fluoroquinolones Flashcards
MOA fluoroquinolones
inhibit DNA synthesis by inhibiting bacterial topoisomerase
fluoroquinolones target this in G- bacteria
DNA gyrase
fluoroquinolones target this in G+ bacteria
topoisomerase 4
concentration or time dependent?
concentration
bactericidal or bacteriostatic?
bactericidal
3 mechanisms of resistance
decreased binding affinity
expression of active efflux pump
altered cell wall permeability
has poor affinity against G+ aerobes
ciprofloxacin
have enhanced activity against G+ aerobes
levofloxacin, moxifloxacin
list of G+ aerobes that fluoroquinolones have activity against
MSSA
PRSP
fluoroquinolones have limited activity against these G+…
viridians
enterococcus
fluoroquinolones that have excellent activity against enterobacteriaceae
ciprofloxacin, levofloxacin
which fluoroquinolone has best activity against P. aeruginosa?
ciprofloxacin
which fluoroquinolones have no activity against P. aeruginosa?
moxifloxacin, gemifloxacin
has some activity against anaerobes…
moxifloxacin
given for prophylaxis with those at risk for (and has good activity against) anthrax infection
ciprofloxacin
have activity against mycobacterium tuberculosis
levofloxacin and moxifloxacin
PAE for G+ bacteria
2h
PAE for G- bacteria
2-4h
IV or PO?
PO (has good bioavailability)
which fluoroquinolone achieves good penetration in the CNS?
moxifloxacin
dosage adjustment with renal insufficiency?
yes
fluoroquinolone that undergo hepatic metabolism and elimination
moxifloxacin
use of fluoroquinolones for UTIs…
most fluoroquinolones accumulate in the urine for elimination, making them useful in treating UTIs
levofloxacin, ciprofloxacin…not gemifloxacin or moxifloxacin
removed during hemodialysis?
none
fluoroquinolones used in community acquired pneumonia
levofloxacin, moxifloxacin, gemifloxacin
used in bacterial exacerbations in CF due to P. aeruginosa infections
ciprofloxacin
used for acute chronic bronchitis and sinusitis
all fluoroquinolones
anti pseudomonal fluoroquinolones used for nosocomial pneumonia
ciprofloxacin, levofloxacin
used in bone/osteomyelitis infections
ciprofloxacin, levofloxacin, moxifloxacin
used in intraabdominal infections (anaerobic bacterial)
ciprofloxacin, levofloxacin, moxifloxacin with metronidazole
important adverse effects with fluoroquinolones: cardiac
can cause slight prolongation of QT interval, potentially leading to torsades
contraindicated in hypokalemic patients or those with an already prolonged QT interval
important adverse effects with fluoroquinolones: bone
can cause articular damage and joint swelling in children
important adverse effects with fluoroquinolones: tendons
patient should avoid exercise if tendon pain develops while on therapy
important drug interactions with fluoroquinolones
divalent/trivalent cations: will chelate any orally administered fluoroquinolone
warfarin: fluoroquinolones enhances effect
cyclosporine: metabolism may be inhibited with fluoroquinolones = potential toxicity
fluoroquinolone action in the urine
achieve a high concentration in the urine (except for gemifloxacin and moxifloxacin), making them useful in treating UTIs
removed during hemodialysis?
none
