C14

Question 1

what about Quinolones?

Answer 1

• member of broad-spectrum bacteriocidals
• bicyclic core structure related to the substance 4-quinolone
• Nearly all quinolones in use are fluoroquinolones (contain a fluorine)

Question 2

name Fluoroquinolones

Answer 2

• Moxifloxacin
• Levofloxacin
• Ofloxacin
• Norfloxacin

Question 3

1stG Fluoroquinolone

Answer 3

Norfloxacin

does NOT achieve adequate plasma levels for use in most systemic infections

Question 4

Norfloxacin spectrum?

Answer 4

the common pathogens that cause urinary tract infections

Question 5

2ndG Fluoroquinolone?

Answer 5

Ciprofloxacin and ofloxacin

Question 6

Ciprofloxacin and ofloxacin spectrum?

Answer 6

• G-‘s
• gonococcus
• G-‘s cocci
• mycobacteria
• Mycoplasma pneumoniae
• Chlamydophila pneumoniae

Question 7

3rdG fluoroquinolones?

Answer 7

• levo.floxacin

- moxi.floxacin

Question 8

Levofloxacin & Moxifloxacin spectrum?

Answer 8

• some activity against G-‘s
• more activity against G+’ cocci:
  1. S.pneumoniae
  2. Enterococci
  3. MRSA

Question 9

broadest spectrum fluoroquinolones?

Answer 9

moxifloxacin

• with enhanced activity against anaerobes
• Use of moxifloxacin in urinary tract infections is not recommended

Question 10

fluoroquinolones pharmacoKinetix?

Answer 10

• oral bioavailability: good
• distribution: penetrate most body tissues
• Elimination: kidneys (active tubular secretion)
• moxifloxacin: eliminated partly by hepatic and biliary excretion*
• Half-live: 3–8h

Question 11

fluoroquinolones MOA?

Answer 11

• bactericidal
• in G-‘s: inhibit inhibiting topoisomerase II –> interfere with bacterial DNA synthesis
• in G+’s: inhibits topoisomerase IV –> interfere with bacterial DNA synthesis
• exhibit postantibiotic effects

Question 12

what is PostAntibiotic effect?

Answer 12

bacterial growth continues to be inhibited even after the plasma concentration of the drug has fallen below the min inhibitory concentration of the bacterium

Question 13

Resistance against fluoroquinolones?

Answer 13

• Efflux pumps or changing porin structure –> decreased intracellular accumulation of the drug
• Point mutations in the ABx binding regions –> Changes in the sensitivity of the target enzymes

Question 14

Fluoroquinolones Clinical use?

Answer 14

• mainly in urogenital and GITIs by G-‘s:
  (gonococci, E coli, P aeruginosa, Salmonella, shigella)
• meningococcal carrier state
• tuberculosis

Question 15

Ofloxacin clinical use?

Answer 15

• eradicates Chlamydia trachomatis

- 7d of treatment is required

Question 16

Levofloxacin clinical use?

Answer 16

• community-acquired pneumonia
• against:
  1. Chlamydiae
  2. Mycoplasma
  3. Legionella

Question 17

Oxifloxacin clinical use?

Answer 17

• widest spectrum of activity
• G-‘s & G+’s
• atypical pneumonia agents
• some anaerobic bacteria

Question 18

fluoroquinolones Toxicity?

Answer 18

• Gastrointestinal distress
• not recommended for children or pregnant women because they may damage growing cartilage and cause arthropathy
• enchance theophylline and other methylxanthines Toxicity ( increase their plasma lvl)
• prolong the QT interval