Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Lippincotts pharmacology 6th edition > Ch. 38 Cell Wall Inhibitors > Flashcards

Ch. 38 Cell Wall Inhibitors Flashcards

1
Q

cell wall is composed of

A

polymer called peptidogylcan that consists of glycan units joined to each other by peptide cross-links

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

are among the most widely effective and the least toxic drug known , but increased resistance has limited their use

A

penicilins

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

R substituent attached to the 6-aminopenicilanic acid residue

A

peniciilins

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

interfere with the last step of bacterial cell wall synthesis (transpeptidation of cross -linkage)

A

penicilins

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

cell lysis occurs after interference of the last step of bacterial cell wall synthesis, transpeptidation . describe cell lysis

A

osmotic pressure or activation of the autolysins

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

penicilins are inactive against

A

mycobacteria, protozoa , fungi, and viruses

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

bacterial enzymes involved in the synthesis of the cell, what are they called and what are they inactivated by?

A

they are peniciln binding protiens (PBPs) and they are inactivated by the penicilin

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

what are the 3 mechanisms of action of penicilins

A
  1. penicillin-binding proteins
  2. inhibition of transpeptidas
  3. production of autolysins
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

inhibition of transpeptidase-catalyzed reaction due to penicilins thus

A

hinder formation of the cross-links essential for the cell wall

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

autolysins are from gram(+) or gram (-) ? what are autolysins?

A

gram(+)

degradative enzymes

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

destruction of the existing cell wall caused by

A

autolysins thanks to penicilins

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

determined in part by their ability to cross the bacterial peptidoglycan cell wall to reach the PBPs in the periplasmic space

A

antibacterial spectrum

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

have cell walls that are easily traversed by penicillins , susceptible to the pencilin

A

gram (+) bacteria

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

micro organism that have an outer lipopolysaccharide membrane surrounding the cell wall that presents a barrier to the water soluble penciillins

A

gram (-) bacteria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

how is transmembrane entrance permitted in gram(-) bacteria?

A

have proteins inserted in the lipopolysaccharide layer that act as water-filled channels (called porins) to permit transmembrane entry

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

natural penicillins

A

penicillin G and penicillin V

-fermentations fo the fungus penicillium chrysogenum

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

semisynthetic penicillins

A

amoxicillin and ampicillins (aminopenicillins)

-created by chemically attaching different R groups to the 6-aminopenicillanic acid nucleus

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

cornerstone therapy for infectiinnns caused by gram(+) and gram(-) cocci , gram(+) bacilli, and spirochetes

A

penicillin G (benzyl-penicillin)

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

resistant bacteria produce

A

inactivation of b-lactamases (penicillinases), thus making penicilins susceptible

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

drug of choice for the treatment of gas gangrene (clostridium perfringens)

A

penicillins

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

drug of choice for the treatment of syphilis (treponema pallidum)

A

penicillins

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

not used for the treatment of bacteremia due to poor oral absorption

A

penicilin V

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

penicilin V has a similar spectrum to which antiobiotic?

A

penicillin G

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

penicillin V is more acid stable than penicillin G therefore

A

often employed orally

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

used to prevent gonoccoal ohthalmia in newborns

A

silver nitrate drops

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

cetriaxone with azithromycin or spectinomycin are used to treat

A

penicillinase-producing strains

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

B-lactamase (penicillinase)-resistant penicillins are

A

methicillin, nafcillin, oxacillin, and dicloxacillin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

methicillin, nafcillin, oxacillin, and dicloxacillin are used to treat

A

infections cuased by pinicillinase-producing staphylococci, including methicillin-sensitive staphylococcus aureus (MSSA)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

causes toxicity such as interstitial nephritis therefore no longer used clinically in the states, and used for laboratory testing to identify strains of S. aureus.

