Walters -Fluoroquinolones Flashcards Preview

IDIT > Walters -Fluoroquinolones > Flashcards

Flashcards in Walters -Fluoroquinolones Deck (15)
Loading flashcards...
1
Q

What type of antibiotic is Fluroquinolones

A
  1. Cidal

2. G - and G+ bacteria

2
Q

What is the mechanism of action for gram negative bacteria? What about gram + bacteria?

A

Gram negative: inhibits DNA gyrase–> cant replicate DNA bc FQ prevent rejoining of DNA (usually unwinds DNA in bacteria)

Gram positive: inhibits topoisomerase IV (an enzyme involved in sep. replicated DNA strands into daughter cells)

3
Q

What is the distinction between Second generation FQ’s and third generation FQ’s. are less active in strep. _____

A

Second generation FQ’s are LESS active in strep pneumoniae. Third generation FQ’s are MORE reactive and are called Respiratory FQ’s

4
Q

What are the second generation FQs

A
  1. Ciprofloxacin- the best FQ for Gram - activity
  2. Ciloxan -opthalmic
  3. Cipro HC - otic
  4. Ofloxacin
5
Q

What are drug interactions with Cipro?

A
  1. Lowers clearance of theophylline so theophylline levels increase which can cause toxicity
  2. Cipro inhibits CYP3A4 and CYP1A2; increases levels of methadone and tizanidine
6
Q

what does increase level of methadone cause

A

possible respiratory depression

7
Q

what does increase level of tizanidine cause

A

sedation, hypotension, hallucinations

8
Q

What is the only third generation FQ that is an opthalmic (not respiratory) product

A

Gatifloxacin

9
Q

What are the third generation FQs?

A
  1. Gemifloxacin
  2. Levofloxacin (isomer of Oflaxacin)
  3. Moxifloxacin: can prolong QT interval in healthy patients
10
Q

What is side affect of levofloxacin

A

risk of prolonging Q-T interval in elderly; FDA says there is acute hepatitis and fatal events

11
Q

What is a fourth generation FQ?

A

Besifloxacin: for bacterial conjunctivitis due to susceptible organisms.

12
Q

What are side effects of Fluoroquinolones

A
  1. phototoxicity: burning, redness, swelling, blisters, rash, and itch
  2. arthropathy: damages growing cartilage; Dont use in prepubertal children or if pregnant!
  3. Tendon rupture: BBW! over 65 or on steroids; it can occur weeks/months after you discontinue drug
  4. Changes in blood sugar; impt for diabetics
  5. CNS stimulation; convulsions, anxiety
  6. Naseua, vomiting, diarrhea
  7. peripheral neuropathy
  8. psudomembranous colitis from C. difficile
13
Q

What is C. difficile? what does it cause

A

can be part of our normal flora, but in presence of Antibiotics it can form a spore to protect itself from antibiotic. Then can reemerge when Ab is gone and can grow without competition for nutrients and can generate 2 exotoxins that can cause intestinal fluid secretion, mucosal injury, inflammation, and bloody diarrhea. A plaque forms that looks like a membrane on the colon mucosa called a pseudomembrane

14
Q

how do you treat pseudomembranous colitis

A

Fidaxomicin; CIDAL -inhibits RNA polymerase. This and its metabolite have significant post antibiotic activity which might contribute to its CIDAL effect. Side effects include naseua, vomiting, GI hemorrage, anemia and neutropenia.

15
Q

what are drug interactions with FQ

A

avoid antacids, and iron supplements bc these drugs can chelate with mono and divalent cations thus decreasing absorption of antibiotic.