14. Quinolones and fluoroquinolones

Question 1

Quinolones

Answer 1

Nalidixic acid

Question 2

Nalidixic acid

Answer 2

non fluorinated quinolone
Too rapid excretion into the urine → use in lower urinary tract infections

Spectrum: G-ive aerobic

Adverse effect: GI and CNS

Question 3

how many Fluoroquinolones generations

Answer 3

4

Question 4

1st generation

Answer 4

Norfloxacin

Question 5

2nd generation

Answer 5

Ciprofloxacin

ofloxacin

Question 6

3rd generation

Answer 6

Levofloxacin

Question 7

4th generation

Answer 7

Moxifloxacin

Question 8

Fluoroquinolones

Answer 8

have the suffix -oxacin
Bactericidal (AUC : MIC)
Blocks replication by inhibiting topoisomerase II (DNA gyrase) and topoisomerase IV

In G-ive inhibition of topoisomerase II (DNA gyrase) is more significant
In G+ive inhibition of topoisomerase IV is more significant

Absorption: interference if di-valent are found
Distribution: good to tissues (especially bones) | intracellular (macrophages)

Adverse effects: generally well tolerated drug | Tendinitis, damage cartilage

Question 9

Norfloxacin

Answer 9

Spectrum: most G-ive aerobe bacteria, ProteusE.coliKlebsiella, H, influenzae, Nissera

Kinetics: Lower bioavailability - too rapid renal excretion
Administration: oral

Clinical use: UTI, Enteritis, Prostatitis
Adverse effect: GI, CNS

Question 10

Ciprofloxacin

Answer 10

Spectrum: better G-ive aerobe bacteria & pseudomonas

Kinetics: good bioavailability
renal excretion
Administration: Oral and IV | ophthalmic

Clinical use: used in CF | Bacterial diarrhea (salmonella typhi, E.coli) | 2nd line tuberculosis

Adverse effect: GI, CNS, bone-cartilage in adolescence, drug interaction (warfarin and cyclosporine)

Question 11

Levofloxacin

Answer 11

L- isomer of ofloxacin (2nd gen.)

Spectrum: similar to 2nd gen - better G+ive (Strep pneumoniae) | less pseudomonas
Clinical use: respiratory oriented | prostatitis | skin infection

Kinetics: 100% bioavailability
renal excretion
Administration: Oral and IV | ophthalmic

Adverse effect: GI, QT prolongation

Question 12

Moxifloxacin

Answer 12

Spectrum: similar to 3rd gen - better G+ive | some anaerobes as well
Clinical use: similar to 3rd | Not for UTI

Kinetics: good absorption
long half life (once a day administration)
liver excretion
Administration: IV | Ophthalmic

Adverse effect: GI, CNS, QT prolongation