Intro to Antibiotics I Flashcards Preview

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Flashcards in Intro to Antibiotics I Deck (45):
1

overprescription of antimicrobials

facilitate resistance

2

prophylactic therapy

prevent infection or prevent dangerous disease in those already infected

ex/ HIV infection to prevent opportunistic or post-exposure prophylaxis in those in contact with meningococcal meningitis

3

preemptive therapy

provide early, targeted therapy in high risk pts asymptomatic but who are infected

ex/ CMV tx if CMV + after solid organ transplant

4

empiric therapy

infecting organism not known, antibiotics streamlined based on susceptibility and duration

ex/ staph aureus bacteremia treated empirically with vancomycin

5

post-treatment suppressive therapy

cover patient with antimicrobial therapy at lower dose when infection has not been completely eradicated and immunological or anatomical defect still resent which lead to original infection

ex/ ortho implant that has become infected

6

gold standard for ID of bacteria

gram stain

7

minimum inhibitor concentration

lower concentration of drug that inhibits growth

8

dilution test

serially diluted antibiotics tested with organism

MIC determined

9

disk diffusion

antibiotic on disk
-measure size of clear zone

determine susceptible or resistant

NO MIC

10

optical diffusion

test strip with varying antibiotic concentrations on agar

determine MIC

11

narrow spectrum

single or limited group of microorganisms

12

extended spectrum

gram positive and significant number of gram negatives

13

broad-spectrum

wide variety of bacterial species
-gram positive and negatives

14

bacteriostatic

arrest growth and replication of bacteria

protein synthesis inhibitors

15

bacteriocidal

kill bacteria

16

concentration dependent

extent of killing increases with concentration

aminoglycoside
fluoroquinolones

17

time dependent

serum concentration above minimum kills bacteria

beta-lactam
vancomycin

18

tetramycin

concentration dependent

19

ticarillin

time dependent

20

resistance mechanisms

reduced entry into pathogen

enhanced export

enzymes that destroy antibiotic

proteins transform prodrugs

alteration of target proteins

alternate pathways to those inhibited by antibiotics

21

penicillins

thiazolidine ring connected to beta lactam ring
-attached to side chain

22

mechanism of penicillins

inhibit transpeptidation rxn - last step in peptidoglycan synthesis

beta-lactams are analogs of D-Ala-D-Ala
-bind PBPs - stops cross-linking of the D-Ala

covalent binding
-cell autolysis

23

bacterial resistance to beta-lactams

beta-lactamases
-drug destruction and inactivation

24

natural PCNs

PCN G and V

gram positive cocci

streptococcus pneumoniae

25

pregnant with syphilis

PCN V

no alternative - if allergic need to be desensitized

26

anti-staphylococcal PCN

PCNase resistant
-staph aureus and staph epidermidis

not MRSA

oxacillin, dicloxacillin, nafcillin

27

aminopenicillins

extended spectrum

often given with beta-lactamase inhibitor

extends beyond gram + and -

haem influenza, E. coli, proteus, listeria

ampicillin, amoxicillin

28

upper resp tract infection with s. pyogenes, s. pneumoniae, h. influenza

ampicillin (and sulbactam)

or amoxicillin (
and clavulinic acid)

29

anti-pseudomonal PCNs

pseudomonas, enterobacter, proteus


piperacillin - extends to klebsiella and anaerobes

piperacillin and ticarillin

30

hospital acquired pneumonia

anti-pseudomonal PCNs

ticarcillin or piperacillin

31

cephalosporins MOA

beta-lactam
-same as PCNs

32

cephalosporins

classified in generations

33

no cephalosprin

active against MRSA, listeria, enterococci

34

first gen cephalosporin

gram positive
moderate gram neg
orally active anaerobes

cefazolin, cephalexin

35

surgical prophylaxis

first gen cephalosporins

cefazolin
cefalexin

36

second gen cephalosporin

increased gram negative activity

cefoxitin, cefuroxime

37

bacteriodes fragilis

cefoxitin

38

third gen cephalosporin

less active gram positive and more active enterobacter

ceftriaxone
ceftazidime

39

DOC for serious gram negative infections

klebsiella, proteus, providencia, serratia, haemophilus

third gen cephalosporin

40

gonorrhea and severe lymes

ceftriaxone

41

covers pseudomonas

ceftazidime

42

fourth gen cephalosporins

serious infection in hospitalized pts

cefepime - active against pseudomonas

43

empirical tx for hospital infections

cefepime

4th gen cephalosporin

44

cross reactive with PCN

1% risk in cephalosporin use

45

intolerance to alcohol

cephalosporin adverse effect

disulram like rxn due to MTT group of cefotetan