A

Methicillin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

minimal to no activity against gram(-) infections

A

penicillinase resistant penicilllins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

more effective against gram(-) bacilli

A

ampicillin and amoxicillin

-antibacterial spectrum similar to penicillin G

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Ampicillin is the drug of choice against

A

gram(+) Listeria monocytogenes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Ampicillin is susceptible to

A

eterococcal species

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

extended-spectrum penicllins are

A

ampicillins and amoxicillins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

widely used in the treatment of respiratory infections

A

extended spectrum antibiotics (ampicillins/amoxicillins)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

employed prophylactically be dentists to prevent high-risk patients for the prevention of bacterial endocarditis

A

amoxicillin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

why is resistance to extended-spectrum antibiotics a major clinical problem?
-E. Coli and H. influenzae are resistant

A

inactivation by plasma-mediated penicillinases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

-b-lactamase inhibitor
protects amoxicillin or ampicillin (extended-spectrum antibiotics) from enzymatic hydrolysis and extends their antimicrobial spectra.
-najeeb concept: body gaurds that protect supermodels (amoxi and ampi)

A

Clavulanic acid or Sulbactam

-beta-lactamase inhibitor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

MSSA is resistant to ampicillin and amoxicillin due to

A

without administration of b-lactamase inhibitors

Clavulanic acid or sulbactam

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

antipseudomonal penicillins

-activity against psuedomonas aeruginosa

A

piperacillin

-parental formation only

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

most potent of these antibiotics: natural penicllins, antistaphylococcal penicillin, extendend spectrum penicillins, antipseudomonal penicillins

A

piperacillin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

what are piperacillin are effective against ?

what are piperacillin are not effective against ?

A

they are effective against gram(-) bacilli

ineffective against Klebsiella because of its constitutive penicillinase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

extends the antimicrobial spectrum of these antibiotics to include penicillinase-producing organisms
-most enterobactericeae and bacteroides species

A

formulation of ticarcillin or piperacillin with clavulanic acid or tazobactam

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

how does natural resistance to the penicillins occur?

A

because they either lack a peptidoglyclan cell wall or have walls that are impermeable to the drugs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

acquired resistance to the penicillins are

A

by plasma mediated B-lactamases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

by obtaining resistance plasmids, bacteria may acquire on or more of the following properties , allowing survival in the presence of B-lactam antibiotics:

A
  • B-lactamase activity
  • decreased permeability to the drug
  • altered PBPs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

enzymes hydrolyzes the cyclic amide bond of the B-lactam ring which results

A

loss in bactercidal activity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

where do betalactamases come from ?

-constitutive

A

produced by bacterial chromosome or acquired by the transfer of plasmids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

some of the B-lactam antibiotics can be

A

poor substrates for B-lactamases and resist hydrolysis, retaining their activity against B-lactamase-producing organisms.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

organisms that secrete B-lactamases extracellularly

A

gram(+)

- B-lactamase activity (resistance)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

organisms that inactivate B-lactam drugs in the periplasmic space

A

gram(-)

- B-lactamase activity (resistance)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

prevents the drug from reaching the target PBPs

- decreased permeability of the drug (resistance)

A

decreased penetration of the antibiotic through the outer cell membrane of the bacteria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

the presence of what can reduce the amount of intracellular drug? what’s an example?

A

presence of an efflux pump

example is Klebsiella pneumoniae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

have a lower affinity for B-lactam antibiotics

A

modified PBPs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

explains MRSA resistance to most commercially available B-lactams

A

modified PBPs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

determined by the stability of the drug to gastric acid and by severity of infection

A

B-lactam antibiotics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

Administered IV or intramuscular

A 
Ampicillin/sulbactam
ticarcillin/clavulanic acid
piperacillin/tazobactam
antistaphylococcal penicillins:
-nafcillin
-oxacillin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q 
Ampicillin/sulbactam
ticarcillin/clavulanic acid
piperacillin/tazobactam
antistaphylococcal penicillins:
-nafcillin
-oxacillin
A

