    What is the recommended monitoring schedule for visual acuity and color discrimination in patients taking ethambutol?

    <p>Baseline and monthly monitoring</p> Signup and view all the answers

    What is the active form of Pyrazinamide that exerts its activity against mycobacteria?

    <p>Pyrazinoic acid</p> Signup and view all the answers

    How is Rifampin mainly excreted from the body?

    <p>Through bile</p> Signup and view all the answers

    How does Pyrazinamide exert its activity against mycobacteria?

    <p>By disrupting cell membrane metabolism and transport functions</p> Signup and view all the answers

    What is the main cause of resistance to Pyrazinamide?

    <p>Mutations in pncA</p> Signup and view all the answers

    Where is Pyrazinamide converted to its active form, pyrazinoic acid?

    <p>Within mycobacteria by pyrazinamidase</p> Signup and view all the answers

    What is the primary site of action of Pyrazinamide against mycobacteria?

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

    How is Pyrazinamide primarily absorbed in the body?

    <p>By passive diffusion through cell membranes</p> Signup and view all the answers

    Which combination of drugs is recommended for the initial therapy of lepromatous leprosy?

    <p>Dapsone, Rifampin, Clofazimine</p> Signup and view all the answers

    What is the most widely used drug for leprosy that inhibits folate synthesis?

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

    Which adverse reaction is commonly associated with the use of Dapsone?

    <p>Hemolysis in individuals with G6PD deficiency</p> Signup and view all the answers

    Where is Dapsone predominantly retained in the body?

    <p>Skin, muscle, liver, and kidney</p> Signup and view all the answers

    What is a common metabolic fate of most excreted Dapsone?

    <p>Biliary excretion and intestinal reabsorption</p> Signup and view all the answers

    Which condition is often seen during Dapsone therapy of lepromatous leprosy?

    <p>Erythema nodosum leprosum</p> Signup and view all the answers

    In what scenario might the dose of Dapsone need adjustment?

    <p>Renal failure</p> Signup and view all the answers

    More Like This

    Mycobacteria: General Characteristics
    29 questions

    Quiz on Mycobacterium Characteristics with Flashcards

    AdvantageousMoldavite2711 avatar
    AdvantageousMoldavite2711
    Mycobacteria Classification Flashcards
    12 questions

    Mycobacteria Classification Flashcards

    ProlificRetinalite5738 avatar
    ProlificRetinalite5738
    Mycobacteria and Tuberculosis Quiz
    37 questions

    Mycobacteria and Tuberculosis Quiz

    ConciseAllegory avatar
    ConciseAllegory
    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser