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Flashcards in Fluoroquinolones Deck (12):
1

MOA of Fluoroquinolones

Bactericidal
1. Inhibit DNA gyrase (Topoisomerase II)
-Mainly in gram (-) bacteria
-prevents relaxation of positively supercoiled DNA

2. Inhibits Topoisomerase IV
-Mainly in gram (+) bacteria
-prevents separation of replicated chromosomal DNA

2

Describe the two mechanisms of resistance to Fluoroquinolones due to mutation.

1. Mutation of GyrA or GyrB genes that code for gyrase or mutation in ParC or ParE genes that code for Topoisomease IV. Mutation lowers affinity for the drug to bind and inhibit the enzymes.

2. Mutation in the efflux pump or porins decreasing the concentration of the drug in the bacterial cell.

3

Describe the two mechanisms of Plasmid-mediated resistance to Fluoroquinolones.

1. Plamids contain a qnr gene that protects the gyrase and topoisomerase IV

2. Plasmid contains aminoglycoside acetyltransfease enzyme that modifies the drug and inactivates it

4

Which two FQs work against gram negatives

Ciprofloxacin
Levofloxacin

5

Which two FQs work against gram positives

Moxifloxacin
Gemifloxacin
(levo also woks against +'s)

6

Which of the 4 FQs work well against anaerobes?

Moxi

7

Which FQ is not metabolized in the kidneys and where is it metabolized?

Moxi
-Liver

8

The three FQs that are metabolized in the kidneys are also great for what type of infection?

UTIs

9

Which two drugs are great for serious Nosocomial infections?

Cipro, Levo

-they have a good safety rating especially for anthrax, GU infection and prostatits

10

What are cardiovascular and dematologic side effects of FQs?

Cardio: QT prolongation
Derm: photosensitivity, Stephen Johnson syndrome

11

What MSK side effects can occur while taking FQs and why?

Tendonitis or tendon rupture and/or arthropathy
-drugs can affect collagen formation and can damage cartilage

12

What neuro side effects do FQs have and why?

Peripheral Neuropathy
-drugs can inhibit GABA and adenosine receptors and result in permanent nerve damage