Antimicrobials Flashcards

Week 2 (64 cards)

1
Q

Phase I clinical trial

A

Test on healthy volunteers for safety and dose-ranging

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2
Q

Phase II clinical trial

A

Test on patients to assess efficacy, effectiveness and safety

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3
Q

Phase III clinical trial

A

Assess efficacy, effectiveness and safety

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4
Q

Narrow spectrum antimicrobial

A

Antimicrobial effective against a limited number of bacterial genera

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5
Q

Broad spectrum antimicrobial

A

Antimicrobial effective against a large number of bacterial genera

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6
Q

Give some features of the ideal antibiotic

A
  • selective toxicity
  • bacterialcidal
  • slows emergence of resistance
  • narrow spectrum of activity
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7
Q

Why is a narrow spectrum of activity ideal?

A

Doesn’t encourage resistance developing over many generas

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8
Q

4 ways to classify anti-bacterial agents

A
  1. Bacterialcidal or bacteriostatic
  2. Spectrum of activity
  3. Chemical structure
  4. Targets/selective toxicity
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9
Q

Ribosomes of bacteria

A

70s

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10
Q

Ribosomes of eukaryotes

A

80s

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11
Q

What can bacteria synthesise on their own which humans need to take in?

A

Folic acid/folate

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12
Q

Why enzyme involved in folic acid synthesis do humans also have

A

DHPS

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13
Q

2 kinds of beta-lactam antibiotics

A

penicillins

chepalosporins

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14
Q

What do beta-lactams inhibit?

A

The enzymes PBPs (penicillin binding proteins) which are required for transpeptidation of cell wall

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15
Q

Transpeptidation =

A

the last step in cross-linking of peptidoglycan cell wall

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16
Q

3 antibiotic classes that work on cell wall synthesis =

A

penicillins
cephalosportins
glycopeptides

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17
Q

broad spectrum penicillin

A

amoxicillin

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18
Q

most common glycopeptide

A

vancomycin

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19
Q

Vancomycin is only active against what type of bacteria?

A

Gr+ (MRSA)

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20
Q

Glycopeptides MoA

A

Bind to cell wall subunit and prevent incorporation of unit

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21
Q

Classes of antibiotics which inhibit protein synthesis

A
  • macrolides
  • aminoglycosides
  • tetracyclins
  • chloramphenicol
  • lincosamides
  • puromycin
  • fusidic acid
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22
Q

Macrolides

A

50S inhibitors

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23
Q

Tetracyclins

A

30S inhibitors

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24
Q

Aminoglycosides

A

30S inhibitors

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25
Classes which disrupt nucleic acid synthesis
Quinolones | Rifamycins
26
Quinolones
Inhibit DNA replication
27
Classes of antimetabolites
Sulfonamides | Trimethoprim
28
Which pathway do antimetabolites distrupt?
formation of dihydrofolic acid.
29
Sulfonamides MoA
Inhibit PABA
30
Trimethoprim MoA
Inhibits DHPS
31
Which antimetabolite inhibits an enzyme found in humans?
trimethoprim
32
Class of antibiotics which acts as a detergent on plasma membrane
Polmyxins
33
Ex narrow spectrum antibiotics
Macrolides Vancomycin penG
34
Ex broad-spectrum antibiotics
Aminoglycosides 2nd and 3rd gen cephalosporins quinolones some synthetic penicillin
35
Narrow spectrum penicillin
benzyl penicillin
36
suffix of macrolides
- thromycin
37
Bacteriostatic or bacteriocidal: aminoglycosides
both
38
What kind of bacteria are aminoglycosides best for?
Gr- aerobes
39
What can be used with an aminoglycoside to treat Gr+ infections like staph endocarditis
Beta-lactam
40
Ex of aminoglycodies
gentamicin neomycin streptomycin tobramycin
41
Side effects of aminoglycodies
ototoxicity nephrotoxic inhibit Ach release (contraindicated in MG)
42
Use of tetracylines
Acne, community acquired pneumonia, intracellular pathogens, MRSA
43
Side effects of tetracyclines
Phototoxicity tinnitus permanent teetch discoloration and delayed bone growth nephrotoxic and hepatotoxic
44
Ex of macrolides
erythormycin, azithromycin, clarithromycin
45
Bacteriostatic or bacteriocidal: macrolides
bacteriostatic
46
Spectrum of macrolides
Narrow. Gr+ aerobic, Gr- aerobic
47
Some uses of macrolides
Resp infections, STIs, H.pylori
48
DOC in pregnancy
amoxicillin
49
Bacteriostatic or bacteriocidal: cephalosporins
bacteriocidal
50
name 2 drugs that can have cross-reactivity (hint = they have a similar chemical structure)
penicillins and cephalosporins
51
DOC for MRSA
Vancomycin
52
What drug does sulfonamides increase plasma conc of?
Warfarin
53
2 antibiotics which need to be metabolised by liver first
Sulfonamides | Trimethoprim
54
Bacteriostatic or bacteriocidal: sulfonamides
Bacteriostatic (cidal when with TMP)
55
Bacteriostatic or bacteriocidal: trimethoprim
Bacteriostatic (cidal when with smx)
56
Trimethoprim contraindications
pregnancy and children (teratogenic and bone marrow suppression)
57
Stages of antibiotic resistance/sensitivity
sensitive intermediate resistance
58
What does 'intermediate' mean in terms of antibiotic resistance
higher dose of antibiotic needed
59
Minimum inhibitory concentration =
Minimum conc below which bacterial growth is not inhibited (need to be above MIC)
60
innate resistance
bacteria lacks a suitable target or is impermeable to the drug
61
acquired resistance
resistance acquired via mutation or gene transfer
62
Major mechanisms of bacterial resistance:
- modify target - limit access (reduce penetration, increase efflux) - bypass pathway - enzymatic inactivation
63
S.aureus developed resitance to beta-lactams in 2 ways=
beta-lactamases | alter PBP so beta-lactam can't fit
64
Ex of mechanisms which can cause multi-drug resistance
efflux pumps