Administered IV or intramuscular

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

available only as oral preparations

A

Penicillin V, Amoxicillin, dicloxacillin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

depot forms , administered IM

A

procain penicillin G and benzathin penicillin G

-low levels over long periods of time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

most penicillins should be taken on an empty stomach

A

food decreases the absorption of all the penicillinase-resistant penicillins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

all the penicllins cross the placental barrier but

A

do none have teratogenic effects

63
Q

imparied renal function reveals some metabolism of

A

penicillin G

64
Q

primary excretion for most penicillins

A

organic acid (tubular) secretory system of the kidney
glomerular filtration
-also in breast milk

65
Q

patients with impaired renal function must have dosage regimens adjusted EXCEPT

A

antistaphylococcal penicillins:

  • nafcillin
  • oxacillin
  • primarily metabolized in the liver therefore do not require dose adjustment.
66
Q

inhibits the secretion of penicillins by competting for active tubular secretion via organic acid transporto and thus can increase blood levels

A

probenecid

67
Q

adverse reactions of penicillins

A 
hypersensitivity
diarrhea
nephritiis
neurotoxicity
hematologic toxicities
68
Q

hypersensititvity

A

5%
rashses
angioedema (lip swelling,tongue, periorbital area)
anaphylaxis

69
Q

cross alergic reactions occur in

A

B-lactam antibiotics

70
Q

to determins whether treatment with a B-lactam is safe when an allergy is noted

A

patient history regarding severity of previous reaction is essential

71
Q

pseudomembranous colitis from clostridium defficile occurs

A

with penicillin use adverse effect

72
Q

actute interstitial nephritis

A

methicillin

-no longer in clinical use in the states

73
Q

provokes seizures if injected intrathecally of if very high blood levels are reached

A

neurotoxicity caused by penicillins irritating neuronal tissue

74
Q

in the sense of neurological toxicity , penicillins cause

A

GABAnergic inhibition

-epileptic patients are at risk

75
Q

hematological toxicities:
decreased coagulations observed with high doses of?
-cytopenias have been associated with therapy of greater than 2 weeks
-blood counts should be monitored

A

piperacillin, ticarcillin, and nafcillin

-to some extent penicillin G

76
Q

7-aminocephalosporanic acid

  • produced semisynthetically
  • B-lactam antibiotics similar to penicillins
A

cephalosporins

77
Q

antibacterial spectrum of cephalosporins:

-based largely on their bacterial susceptibility patterns an resistance to B-lactamases

A

1rst generation
2nd generation
3rd generation (more potent as the generation moves on)
4th generation

78
Q

ineffective against MRSA, L. monocytogenes, C. difficile, and the enterococci

A

commercially available cephalosporins

79
Q

activity against proteus mirabilis, e. coli, K. pneumoniae

A

1rst generation cephalosporins

80
Q

resistant to the staphylococcal penicillinase ( that is , they cover MSSA)

A

1rst generation cephalosporins

81
Q

act as penicillin G substitutes

A

1rst generation cephalosporins

82
Q

greater activity against three additinal gram(-) organisms:

H. influenzae, Enterobacter aerogenes, Neisseria species

A

2nd generation cephalosporins

83
Q

activity against gram(+) organisms is weaker

A

2nd generation cephalosporins

84
Q

cephamycins?

antimicrobial coverage of cephamycins include ?

A

Cefotetan and cefoxitin

includes anaerobes (bacteroides fragilis)

85
Q

less potent than first-generation cephalosporins against MSSA, but have enhanced activity against gram(-) bacilli, as well as most other enteric organisms plus Serratia marcescens?

