FQ

Question 1

MOA

Answer 1

Inhibit DNA synthesis by inhibiting bacterial topoisomerases

DNA gyrase (topo II)–> prevents the relaxation of positively supercoiled DNA
- Primary target in Gram (-) bacteria

Topoisomerase IV–> essential for separation of interlinked daughter cells
- FQ interfere with separation of daughter cells
- Primary target for Gam (+) bacteria

Bactericidal–> concentration-dependent (fastest killers)

Question 2

MOR

Answer 2

Alteration in binding sites leading to decreased binding affinity

Expression of active efflux

Altered cell wall permeability due to decreased porins

Cross-resistance occurs between FQs

Question 3

Older FQs

Answer 3

Ciprofloxacin–> PO, IV

Question 4

Newer FQs (Respiratory)

Answer 4

Levofloxacin–> PO, IV
Moxifloxacin–> PO, IV
Delafloxacin–> PO, IV

Question 5

Absorption

Answer 5

FQs are well absorbed after oral administration

Delafloxacin F= 59%
Ciprofloxacin F= 70-75%
Levo, Moxi F= > 90%

Question 6

Distribution

Answer 6

Widely distributed into the prostate, lungs, bronchial mucosa, and sputum

Some FQs have high urinary concentrations–> NOT moxi and gemi

FQs achieve minimal penetration into the CSF

Question 7

Elimination

Answer 7

Renal elimination–> levofloxacin are primarily eliminated by the kidneys
- Dose adjustments are required in renal insufficiency

Hepatic metabolism/elimination–>moxifloxacin
- No renal dose adjustments

BOTH–> Ciprofloxacin, delafloxacin, and gemifloxacin
- Dose adjustments in renal insufficiency

NONE of the FQs are removed via hemodialysis

Question 8

Ciprofloxacin

Answer 8

Spectrum:
- Gram (+) aerobes–> poor activity

• Gram (-) aerobes–> Enterobacter, Pseudomonas aeruginosa
• Atypical bacteria–> DOC for Legionella!!!

Clinical uses:
- Acute exacerbations of chronic bronchitis and sinusitis
- UTIs
- Nosocomial pneumonia
- Chronic bacterial prostatitis
- Intraabdominal infections used with metronidazole

Question 9

Levofloxacin

Answer 9

Spectrum
- Gram (+) aerobes–> PRSP, MSSA

• Gram (-) aerobes–> Enterobacter, Pseudomonas aeruginosa
• Atypical bacteria–> DOC for Legionella!!!

Clinical uses:
- Community-acquired pneumonia
- Acute exacerbations of chronic bronchitis and sinusitis
- UTIs
- Chronic bacterial prostatitis
- Intraabdominal infections used with metronidazole

Question 10

Moxifloxacin

Answer 10

Spectrum:
- Gram (+) aerobes–> PRSP, MSSA

• Gram (-) aerobes–> Enterobacter
• Atypical bacteria–> DOC for Legionella!!!

Clinical uses:
- Community acquired pneumonia
- Acute exacerbations of chronic bronchitis or sinusitis
- Intraabdominal infections (monotherapy)

Question 11

Delafloxacin

Answer 11

Spectrum:
Gram (+) aerobes–> PRSP, MSSA, MRSA

Gram (-) aerobes–> Enterobacter, Pseudomonas aeruginosa

Atypical bacteria–> DOC for Legionella!!!

Clinical uses:
- Community acquired pneumonia
- Skin and skin structure infections (MRSA)

Question 12

Adverse effects

Answer 12

GI–> N/V/D

Neurologic–> headache, confusion, agitation, dizziness, hallucinations, seizures, peripheral neuropathy

Hepatotoxicity–> trovafloxacin, moxifloxacin

Cardiac–> FQs may cause QTc prolongation, torsades
- FQs should be used in caution in patients with hypokalemia, use of Class III antiarrhythmias, preexisting QTc prolongation

Articular damage–> CI in pediatric patients and the warning to avoid use in pregnancy or breastfeeding

Tendonitis or tendon rupture–> especially in elderly

Question 13

Drug interactions

Answer 13

Divalent and trivalent cations (ZICAM)–> including antacids,ddl, sucralfate, enteral feeds IMPAIR ABSORPTION

WARFARIN

Theophylline–> cipro
Cyclosporin–> cipro