DNA And Antimetabolites

Question 1

Quinolones and Fluoroquinolones

Answer 1

Inhibit DNA gyrase and topisomerase IV
Bactericidal
Enter via porin
Ciprofloxacin: gram - aerobes including Pseudomonas, systemic levels
Gemi and Levofloxacin: resp, PNAs, some Peudomonas, no anaerobic coverage
Moxifloxacin: resp, some anaerobes ( below the belt), Bacteroides, no Pseudomonas

Question 2

Q & F actions

Answer 2

Cleavage of DNA and cell death
Concentration dependent
Cross resistance among fluoroquinolones (mutations in topoisomerase)

Question 3

Q & F kinetics

Answer 3

Achieve high levels in most compartments except CNS
Moxifloxacin limited urinary concentrations
Chelation limits absorption

Question 4

Q & F adverse effects

Answer 4

Chelation (no children or pregnant women)
Photosensitivity
QTc prolongation
Tendinitis