A

3rd generation cephalosporins

86
Q

agents of choice of treatment of meningits

A

ceftriaxone and cefotaxime

-3rd generation cephaolosporin

87
Q

activity against P. aeruginosa

A

ceftazidime

-3rd generation cephalosporin

88
Q

assoiciated with “colloteral damage”

A

3rd generation cephalosporins

-flororquinolone as well

89
Q
  • must be administered parentallly
  • wide antibacterial spectrum , with activity against streptococci, and staphylococci (only those that are methicillin suceptible)
A

4th generation cephalosporins

cefepime

90
Q

effeective against gram (-) organisms such as :

Enterobacter species, E. Coli, K. pneumoniae, P. mirabilis, and P aueruginosa

A

cefepime

4th generation cephalosporin

91
Q

Iv as a prodrug, broad-spectrum

A

Ceftaroline fosamil

-advanced generation

92
Q

only commercially available B-lactam in the states with activity against MRSA and is indicated for the treatment of complicated skin and skin structure infections and community acquired pneumonia

A

Ceftaroline

-advanced generation

93
Q

the unique structure allows this cephalosporin to bind to PBP2a found with MRSA and PBP2x found with streptococcus pneumoniae

A

Ceftaroline

-advanced generation

94
Q

in addition to its broad gram(+) activity it also has similar gram(-) activity to the 3rd generation cephalosporin ceftriaxone

A

ceftaroline

-advanced generation

95
Q

coverage includes P. aeruginosa, extended-spectrum B-lactamase (ESBL)-producing enterobactericeae, and Acintobacter baumannii

A

ceftaroline

-advanced generation

96
Q

twice-daily dosing regimen also limits its use outside of an instiutional setting

A

ceftaroline

-advanced generation

97
Q

Cephalosporins are suceptible to

A

ESBLs

  • E. coli
  • K. pneumoniae
98
Q

most cephalosporins are administered via

A

IV or IM due to poor oral absorption

99
Q

ceftriaxone and cefotaxime are effective in the treatment of

A

neonatal and childhood meningits caused by H. influenzae

100
Q

used as a single prophylaxis dose prior to surgery because of its 1.8-hour V1/2

A

cefazolin

101
Q

active against penicillinase-producing S. aureus

A

cefazolin

102
Q

effective in most surgical procedures including orthopedic surgery due to its ability to penetrate bone

A

cefazolin

103
Q

all cephalosporins cross

A

the placenta

104
Q

doses adjusted in cases of renal dysfunction

A

cephalosporins

105
Q

elimination of ceftriaxone

-employed for patients with?

A

through bile into the feces

-for patients with renal insufficiency

106
Q

patients who should not recieve cephalosporins?

A

anaphylactic response, stevens-johnson syndrome, toxic epidermal necrolysis to penicillins
-people who have penicillin alergy (avoid or cautionary use)

107
Q

the highest rate of allergic cross sensitivity is between

A

penicillin and 1rst generation cephalosporins

108
Q

other B-lactam antibiotics

A

carbapenems

109
Q

sythetic B-lactam antibiotics

-sulfur atom of the thiazolidine ring has been externalized and replaced by a carbon atom

A

carbapenems

110
Q

carbapenem group

A

impenem, meropenem, doripenem , ertapenem , imipenem

111
Q

compounded with cilastatin to protect it from metabolism by renal dehydropeptidase

A

carbapenem

112
Q

resists hydrolysis by most B-lactamases but not the metallo-B-lactamases

A

imipenem

113
Q

active against B-lactamase-producing gram(+) and

gram(-) organisms, anaerobes, and P. aeruginosa

A

imipenem

114
Q

lacks coverage against P. aeruginosa, enterococcus species, and acinetobacter species

A

ertapemen

115
Q

IV and penetrates into CSF when there is meningitis

A

imipenem/cilastatin and meropenem

116
Q

cilastatin with imipenem prevents the

A

prevents the formation of toxic metabolite that causes nephrotoxicity

117
Q

only carbapenem that requires coadministration of cilastatin

A

imipenem

118
Q

iv or im once daily , carbapenem

A

ertapenem

119
Q

adverse effects of impenemim/cilastatin

A

nausea, vomiting, diarrhea

120
Q

high levels of which carbapenem provokes siezures?

