DNA/metabolic dx

Question 1

Fluoroquinolones MOA

Answer 1

direct inhibitors of bacterial DNA synthesis acting as a bactericidal

Question 2

Fluoroquinolones inhibit 2 bacterial enzymes which have essential roles in DNA replications

Answer 2

1. bacterial DNA gyrase

2. topo IV

Question 3

Fluoroquinolones active

Answer 3

against many bacteria, broad spectrum

• gram negative/positive, atypical pathogens, meningococcus, pseudonomnas, Mto. Tb

Question 4

order of Fluoroquinolones that woks best for pseudomonas (gram -)

Answer 4

ciprofloxacin>levofloxacin>moxifloxacin

Question 5

order of Fluoroquinolones that woks best for gram (+)/anaerobic

Answer 5

ciprofloxacin

Question 6

penetration of fluoroquinolones

Answer 6

excellent bone and tissue penetration and CSF penetration is modest

Question 7

mechanisms of resistance of fluoroquinolones

2

Answer 7

1. prevent drug access- active efflux pumps

2. alter target- mutations in gyrase enzyme

Question 8

fluorquinolones is resistance an issue?

Answer 8

yep, it is increasing

Question 9

fluorquinolones adverse effects (2)

Answer 9

1. impact potassium channels: seizures and prolonged Qtc interval
2. impede collagen synthesis: arhritis and aneurysm dissection

Question 10

fluoroquinolones are not recommended in

Answer 10

pediatrics

but overall, try not use as recommended by the FDA

Question 11

Sulfonamides inhibit production of _____ precursors in bacteria

Answer 11

folic acid

• Bacterial cells produce folic acid from de novo whereas mammals absorb preformed folic acid from environment

Question 12

Trimethoprim acts by inhibiting _____________, the last enzyme in the folic acid metabolic pathway, and therefore also reduce the production of tetrahydrofolic acid.

Answer 12

dihydrofolate reductase

Question 13

development of resistance of bactrum

Answer 13

1. decreased permeability
2. PABA over-production
3. drug efflux
4. decreased affinity

Question 14

spectrum of action of bactrum

Answer 14

1. community strains of MRSA
2. Ecoli
3. parasite- toxoplasma gonadii
4. fungi- pneumocystis jirovecii

Question 15

in bactrum the dosing is based on

Answer 15

the trimethroprim component

Question 16

an adverse effect of bactrum is that it has drug-drug interactions and kernicterus due to its

Answer 16

high plasma protein binding

Question 17

bactrum competes for tubular secretion and thus results in

Answer 17

hyperkalemia

Question 18

metronidazole is used for

Answer 18

anaerobic organims (vaginitis and gingivitis)

Question 19

MOA of metronidazole

Answer 19

direct damage to DNA by reduction of nitro group leading to toxic intermediates thus bactericidal

Question 20

metronidazole is used most for

Answer 20

intraabdominal abscess “mixed” interactions

Question 21

adverse effects of metronidazole (3)

Answer 21

1. N/V
2. peripheral neuropathy ** with prolonged use
3. ETOH induces a disulfram like rxn