Antibiotics/Resistance Flashcards Preview

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Flashcards in Antibiotics/Resistance Deck (64)
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1

Aminoglycoside concerns

Ear and kidney toxicity

2

Aminoglycoside mechanism

Aminoglycosides bind irreversibly to bacteria 30S and 50S ribosomal subunits to prevent initiation complex formation + protein synthesis BacterioCIDAL

3

Aminoglycoside spectrum

Primarily effective against GRAM NEGATIVES but synergistic with beta-lactams for G+

4

2 drugs commonly used for anaerobes

Metranidazole or clindamycin

5

Nucleic acid synthesis inhibitor used for cryptococcus meningitis

5-FC

Bone marrow toxicity and resistance can develop in days so always use in combination

6

Antifungal with ability to form pore in cell wall

Amphotericin B

7

Azole mechanism

Inhibition of cytochrome P-450 to block synthesis of ergosterol

8

Echinocandins do not work on...

Zygomycetes

9

Target of echinocandins

Block B-1,3-glucan synthase inhibitors

10

Good drug for mycoplasma (no cell wall)

Azithromycin (Macrolide)

11

Classes of beta-lactams

1. Penicillins 2. Cephalosporins 3. Monobactams 4. Carbapenems

12

Common concern for treating patients with beta-lactams

Allergies (mild to anaphylaxis)

13

Beta-lactam mechanism

inhibits cell wall synthesis by binding to and preventing PBP function of cross-linking NAM and NAG BacterioCIDAL

14

Ceftriaxone is what generation cephalosporin?

3rd

15

Cefezolin is what generation cephalosporin?

1st often used as surgical prophylaxis

16

Subclasses of cephalosporins

1. Classified from 1st to 5th generation 1st narrow spectrum (G+) 5th broad spectrum and better with G-

17

Clindamycin limitations

Poor penetration into CSF --> don't use for meningitis

18

Clindamycin mechanism

Bind 50S ribosomal subunit, prevents elongation of peptide chains—suppresses protein synthesis (same spot as macrolides) Can be bacteriostatic or bacteriocidal

19

Fluoroquinalone spectrum with increasing generation

Early better for G- Later better for G+

20

First gen fluoroquinalone

Nalidixic acid

21

Third gen fluoroquinalone

tosufloxacin

22

Second gen fluoroquinalones

Ciprofloxacin and levofloxacin

23

Fourth gen fluoroquinalones

Moxifloxacin and Gemifloxacin

24

Fluoroquinolone mechanism

Inhibit DNA gyrase +/- topoisomerase IV to inhibit chromosomal replication BacterioCIDAL

25

Leuconostoc has intrinsic resistance to what antibiotic

Vancomycin

26

Klebsiella isolate resistant to aztreonam and ceftriaxone has what resistance mechanism?

K-1 beta lactamase

27

Macrolide side effects

GI distress

28

Macrolide spectrum

Broad-spectrum: Gram positives, some Gram-negative, anaerobes, atypical mycobacteria, and “atypical” respiratory pathogens (mycoplasma, chlamydiae, Legionella) that are less susceptible to β-lactams

29

Macrolides mechanism

Bind reversibly to 23S of rRNA of the 50S ribosomal subunit, block translocation of tRNA from acceptor to donor side on ribosome BacterioSTATIC

30

A predefined stable antibiotic gradient is present on a thin carrier strip.

E-test