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Flashcards in DNA Function Inhibitors Deck (22):
1

Fluoroquinolones: examples

-ciprofloxacin
-levofloxacin
-gemifloxacin
-moxifloxacin

2

Fluoroquinolones: mechanism of action

-DNA transcription inhibitor
-targets bacterial DNA gyrase and topoisomerase IV
-rapidly bactericidal

3

Fluoroquinolones: pharmacokinetics

-good oral, parenteral also available
-good penetration into most tissues
-primarily kidney excretion

4

Fluoroquinolones: spectrum/clinical uses

-gram+ cocci (strep. pneumoniae, MSSA)
-gram- cocci (moraxella catarrhalis)
-gram+ bacilli (bacillus anthracis)<--cipro
-gram- bacilli (pseudomonas aeruginosa, E. coli)
-anaerobes
-atypical organisms (chlamydia, mycoplasma pneuemoniae, richettsia)

5

Fluoroquinolones: adverse reactions

-well tolerated
-increased risk of tendon rupture
-GI disturbances
-drug-drug: reduced absorption w/anacids

6

Fluoroquinolones: "1st generation" + spectrum

Naldixic acid: gram- anaerobes (++)

7

Fluoroquinolones: "2nd generation" + spectrum

Cipro & Levo: gram- anaerobes (++), pseudomonas (+), gram+ (+/++)

8

Fluoroquinolones: "3rd generation" + spectrum

Gemi & Moxi: gram- anaerobes (+), pseudomonas (+/-), gram+ (++), atypical (+), anaerobes (++)

9

Nitrofurantoin: mechanism of action

-DNA damage-inducer
-concentration-dependent bacteriostatic/bactericidal effect

10

Nitrofurantoin: pharmacokinetics

-good oral
-short half-life --> urine (renal excretion)

11

Nitrofurantoin: spectrum/clinical uses

-2nd line urinary tract antiseptic (cannot safely reach plasma levels, but concentrated in renal tubules)
-E. coli & enterocci

12

Nitrofurantoin: adverse reactions

-GI disturbances
-possible link to birth defects

13

Metronidazole: mechanism of action

-DNA damage inducer
-prodrug-->reactive nitro radical anion
-radical anion damages DNA
-bactericidal

14

Metronidazole: pharmacokinetics

-good oral
-good distribution (including bone/CSF)
-liver metabolism
-excreted in breast milk

15

Metronidazole: spectrum/clinical uses

-anaerobes (C. difficile, Bacteriodes fragilis)
-protozoa

16

Metronidazole: adverse reactions

-some GI disturbance
-headaches, dry mouth
-candidal superinfection

17

Sulfonamides: mechanism of action

-DNA synthesis inhibitor
-inhibits folic acid synthesis (PABA analog) which is required for DNA synthesis
-bacteriostatic

18

Sulfonamides: pharmacokinetics

-good oral (best on empty stomach)
-widely distributed
-some protein binding
-n-acetylation metabolism (can be toxic)
-excreted by kidney

19

Sulfonamides: spectrum/clinical uses

-broad spectrum; most common use in TMP/SMX form
-gram+ cocci (MRSA)
-gram- cocci (Moraxella catarrhalis)
-gram- bacilli (enetrobacter, shigella, pseudomonas aeruginosa)
-atypical (chlamydia)

20

Sulfonamides: adverse reactions

-generally safe
-sensitization reactions
-drug-drug: displace from proteins --> bilirubin, anticoagulants

21

Sulfonamides: bacterial resistance

-widespread in vivo
-acquired: increase PABA production or DHPS altered to decrease binding to sulfonamides
-escape: obtain end products of metabolic pathway from pus (why we must drain some purulent infections)
-natural: organisms w/no folic acid requirement

22

Sulfonamides: common drug combination

-synergy w/trimethoprim (TMP)
-sulfamethoxazole + TMP (aka TMP/SMX or "Bactrim"= bactericidal