Fluoroquinolones/UTI drugs

Question 1

Fluoroquinolone drugs

Answer 1

Ciprofloxacin
Ofloxacin
Levofloxacin
Moxifloxacin
Gatifloxacin
Gemifloxacin

Question 2

MOA of fluoroquinolones

Answer 2

inhibit DNA gyrase, which prevents relaxation of positively supercoiled DNA that is required for normal transcription and replication (Topo IV); bactericidal

Question 3

Fluroquinolone spectrum

Answer 3

aerobic G- rods, good G+ (Exception: moxi and gemi effective against anaerobes)

Question 4

Cirpofloxacin use

Answer 4

UTI, anthrax prophylaxis, P. aeruginosa

Question 5

Ofloxacin

Answer 5

PROSTATITIS, TB

Question 6

Levofloxacin

Answer 6

CAP

Question 7

Moxifloxacin

Answer 7

anaerobes; active against PCN resistant S. pneumoniae

Question 8

Gatifloxacin

Answer 8

ocular application only

Question 9

Gemifloxacin

Answer 9

active against penicillin resistant S. pneumoniae, anaerobes, CAP

Question 10

Fluroquinolone kinetics

Answer 10

oral
wide distribution, excellent tissue penetration (prostatitis- oflox)
poor CNS
excreted by kidney (probenecid delays elimination)

Question 11

Decrease absorption of fluoroquinolones

Answer 11

Mg, Al, Ca

Question 12

Fluoroquinolones adverse effects

Answer 12

increase QT interval
cartilage erosion (don't use in children)
tendon rupture
photosensitivity

Question 13

Photosensitivity

Answer 13

fluoroquinolones, tetracyclines

Question 14

Fluoroquinolones contraindicated in

Answer 14

pregnant
nursing
children (cartilage damage) <18 YO

Question 15

Don’t use <18 YO

Answer 15

Fluorquinolones

Question 16

Resistance to fluoroquinolones

Answer 16

1. targe-site gene mutations
2. Reduced membrane permeability
3. plasmid-mediated resistance

Question 17

Metronidazole MOA

Answer 17

prodrug: non-enzymatically reduced by reacting with ferrodoxin (only found in anaerobes); metabolites are taken up into bacterial DNA and form unstable molecules (bacteriocidal)

Question 18

Reacts with ferrodoxin

Answer 18

Metronidazole

Question 19

Metronidazole spectrum

Answer 19

anaerobes (G-/+)

Question 20

Use of metronidazole

Answer 20

BV, RTI, pseudomembranous colitis (alternative to vanco), endocarditis, H.pylori

Question 21

Metronidazole kinetics

Answer 21

oral, IV, topical
liver metabolism
eliminated in urine

Question 22

Adverse effects of metronidazole

Answer 22

Dilsulfiram-like reaction
Disgeusia (metal taste)
CNS and PNS toxicity (convulsive seizures, neuropathy), GI disturbance

Question 23

Disulfiram-like reaction

Answer 23

cephalosporins and metronidazole

Question 24

Exclusive UTI drugs

Answer 24

Nitrofurantoin

Methenamine

Question 25

UTI pathogens

Answer 25

E.coli (80%), Staph saprophyticus (G+), Catheter associated UTI's (proteus, klebsiella, seratia, pseudomonas)

Question 26

Exclusive UTI drug properties

Answer 26

renal excretion achieve high urinary concentration (do no achieve therapeutic concentrations anywhere else in body) Bactericidal activity in the urine

Question 27

Nitrofurantoin

Answer 27

damages bacterial DNA; prodrug: reduced in bacterial cells to intermediate that can attack ribosomal proteins, DNA, metabolism, macromolecules

Question 28

Nitrofurantoin spectrum

Answer 28

wide spectrum; static and cidal (e. coli, S. pyogenes, Citrobacter, Klebsiella, enterobacter, shigella, serratia, and indole positive proteus)

Question 29

Resistant organisms to nitrofurantoin

Answer 29

Proteus and pseudomonas

Question 30

Use of nitrofurantoin

Answer 30

tx of uncomplicated UTI (alternative for tx of E. coli resistant to TMZ-SMX and fluroquinolones)

Question 31

Nitrofurantoin kinetics

Answer 31

rapid and complete absorption after oral use acidic urine increases therapeutic action drug activity is decreased when glomerular filtration is impaired should not be used if creatinine clearance is less than 50 mL/min (renal failure) colors urine brown

Question 32

Nitrofurantoin toxicity

Answer 32

GI upset Allergic rxn: Hemolytic anemia (G6PD deficiency) Pulmonary fibrosis (chronic use and elderly) neuro disorders

Question 33

Contraindications of nitrofurantoin

Answer 33

pregnancy (38-42 weeks gestation), less than 1 month old, impaired renal function, allergy

Question 34

Methenamine

Answer 34

oral; prodrug: decomposes to formaldehyde and ammonia in acid medium of urinary tract

Question 35

Prodrugs

Answer 35

metronidazole (ferrodoxin), nitrofurantoin (damage bacterial DNA), Methenamine (formaldehyde and ammonia)

Question 36

No bacterial resistance

Answer 36

Formaldehyde (methenamine)

Question 37

Spectrum of methenamine

Answer 37

nearly all bacteria; proteus inhibit release of formaldehyde (combine with weak organic acid: hippuric acid)

Question 38

Increases pH of urine

Answer 38

Proteus

Question 39

Toxicity of methenamine

Answer 39

non-toxic: doesn't decompose until acidic urine | some GI distress

Question 40

Contraindications of methenamine

Answer 40

``` hepatic insufficiency (conversion to formaldehyde releases ammonia, thus contraindicated in hepatic deficiency) renal insufficiency (crystalluria) ```