Inhibitors Of Cell Wall Synthesis Flashcards

1
Q

Beta-Lactam structure

A

Essential for activity
structural analog of D-Ala-D-ALA residue of NAM/NAG

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2
Q

Beta-lactam ring has high affinity for

A

Bacterial PBPs

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3
Q

Beta-lactam mechanism of action

A

T>MIC
Irreversible inhibition of PBPs=autolysin activation

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4
Q

Penicillin resistance due to

A

decreased permeability
Mutation in PBPs (G+ strains)
Enzymatic inactivation (beta-lactamase, ex.ESBL)

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5
Q

Penicillin G and V are active against

A

G+ cocci/bacilli
Anaerobes
NOT G- cocci, beta-lactamase producing strains

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6
Q

Penicillin G is given

A

IV or IM

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7
Q

Penicillin V is given

A

Orally

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8
Q

Nafcillin is active against

A

PCN G-resistant methicillin susceptible staph (MSSA) and streptococci

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9
Q

Methicillin is not used because

A

It causes acute interstitial nephritis

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10
Q

MRSA has emerged due to

A

Altered PBPs

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11
Q

PBP2/mecA is resistant to all beta-lactams except

A

Ceftaroline

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12
Q

Amoxacillin is active against G- bacilli due to

A

Charged amino group that enables transfer though outer membrane porins

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13
Q

Piperacillin-tazobactam has better activity against G- strains (notably P. Auriginosa) due to

A

Modified amino-PCN R group

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14
Q

Clavulate and tazobactam role

A

Protect antibiotics from inactivation by beta-lactamases in G- bacteria

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15
Q

Beta lactamase have _ half lives

A

Short

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16
Q

Penicillin G benzathine is given_

A

IM weekly

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17
Q

_ prolongs penicillin duration by extending half life

A

Probenecid

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18
Q

Adverse reactions of penicillins include

A

Nausea/diarrhea
Maculopapular rashes (amino penicillins-amoxacillin, esp in people with EBV)
Allergy- urticarial rash

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19
Q

Aminopenicillins

A

Amoxacillin

20
Q

Extended-spectrum penicillins (aka anti-pseudomonal)

A

Piperacillin-tazobactam

21
Q

Beta-lactamase inhibitors

A

Clavulanate
Tazobactam

22
Q

Cephalosporin resistance due to

A

Production of beta-lactamases and altered PBPs

23
Q

1st generation cephalosporin

A

Ceftazolin

24
Q

Ceftazolin is used for

A

Prophylaxis against surgical site infections (MSSA and strep)

25
Q

2nd generation cephalosporin

A

Cefoxitin (subgroups- cephamycins and cephalosporins)

26
Q

3rd generation cephalosporin

A

Ceftriaxone

27
Q

Ceftriaxone is useful for treating

A

G- meningitis (ESBL bacteria are resistant)

28
Q

5th generation cephalosporin

A

Ceftaroline

29
Q

_ is the only beta lactam active against MRSA

A

Ceftaroline

30
Q

Carbapenems

A

Imipenem-cilastatin

31
Q

_ are highly resistant to inactivation by beta lactamase

A

Carbapenems

32
Q

Carbapenems are given

A

Parenterally and eliminated by kidneys

33
Q

Imipenem is combined with cilastatin to

A

Block host renal inactivation

34
Q

Carbapenems are used for

A

Resistant infections
Anaerobics
Mixed infections

35
Q

Monobactams

A

Aztreonam

36
Q

Aztreonam is only active against

A

G- aerobes

37
Q

Glycopeptides

A

Vancomycin

38
Q

Glycopeptides mechanism of action

A

Bactericidal
AUC/MIC
Binds D-ALA-D-ALA of NAM blocking addition to the chain

39
Q

Vancomycin is only active against

A

G+
Only given orally for C. Diff

40
Q

Vacomyicin is _toxic

A

Oto and nephro
Can also cause flushing reaction

41
Q

Phosphoenolpyruvate analogs

A

Fosfomycin

42
Q

Fosfomycin mechanism of action

A

Inhibits production of Mur A enzyme which synthesizes NAM
Enter bacteria via glycerophosphate transporter (not present in mammals

43
Q

Fosfomycin is only used against

A

Urinary pathogens

44
Q

Beta lactam inhibitors of cell wall synthesis

A

Penicillin V, G
Nafcillin
Amoxicillin (-clavulonate)
Piperacillin-tazobactam

Cefazolin
Cefoxitin
Ceftriaxone
Cefepime
Ceftaroline

Imipenem-cilastatin
Aztreonam

45
Q

Non-beta-lactam cell wall synthesis inhibitors

A

Vancomycin

Fosfomycin