Antimicrobial Therapy 2 Bacterial Cell Wall Inhibitors

Front 1

what is gram negative cell's cell wall composed of?

Back 1

outer lipopolysaccharide membrane covering thin cell membrane

Front 2

what is gram positive cell's cell wall composed of?

Back 2

peptidoglycan thick cell wall, lacks outer membrane

Front 3

what must be intact in the cell wall for antibiotics to be effective?

Back 3

b-lactam

Front 4

what are peptidoglycan strands made of?

Back 4

N-acetylglucasamide and N-acetylmuramic acid

Front 5

______ cross-link adjacent peptidoglycan strands to give lattice structure for wall

Back 5

transpeptidases

Front 6

this enzyme is responsible for assembly, maintenance and regulation of peptidoglycan cell wall.

Back 6

penicillin binding protein

Front 7

E Coli PBP 1 does what?

Back 7

elongation of cell wall

Front 8

E coli PBP 2 does what?

Back 8

maintains rod shape

Front 9

E coli PBP 3 does what?

Back 9

formation of septum on division

Front 10

this form covalent bond with PBP's transpeptidases inhibiting activity

Back 10

B-lactam's

Front 11

what inhibits lipid carrier bringing strand out of cell?

Back 11

bacitracin

Front 12

this drug binds end of polypeptide chain to prevent elongation

Back 12

vancomycin

Front 13

B-lactam is bactericidal or bacteriostatic?

Back 13

bactericidal

Front 14

Name 2 natural penicillin's and list routes of administration

Back 14

Penicillin G (parenteral)
Penicillin V (oral)

Front 15

what are the natural penicillin's used for?

Back 15

streptococcal and pneumococcal infections

Front 16

name 3 penicillinase resistant drugs

Back 16

dicloxacillin
nafcillin
oxacillin

Front 17

what are penicillinase resistant drugs used for?

Back 17

penicillinase producing staphylococcal infections

Front 18

name 4 penicillin's broad spectrum drugs

Back 18

ampicillin
amoxicillin
amoxicillin+clavulanic acid
ampicillin+sulbactam

Front 19

penicillin's broad spectrum has what kind of activity? and what is it used for?

Back 19

broad spectrum has increased gram- activity

used for S.pyrogens, S. pneumoniae, H influenzae

Front 20

what do clavulanic acid and sulbactam do?

Back 20

they are penicillinase suicide inhibitors, they get chewed up so penicillin would have more activity

Front 21

name 4 penicillin's antipseudomonal drugs

Back 21

piperacillin
ticarcillin
ticarcillin+clavulanic acid
piperacillin+tazobactam

Front 22

penicillin's antipseudomonal has what kind of activity? and what is it used for?

Back 22

gram- activity

used for P. aeruginosa, Proteus enterobacter

Front 23

T/F

penicillin absorption is decreased by food

Back 23

True

Front 24

T/F

penicillin have limited lipid solubility and distributes well to tissues

Back 24

True

Front 25

Penicillin is eliminated by _____.

Back 25

active tubular secretion (acid-base transporters in kidney)

Front 26

what is probenecid used for?

Back 26

given to take up the transport system, so the penicillin will be left in the blood

Front 27

what are some of the adverse reactions of penicillin?

Back 27

allergy/sensitivity
CNS irritation: seizures
GI irritation: diarrhea

Front 28

how does resistance develop w/ penicillins?

Back 28

1. production of B-lactamases
2. addition of S.aureus or lack of specific binding to PBPs
3. cell membrane doesn't lyse after penicillin binds
4. penicillin's inactive against organism w/o cell wall (mycoplasma)

Front 29

what drug has cross sensitivity with penicillin?

Back 29

cephalosporins (2-5%)

Front 30

T/F

Cephalosporin's have good oral absorption

Back 30

False. they have poor oral absorption, most given parenteral

Front 31

what are some of the adverse reactions of cephalosporins?

Back 31

allergic/sensitivity rxns
nephrotoxicity
bleeding disorders

Front 32

why does cephalosporin's cause bleeding disorders?

Back 32

methothiotetrazole ring interferes with Vit.K, causing bleeding

Front 33

name the 4 carbapenems

Back 33

imipenem, meropenem, ertapenem, dorapenem

Front 34

what are carbapenems?

Back 34

broadest spectrum B-lactams

Front 35

what are carbapenems used for?

Back 35

Gram+, gram -, anaerobes, pseudomonas aeruginosa

Front 36

how are carbapenems administered?

Back 36

IV

Front 37

how are carbapenems excreted?

Back 37

kidney

**imipenem metabolized into nephrotoxic compound in renal tubule by dehydropeptidase, compounded with cilastatin to inhibit enzyme

Front 38

what are carbapenems indicated for?

Back 38

1.mixed aerobic and anaerobic intra-abdominal infections
2. multi-drug resistant organisms
3. serious nosocomial infection (imipenem, meropenem)
4. community acquired infections (ertapenem)
5. abdominal and complicated urinary infections (dorapenem)

Front 39

name a monobactam

Back 39

aztreonam

Front 40

what are monobactam indicated for?

Back 40

gram-, p.aeruginosa

multi-drug resistant strains

Front 41

how are monobactam's adminstered

Back 41

IV or IM

Front 42

how are monobactam's excreted

Back 42

renally

Front 43

what are some of the side effecets of monobactams

Back 43

N/V, diarrhea, seizures (if it gets to the CNS), bone marrow suppression

Front 44

what are vancomycin effective against?

Back 44

gram+, MRSA, penicillin-resistant enterococci and streptococci

Front 45

how is vanco administered?

Back 45

IV

Front 46

what is vancomycin used for/

Back 46

reserved for severe infections

pseudomembranous colitis due to clostridium difficile

Front 47

how is vanco administered for c.difficile?

Back 47

oral dose, so it stays in the GI tract

Front 48

how is vanco metabolism?

Back 48

renally

Front 49

what are the adverse effects of vancomycin?

Back 49

fever, chills, shock
redman syndrome
nephrotoxicity possible with inappropriate dosing
ototoxicity

Front 50

is daptomycin bactericidal or bacteriostatic?

Back 50

bactericidal

Front 51

what is the mechanism of daptomycin?

Back 51

binds to cell membrane resulting in depolarization and loss of membrane potential and cell death, no known resistance mechanisms

Front 52

what is daptomycin effective against?

Back 52

broad spectrum Gram+, vancomycin resistant bacteria, staphylococci, streptococci

Front 53

how is daptomycin administered? what is the dosing regimen?

Back 53

IV

once daily dosing. if CrCL<30 mL/min, dose every 48 hrs

Front 54

what is fosfomycin's mechanism?

Back 54

blocks first step of peptydoglycan synthesis

Front 55

what is fosfomycin indicated for?

Back 55

single-dose therapy for uncomplicated UTI's due to Ecoli or Enterococci faecalis

Front 56

how is fosfomycin excreted?

Back 56

concentrated and excreted unchanged in urine

Front 57

what are the adverse effects of fosfomycin?

Back 57

diarrhea, nausea/vomiting, vaginitis, asthenia (muscle weakness)

Front 58

what is the mechanism of Bacitracin?

Back 58

blocks lipid carrier molecule to move peptidoglycan to cell wall

Front 59

what is bacitracin effective against?

Back 59

gram+ bacteria

Front 60

what is bacitracin usually used for?

Back 60

used topically OTC, 1st aide cream

Front 61

what are some of the products of bacitracin?

Back 61

polymixin+neomycin (neosporin)
polymixin (polysporin)