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Flashcards in Cell Wall Synthesis Inhibitors Deck (39):
1

Cephalosporins: antibiotic type

cell-wall synthesis inhibitor; B-lactam antibiotic

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Cephalosporins: mechanism of action

inhibit cell-wall synthesis in stage 3: peptidoglycan cross-linking

3

Cephalosporins: susceptibilities

1. cephalosporinase 2. less susceptible to penicillinase/B-lactamases than penicillins

4

Cephalosporins: pharmacokinetics

oral & parenteral admin; penetrates well into most tissues except brain/CSF; primarily renal extcretion

5

Cephalosporins: major classifications

first generataion (e.g. Cefazolin), second generation (e.g. Cefuroxime), third generation (Cefdinir), fourth generation (Cefepime), and "fifth"/next generation (ceftaroline)

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Cephalosporins-1st Generation: spectrum

gram+ cocci (e.g. staph/strep but not enterococci/MRSA), gram- cocci, gram- bacilli (e.g. E. Coli UTIs)

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Cephalosporins-2nd Generation: spectrum

maintain 1st gen. coverage + extended activity against gram- bacteria + anaerobes (bacteriodes); no pseudomonas

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Cephalosporins-3rd Generation: spectrum

expanded gram- coverage (enteric gram- bacilli; e.g. N. gonorrheae); some have moderate antipseudomonal

9

Cephalosporins-4th Generation: spectrum

good against pseudomonas and S. pneumonaie

10

Cephalosporins-5th Generation: spectrum

MRSA

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Cephalosporins: adverse reactions/tocivity

allergy/hypersensitivity (not as severe as penicillins, but don�t use if documented immeadeate penicillin rxn), nausea/vomit, superinfection w/broader spectrum agents, can intensify effect of oral anticoagulants

12

Carbapenems: antibiotic type

cell-wall synthesis inhibitor

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Carbapenems: mechanism of action

inhibit cell-wall synthesis in stage 3: peptidoglycan cross-linking; bactericidal

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Carbapenems: susceptibilities

B-lactamase resistant

15

Carbapenems: pharmacokinetics

parenterally only (IV/IM); penetrates all tissues including CSF; renal excretion

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Carbapenems: major clinical uses

resrved for treatment of infections resistant to multiple drugs

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Carbapenems: spectrum

1. gram+ aerobic+anaerobic 2. gram- aerobic+anaerobic (e.g. bacteriodes) 3. enterocci 4. gram - bacilli (Pseudomonas aeruginos, E. Coli)

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Monobactam: mechanism of action

inibit cell wall synthesis

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Carbapenems: susceptibilities

B-lactamase resistant

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Carbapenems: pharmacokinetics

no oral, use IM; widely distributed, including CSF; kidney excretion

21

Carbapenems: major clinical uses

gram - bacilli; syngerm w/aminoglycosides against P. aeruginosa

22

Penicillins: antibiotic type

cell-wall synthesis inhibitor; B-lactam antibiotic

23

Penicillins: mechanism of action

inhibit cell-wall synthesis @ stage 3: peptidoglycan cross-linking; bind to penicillin binding proteins (PBPs); trigger autolytic activity

24

Penicillins: susceptibilities

1. penicillinase/B-lactamases 2. altered PBPs prevent effective activity

25

Penicillins: pharmacokinetics

moderately strong acids/acid stability dictates absorption; penetrates tissues poorly except inflamed tissues/membranes; kidney excretion

26

Penicillins: major classifications

1. prototype penicillins 2. penicillinase-resistant penicillins 3. extended spectrum penicillins 4. B-lactamase inhibitor combinations

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Prototype Penicillins: Examples and use

1. Penicillin G: severe hospital infections 2. Penicillin V: acid-fast, mild-moderate infections

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Penicillinase-restitant Penicillins: Examples and use

e.g. Oxacillin -- use when penicillinase-producing organisms are encountered or renale insuffieciency (b/c renal+hepatic elimination)

29

Extended-Spectrum Penicillins: Examples and use

1. Ampicillin & Amoxicillin: gram - bacilli (but are not resistant to penicillinase 2. Anti-pseudomonal penicillins

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B-lactamase inhibitors: Examples and use

1. Clavulanic Acid 2. Sulbactam 3. Tazobactam; potent-irreversible inhibitors of B-lactamase & extends spectrum of accompanying penicillin

31

Penicillins: Gram+ cocci spectrum

1. Streptocci 2. Enterocci 3. Staphylococcus aureus

32

Penicillins: Gram- cocci spectrum

1. Neisseria meningitis 2. Neisseria gonorrhea

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Penicillins: Gram- bacilli spectrum

1. H. influenzae 2. E. Coli 3. Pseudomonas aeruginosa

34

Penicillins: Anaerobes spectrum

Bacteriodes fragilis (gram - rod)

35

Penicillins: Adverse reactions

hypersensitivity/allergy possible; most common=reversible skin rash

36

Vancomycin: mechanism of action

cell-wall synthesis inhibitor @ stage 2 (polymerization of cell wall)

37

Vancomycin: pharmacokinetics

poor oral, usually IV; renal excretion

38

Vancomycin: clinical use/spectrum

reserved for when less toxic agents ineffective or not tolerated; gram+ cocci (MRSA, strep, staph) & anaerobes (Clostridium difficile)

39

Daptomycin: clinical use/spectrum

alternative to vancomycin; action at bacterial membrane --> cell death