Quinolones and fluoroquinolones

Question 1

quinolones fluoroquinolones MoA

Answer 1

inhibit DNA gyrase and topoisomerase 4 (topo2 and topo4)

Bactericidal promoting DNA breaks.

Question 2

Quinolone drug name and kinetics

Answer 2

Nalidixic acid

Not useful because of extremely rapid excretion into the urine.
Only use was UTIs, but is no longer used.

Question 3

Nalidixic acid SEs

Answer 3

Affects cartilage, contraindicated in preggos, nursing women, and all children under 18 years.

Inhibits CYP

Question 4

Fluoroquinolones drug names

Answer 4

1st gen: Norfloxacin

2nd: Ciprofloxacin
3rd: Levofloxacin
4th: Moxifloxacin Prulifloxacin

Question 5

Fluroquinolones

Kinetics, Spectrum

Answer 5

Kinetics: High oral availability, High tissue penetration but Low CNS pen.

Eleminated by kidney.

Spectrum: Primarily against G-negative aerobes, but some G+ action too

UTIs (1st and 2nd gen)
Nosocomial Respiratory infections - pseudo and enterobacter,
4th gen is excellent against S pneumoiae.

Anthrax - ciprofloxacin.

Question 6

Fluoroquinolones SEs

Answer 6

Are generally WELL tolerated. but,

Damage growing cartilage and are contra’d under 18 years.
Exception is Pseudomonas infections in Cystic fribrosis.
-can cause Tendinitis especially in elderly and corticosteroid use.

Are teratogenic and contraindicated in preggos

CNS effects: nervousness, insomnia
GABA and NMDA interactions - convulsions, psychosis

Cardio: QT prolongation and arrythmias, especially with sparfloxacin

Interactions with: Anti-arrhythmics, TCAs, Erythromycin are dangerous and affect potassium levels.

Question 7

Norfloxacin use

Answer 7

1st gen fluroquin

Very rapid excretion and low bioavailability
Like nalidixic acid its use is restricted to UTIs.
AND
Prostatitis

Question 8

Ciprofloxacin, Ofloxacin use

Answer 8

2nd gen fluroquins

Very effective against gram negatrive aerobes.
Ciproflaxin for Cystic fibrosis pseudomonas
Ciproflaxin for Anthrax

Legionella
Mycolasma
Chlamydia

Not effective against anaerobes.

2nd line for resistant TBs

Question 9

Levofloxacin use

Answer 9

3rd gen, isomer of ofloxacin

Same uses and 2nd gen, but

Less effective against pseudomonas.

More effective against G positives and atypicals.
Strep Pneumo
Mycoplasma

Also, prostatitis

Question 10

Moxifloxacin, Prullifloxacin use

Answer 10

Similar to the 4rd group with further improved action against G-positives.

Does not accumulate in urine and is not for UTIs

Major SE can select for C difficile.