Cell Wall Synthesis Inhibitors

Question 1

Cephalosporins: antibiotic type

Answer 1

cell-wall synthesis inhibitor; B-lactam antibiotic

Question 2

Cephalosporins: mechanism of action

Answer 2

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

Question 3

Cephalosporins: susceptibilities

Answer 3

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

Question 4

Cephalosporins: pharmacokinetics

Answer 4

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

Question 5

Cephalosporins: major classifications

Answer 5

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

Question 6

Cephalosporins-1st Generation: spectrum

Answer 6

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

Question 7

Cephalosporins-2nd Generation: spectrum

Answer 7

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

Question 8

Cephalosporins-3rd Generation: spectrum

Answer 8

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

Question 9

Cephalosporins-4th Generation: spectrum

Answer 9

good against pseudomonas and S. pneumonaie

Question 10

Cephalosporins-5th Generation: spectrum

Answer 10

MRSA

Question 11

Cephalosporins: adverse reactions/tocivity

Answer 11

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

Question 12

Carbapenems: antibiotic type

Answer 12

cell-wall synthesis inhibitor

Question 13

Carbapenems: mechanism of action

Answer 13

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

Question 14

Carbapenems: susceptibilities

Answer 14

B-lactamase resistant

Question 15

Carbapenems: pharmacokinetics

Answer 15

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

Question 16

Carbapenems: major clinical uses

Answer 16

resrved for treatment of infections resistant to multiple drugs

Question 17

Carbapenems: spectrum

Answer 17

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

Question 18

Monobactam: mechanism of action

Answer 18

inibit cell wall synthesis

Question 19

Carbapenems: susceptibilities

Answer 19

B-lactamase resistant

Question 20

Carbapenems: pharmacokinetics

Answer 20

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

Question 21

Carbapenems: major clinical uses

Answer 21

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

Question 22

Penicillins: antibiotic type

Answer 22

cell-wall synthesis inhibitor; B-lactam antibiotic

Question 23

Penicillins: mechanism of action

Answer 23

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

Question 24

Penicillins: susceptibilities

Answer 24

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

Question 25

Penicillins: pharmacokinetics

Answer 25

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

Question 26

Penicillins: major classifications

Answer 26

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

Question 27

Prototype Penicillins: Examples and use

Answer 27

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

Question 28

Penicillinase-restitant Penicillins: Examples and use

Answer 28

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

Question 29

Extended-Spectrum Penicillins: Examples and use

Answer 29

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

Question 30

B-lactamase inhibitors: Examples and use

Answer 30

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

Question 31

Penicillins: Gram+ cocci spectrum

Answer 31

1. Streptocci 2. Enterocci 3. Staphylococcus aureus

Question 32

Penicillins: Gram- cocci spectrum

Answer 32

1. Neisseria meningitis 2. Neisseria gonorrhea

Question 33

Penicillins: Gram- bacilli spectrum

Answer 33

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

Question 34

Penicillins: Anaerobes spectrum

Answer 34

Bacteriodes fragilis (gram - rod)

Question 35

Penicillins: Adverse reactions

Answer 35

hypersensitivity/allergy possible; most common=reversible skin rash

Question 36

Vancomycin: mechanism of action

Answer 36

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

Question 37

Vancomycin: pharmacokinetics

Answer 37

poor oral, usually IV; renal excretion

Question 38

Vancomycin: clinical use/spectrum

Answer 38

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

Question 39

Daptomycin: clinical use/spectrum

Answer 39

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