Quinolones and Fluoroquinolones
12 Questions
20 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

Which of the following bacteria are resistant to ciprofloxacin?

  • E. coli, Klebsiella, and Salmonella
  • Bacteroides fragilis, Clostridium difficile, and most anaerobes (correct)
  • Staphylococcus aureus, Pseudomonas aeruginosa, and Mycobacterium tuberculosis
  • Vibrio cholerae and Campylobacter jejuni

    • Which of the following routes of administration is NOT mentioned for ciprofloxacin?

  • Topical
  • Intramuscular (correct)
  • Oral
  • Intravenous

    • Which of the following adverse effects of ciprofloxacin is NOT mentioned in the text?

  • Headache, dizziness, insomnia, and confusion
  • Muscle weakness and fatigue (correct)
  • Nausea, vomiting, and abdominal discomfort
  • Skin rashes, urticaria, and eosinophilia

    • Which newer fluoroquinolone has greater activity against streptococci and some activity against anaerobes?

    <p>Moxifloxacin (D)</p> Signup and view all the answers

    Which of the following is NOT mentioned as a bacterium susceptible to ciprofloxacin?

    <p>Acinetobacter baumannii (B)</p> Signup and view all the answers

    Which of the following drug interactions with ciprofloxacin is NOT mentioned in the text?

    <p>Increased plasma concentration of theophylline (B)</p> Signup and view all the answers

    What is the mechanism of action of nalidixic acid?

    <p>Inhibition of DNA gyrase enzyme in gram-negative bacteria (C)</p> Signup and view all the answers

    Which bacteria is nalidixic acid NOT effective against?

    <p>Pseudomonas (B)</p> Signup and view all the answers

    What is the main adverse effect associated with fluoroquinolones?

    <p>Central nervous system (CNS) effects (C)</p> Signup and view all the answers

    What is the mechanism of action of fluoroquinolones?

    <p>Inhibition of DNA gyrase enzyme in gram-negative bacteria (B)</p> Signup and view all the answers

    Which of the following is a second-generation fluoroquinolone?

    <p>Ofloxacin (B)</p> Signup and view all the answers

    What is the antibacterial spectrum of ciprofloxacin?

    <p>Highly effective against aerobic gram-negative organisms (C)</p> Signup and view all the answers

    Flashcards

    What do quinolones and fluoroquinolones do?

    A group of antibiotics that target and inhibit bacterial DNA synthesis, leading to bacterial cell death.

    What is Nalidixic acid?

    A first-generation quinolone that inhibits DNA gyrase, an enzyme crucial for bacterial DNA replication, and is specifically effective against certain gram-negative bacteria.

    What are fluoroquinolones?

    A class of antibiotics like Ciprofloxacin targeting both DNA gyrase and topoisomerase IV, inhibiting bacterial DNA replication and killing bacteria (bactericidal).

    What is a key characteristic of Ciprofloxacin?

    It's a broad-spectrum antibiotic effective against a wide range of gram-negative bacteria including E. coli, Enterobacter, Proteus, Klebsiella, Salmonella, Shigella, and others.

    Signup and view all the flashcards

    How does Ciprofloxacin travel through the body?

    It's absorbed from the gut, widely distributed in the body, and excreted primarily via urine.

    Signup and view all the flashcards

    What are the main side-effects of fluoroquinolones?

    Common side-effects are related to the digestive system, nervous system, and skin, including nausea, vomiting, headaches, dizziness, and rashes.

    Signup and view all the flashcards

    What are important contraindications and precautions for fluoroquinolones?

    Avoid use during pregnancy due to safety concerns. It's also not recommended for young children because of potential cartilage damage.

    Signup and view all the flashcards

    How can fluoroquinolones affect other drugs?

    They can increase the levels of certain medications like theophylline and warfarin in the blood by inhibiting their metabolism in the liver.

    Signup and view all the flashcards

    What is nalidixic acid used for?

    It's a commonly prescribed quinolone for uncomplicated urinary tract infections (UTIs) due to its effectiveness against gram-negative bacteria.

    Signup and view all the flashcards

    What else is nalidixic acid effective against?

    It's also useful in treating diarrhea caused by certain bacteria, such as Salmonella and Shigella.

    Signup and view all the flashcards

    What is a serious potential side effect of fluoroquinolones?

    It can cause tendon inflammation and even rupture, especially in athletes, as it can affect tendon health.

    Signup and view all the flashcards

    What is a specific concern with Moxifloxacin?

    A specific fluoroquinolone called moxifloxacin can potentially prolong the QT interval, which is a measurement of heart rhythm.

    Signup and view all the flashcards

    Study Notes

    Quinolones and Fluoroquinolones

    • The first quinolone, nalidixic acid, is a urinary antiseptic effective against gram-negative bacteria including E. coli, Proteus, Klebsiella, Enterobacter, Salmonella, and Shigella, but not Pseudomonas.
    • Nalidixic acid inhibits DNA gyrase enzyme and interferes with the replication of bacterial DNA.
    • It is useful in the treatment of uncomplicated UTI due to gram-negative bacteria and diarrhea due to Shigella or Salmonella.

    Mechanism of Action

    • Fluoroquinolones (FQs) inhibit bacterial DNA synthesis (bactericidal) by inhibiting DNA gyrase in gram-negative bacteria and topoisomerase IV in gram-positive bacteria.

    Antibacterial Spectrum

    • Ciprofloxacin is the prototype drug and is highly effective against aerobic gram-negative organisms:
    • E. coli
    • Coli
    • Enterobacter
    • Proteus
    • Klebsiella
    • Salmonella
    • Shigella
    • H. ducreyi
    • H. influenzae
    • N. gonorrhoeae
    • N. meningitidis
    • V. cholerae
    • Campylobacter jejuni
    • Ciprofloxacin also has activity against S. aureus, Pseudomonas aeruginosa, and M. tuberculosis.

    Pharmacokinetics

    • Ciprofloxacin is administered by oral, i.v., or topical routes.
    • It is well absorbed from the gut, but food delays its absorption.
    • It is widely distributed in the body and reaches high concentration in kidney, lung, prostatic tissue, bile, macrophages, etc.
    • It is excreted mainly in urine.

    Adverse Effects

    • Common adverse effects are related to the Gl tract (nausea, vomiting, abdominal discomfort), CNS (headache, dizziness, insomnia, confusion, hallucinations, convulsions), and skin (rashes, urticaria, itching, eosinophilia, photosensitivity).
    • Tenosynovitis and tendon rupture can occur, especially in athletes.
    • Moxifloxacin can cause prolongation of QT interval.

    Contraindications and Precautions

    • FQs are contraindicated in pregnancy.
    • FQs should be avoided in young children due to the risk of cartilage damage.

    Drug Interactions

    • Ciprofloxacin increases the plasma concentration of theophylline, warfarin, etc., by inhibiting their metabolism.
    • Nonsteroidal anti-inflammatory drugs (NSAIDs) may potentiate CNS side effects of FQs (confusion, irritability, and rarely convulsions).
    • Absorption of FQs is reduced by antacids, ferrous salts, and sucralfate.

    Studying That Suits You

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

    Quiz Team

    Description

    Test your knowledge about the first quinolone, nalidixic acid, its mechanism of action, and its effectiveness against various gram-negative bacteria including E.coli, Proteus, and Klebsiella.

    More Like This

    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser