Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

RW Pathology > Antibiotics > Flashcards

Antibiotics Flashcards

1
Q

Mechanism of action of Antibiotics

A 
Inhibit cell wall synthesis
------- β lactams(Penicillin, Cephlosporin, Carbapenems)
------- Glycopeptides (Vancoymycin, Teicoplanin)
Inhibit protein synthesis
------- Aminoglycosides (Gentamicin)
------- Tetracycline (Doxycycline)
------- Macrolide (Erythromycin)
------- Chloramphenicol
------- Oxazolidinones (Linezolid)
Inhibit DNA synthesis
------- Fluoquinolone (Ciprofloxacin)
------- Nitroimidazoles (Metronidazole)
Inhibit RNA synthesis
------- Rifamycin (Rifampacin)
Cell membrane toxin
------- Polymyxin (Colistin)
------- Cyclic lipopeptide (Daptomycin)
Inhibit folate metabolism
------- Sulfonamide (Sulphamethoxazole)
------- Diaminopyramidines (Trimethoprim)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Differences in cell structure in Gram +ve and Gram -ve

A

Gram +ve have thick peptidoglycan cell wall

Gram -ve have thin peptidoglycan cell wall + outer membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Inhibit cell wall synthesis

A
  • —– β lactams(Penicillin, Cephlosporin, Carbapenems)

- —– Glycopeptides (Vancoymycin, Teicoplanin)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Examples of βlactams

A 
Penicillin
---- Benzylpenicillin
Cephalosporin
---- 3rd gen: Ceftriaxone, Cefotaxime, Ceftrazidime
---- 2nd gen: Cefuroxime
---- 1st gen: Cephalexin
Carbapenams
---- Meropenam
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

MOA of β lactams

A

Bind to penicillin-binding proteins –> ↓cell wall cross links –> weaker membrane –> lysed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Risk of cross-reactivity between βlactams

A

0.1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Co-amoxiclav

A

Amoxicillin + Clavulanic acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Tazocin =

A

Piperacillin + Tazobactam

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

With ↑generation of cephalosporin

A

↑Gram -ve cover, ↓Gram +ve cover

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Why is Cef (cephalosporin) often given with Metronidazole

A

Met provides anerobe cover

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

ESBL stands for

A

Extended spectrum β-lactams

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

ESBL Tx

A

Carbapenam-sensitive

Resistant to Penicillin and Cephalosporins)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Carbapenemase

A

Resistant to Pencillin, Cephalosporin and Carbapenem

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Inhibit protein synthesis

A

Inhibit protein synthesis (cATOM)

  • —— Aminoglycosides (Gentamicin)
  • —— Tetracycline (Doxycycline)
  • —— Macrolide (Erythromycin)
  • —— Chloramphenicol
  • —— Oxazolidinones (Linezolid)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Example of Glycopeptides

A

Vancomycin, Teicoplanin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

MOA of Glycopeptides

A

Bind to enzymatic target (peptidoglycan precursors) –> weakened cell wall –> lyse
Similar MOA in β lactams bt bind to substrate (precursors)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Nephrotoxic ABx

A

Gentamicin, Amikacin (aminoglycosides)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Example of Aminoglycoside

A

Gentamicin, Amikacin, Tobramycin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

MOA of Aminoglycosides

A

Aminoglycoside binds to 30S ribosomal subunit to prevent causing misreading of dcodons along the mRNA–> inhibits protein synthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Example of Tetracycline

A

Doxycycline

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

MOA of Tetracycline

A

Binds to 30S ribosomal subunit to prevent aminoacyl-tRNA binding –> inhibits protein synthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Example of Macrolide

A

Azithromycin, Clarithromycin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

MOA of Macrolide

A

Binds to 50S ribsomal subunit –> prevents binding of peptidyl-tRNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

MOA of Chloramphenicol

A

Binds to 50S ribsomal subunit –> Prevents formation of peptide bonds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Example of Oxazolidinone
Linezolid
26
Inhibit DNA synthesis
Inhibit DNA synthesis - ------ Fluoquinolone (Ciprofloxacin) - ------ Nitroimidazoles (Metronidazole)
27
MOA of Oxazolidinone
Binds to 23S component of 50S subunit to prevent formation of functional 70S initial complex
28
Example of Quinolone
Ciprofloxacin
29
MOA of Fluroquinolone
Bind to DNA gyrase --> inhibit DNA synthesis
30
Example of Nitroimidazole
Metronidazole, Nitrofurantoin (related)
31
MOA of Nitroimidazole
Under anerobic conditions, active intermediated is produced which causes DNA strand breakage
32
Inhibit RNA synthesis
Inhibit RNA synthesis | ------- Rifamycin (Rifampacin)
33
Example of Rifamycin
Rifampicin
34
MOA of Rifampicin
Binds to RNA polymerase --> inhibits initiation --> Inhibits RNA synthesis S/E organse secretions, Liver enzyme inducer
35
Cell membrane toxin
Cell membrane toxin - ------ Polymyxin (Colistin) - ------ Cyclic lipopeptide (Daptomycin)
36
Examples of cell membrane toxins + MOA
Daptomycin - inserts into cell membranes --> leak ions | Colistin --> unknown
37
Inhibit folate metabolism
Inhibit folate metabolism - ------ Sulfonamide (Sulphamethoxazole) - ------ Diaminopyramidines (Trimethoprim)
38
Example of Sulfonamide + MOA
Sulphmethoxazole --> interferes with folate metabolism
39
Example of Diaminopyrimidine + MOA
Trimethoprim --> interferes with folate metabolism
40
Co-trimoxazole =
Sulphamethoxazole + Trimethoprim
41
Mechanisms of ABx resistance
BEAT drug action - Bypass ABx sensitive step in pathway (Trimethoprim) - Enzymatic drug inactivation (β lactamase) - ↓ Accumulation of drug (Tetracycline resistance) - ↓ uptake or efflux - change drug Target (MRSA, Quinolone resistance)
42
β-lactamases - types, act against
Breaks down β lactams - β-lactamase (against Penicillin) - ESBL (against cephalosporins) - AmpC (against cephalosporins, not inhibited by Clavulanic acid) - Carbapenemase (against all β lactams)
43
MRSA - resistance mechanism
Altered target (mecA gene encodes novel PBP called PBP-2a)
44
Abx for ESBL
β-lactam + Aminglyocoside (Gentamicin, Amikasin)
45
ABx for MRSA
Vancomycin (or Linezolid)
46
Abx for C diff
Metronidazole (or Vancomycin)
47
Abx for Chlamydia
Doxycycline
48
ABx for bacterial conjunctivitis
Chloramphenicol
49
ABx for VRE
Linezolid | Daptomycin
50
Cover for anerobes
Metronidazole
51
ABx fo PCP
Co-trimoxazole = Trimethoprim + Sulphamethoxazole
52
ABx for UTI
Trimethoprim or Nitrofurantoin
53
ABx for pseudomonas
Gentamicin, or Tazocin
54
Main ABx for S aureus
Flucluoxacillin
55
Main ABx for meningitis
Ceftriaxone +/- Amoxicillin (listeria cover)
56
ABx for pharyngitis
Benzylpenicillin
57
ABx for CAP (mild)
Amoxicillin
58
ABx for CAP (severe)
Co-amoxiclav + Clarithromycin
59
ABx for HAP
Amoxicillin + Gentamicin OR Tazocin
60
Abx for E. coli
Gentamicin

RW Pathology (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions