Overview of antimicrobials Part I, J Kinder, DSA Flashcards Preview

Year 2 Resp Exam 2 > Overview of antimicrobials Part I, J Kinder, DSA > Flashcards

Flashcards in Overview of antimicrobials Part I, J Kinder, DSA Deck (50):
1

Goal of prophylactic therapy

prevent infection or prevent dangerous disease in those already infected

2

what is preemptive therapy

targeted therapy in high risk patients who are asymptomatic but have become infected

3

what is empiric therapy

provide antimicrobial therapy to a symptomatic patient without identification of infecting organism

4

what is definitive therapy

infecting organism is known
streamlined therapy based on susceptibility and duration

5

post Tx suppressive therapy

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

6

What is the most valuable immediate test for susceptibility of microbial agent

gram stain

7

What is MIC

minimum inhibitory [ ]
lowest [ ] of drug required to inhibit growth

8

disk diffusion method for determining suscebtibility can qualitatively measure what

susceptible or Resistant
not MIC

9

methods to determine MIC

dilution tests and optical diffusion

10

What is narrow specrum

antibacterial acts on single or limited group microorganisms

11

what is extended spectrum

active against gram + bacteria but also against significant number of gram - bacteria

12

what is broad spectrum

act on wide variety bacterial species (both gram + and -)

13

What is bacteriostatic

arrests growth and replication of bacteria
(protein synthesis inhibitors)

14

what is bactericidal

kills bacteria

15

types of bactericidal killing

[ ] dependent (inc [ ] inc killing)
time dependent )activity continues as long as serum [ ] above minimum bacterial [ ])

16

what common antibiotics are concentration dependent bactericidals

aminoglycosides and fluoroquinolone

17

what are common antibiotics that are time dependent bactericidals

B lactams and vanco

18

What are common antibacterial targets

cell wall synthesis
cell membrane synthesis
synthesis 30S and 50S ribosomal subunits
nucleic acid metabolism
function of topoisomerases
folate synthesis

19

What are 2 factors assoc with antimicrobial R

evolution
clinical/environmental practices

20

What are the R mechanisms

-reduced entry of antibiotic
-enhanced export antibiotic
-release microbial enzymes that kill antibiotic
-alteration of microbial proteins that transform pro-drugs to the effective moieties
-alteration of target proteins
-development of alternative pathways to those inhibited by antibiotics

21

penicillin structure

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

22

what determines susceptibility of penicillins

side chains

23

MOA of penicillins

inhibit transpeptidation reaction, last step in peptidoglycan synthesis
Penicillin binding proteins remove terminal D alanine
B lactams are analogs of D-ala D-ala so bind PBP and prevent their crosslinking
leads to cell autolysis

24

How does R happen to penicillins

structural differences in PBPs and dec PBP affinity for B lactams
active efflux pumps
drug destruction!!
inactivation by B lactamases

25

what are aminopenicillins used for

extended spectrum, usually given with B lactam inhibitor

26

What are the aminopenicillins

ampicillin (+/-sulbactam)
amoxicillan (+/-clavulanic acid)

27

Therapeutic use of aminopenicillins

URI (S pyogenes, S pneumoniae, H influenzae, sinusitis, otitis media, enterococcal infections)

28

What type of spectrum are anti-pseudomonal penicillins and what are they types

extended spectrum
ticarcillin (+/-clavulanic acid)
piperacillin (+/- tazobactam)

29

Therapeutic use of anti-pseudomonal penicillins

serious gram - infections, hospital acquired pneumonia, immunocompromised patients, bacteremia, burn infections, UTI

30

What are the adverse effects of anti-pseudomonals

allergic rxns, anaphylaxis, interstitial nephritis (rare), nausea, vomiting, mild-severe diarrhea, pseudomembranous colitis

31

cephalosporins have same MOA and R as what class of antibiotics

penicillins

32

cephalosporins do not have activity for what microbes

MRSA, listeria or enterococci

33

activity of 3rd generation cephalosporins

less active against gram +
more active against enterobacteriae

34

What drugs are 3rd generation cephalosporins

Ceftriaxone, ceftazidime

35

Tx use of 3rd generation cephalosporins

DOC serious gram - infections (Klebsiella, enterobacter, Proteus, Providencia, Serratia, Haemophilus)

36

ceftriaxone is DOC for what

all forms gonorrhea and severe lymes disease, meningitis

37

activity of 4th generation cephalosporins

extends spectrum beyond 3rd generation
serious hospitalized patients

38

What drugs are 4th generation cephalosporins

cefepime

39

Therapeutic use of cefepime

empiracal Tx of nosocomial infections

40

adverse effects cefepime

1% cross reactivity to penicillins, diarrhea, intolerance to alcohol

41

MOA and R carbapenems is similar to what other drug class

penicillins

42

spectrum of carbapenems

aerobic and anaerobic microorganisms, gram +, excellent against enterobacteriacae, PSeudomonas, Acinetobacter

43

Therapeutic uses of carbapenems

UTI, lower RTI, intra-abdominal, gynecological, SSTI, bone and joint infections
ALL IV or IM

44

what is beneficial about ertapenem

longer half life which allows for once daily dosing

45

Adverse effects of carbapenems

nausea/vomiting, seizures, HS

46

MOA glycopeptides

inhibits cell wall synthesis binding with high affinity to D alanylD alanine terminal
Unable to penetrate outer membrane gram - bacteria

47

Bacterial Resistance of glycopeptides

alteration of Dalanyl D alanine to D alanyl D lactate or serine

48

spectrum of glycopeptides

broad gram + coverafe inclusing MRSA, MRSE
all gram - and mycobacterium resistant

49

Therapeutic use of glycopeptides

osteomyelitis, endocarditis, MRSA, strep, enterococci, CNS infections, bacteremia,
orally for Clostridium difficile!

50

adverse effects glucopeptides

macular skin rash, chills, fever,rash
red man synfrome from rapid infusion
release of histamine from toxic effect vanco
ototoxicity and nephrotoxicity