A

imipenem

121
Q

a monobactam that distrupt bacterial cell wall synthesis

-unique because B-lactam ring is not fused to another ring

A

aztreonam

122
Q

primarily against gram(-) pathogens including enterobacteriaceae and P. aeruginosa

A

Aztreonam

123
Q

lacks activity against gram poistive organisms and anerobes

A

aztreonam

124
Q

resistant to the action of most B-lactamases with the exception of the ESBLs

A

Aztreonam

125
Q

administered IV or IM
-relatively nontoxic but may cause
phlebitis, skin rash and occasionally abnormal liver function tests

A

aztreonam

126
Q

safe alternative for patientes allergic to other penicillins, cephaolsporins or carbapenems

A

aztreonam

127
Q

destroys the antimicrobial activity of a B-lactam antibiotic

A

hydrolyis of the B-lactam ring

128
Q

calvulanic acid sulbactam and tazobactam are

A

b-lactamase inhibitors

-protects anitbiotics

129
Q

tricyclic glycopeptide, important in treating life threatening MRSA and methicillin-resistant Staphylococcus epidermidis (MRSE) as well as enteroccal infections

A

Vancomycin

130
Q

used in individuals with prosthetic heart valves and in patients undergoing implantation of prosthetic devices especially in hospitals with rates of MRSA or MRSE

A

vancomycin

131
Q

not absorbed after oral administration

A

vancomycin

132
Q

bacericidal concentration-dependent cyclic lipopeptide antibiotic that is an alternative to other agents such as linezolid and quinupristin/dalfopristin, for treating infections caused by resistant gram (+) organisms , including MRSA and vancomycin resistant enterococci (VRE)

A

Daptomycin

133
Q

treatment of complicated skin and skin structure infections bacteremia caused by S. aureus, including those with right-sided infective endocarditis

A

daptomycin

134
Q

inactivated by pulmonary surfactants

-should never be used in treatments of pneumonia

A

daptomycin

135
Q

bactercidad concentration-dependendent smeisynthetic lipoglycopeptide antibiotic that is a synthetic derivative of vancomycin

A

telavancin

-inhibits bacterial cell wall synthesis

136
Q

alternative to vancomycin, daptomycin and linezolid in treating complicated skin and skin structure infections caused by resistant gram(+) organisms (including MRSA)

A

telavancin

137
Q

last choice for hospital-acquired and ventilator-associated bacterial pneumonia when alternative treatments are not suitable

A

telavancin

138
Q

adverse effects of telavancin

A

teratogenic, interactions with medications that can prolong the QT interval (flouroquinolones, azole antifungals, macrolides)

139
Q

bactercidal synthetic derivative of phosphonic acid

A

fosfomycin

140
Q

blocks cell wall synthesis by inhibiting the enzyme

UDP-N-acetylglucosamine enolpyruvyl transferase, which catalyzes the 1rst step in peptidoglycan synthesis

A

fosfomycin

141
Q

fosfomycin dosage and treatments

A

1 time dose

urinary tract infections caused by E. coli and E. faecalis

142
Q

rapidly absorbed after oral administration and distributes well to kidneys, bladder, and prostate

A

fosfomycin

143
Q

excretion of fosfomycin

A

feces/urine in active form

144
Q

adverse effects of fosfomycin

A

diarrhea , vaginitis, nausea, and headache

145
Q

cation polypeptides that bind to phospholipids on vacterial cell membrane of gram(-) bacteria

A

polymyxins

146
Q

detergent like effect that distrupts cell membrane integrity leading to leakage of cellular components and ultimately cell death

A

polymyxins

147
Q

activity against gram(-) bacteria , including P. aeruginosa, E. coli, K. pneumoniae, Acinetobacter species, and enterobacter species

A

polymyxins

148
Q

allos may species of proteus and serratia to be intrinsically resistant

A

polymyxins

149
Q

polymyxins in clinical use today

A

polymyxins B and colistin (polymyxin E)

150
Q

available in parenteral, ophthalmic, otic , and topical preparations

A

Polymyxin B

151
Q

Colistin only available as a prodrug

A

colistimethate sodium, administered via IV or nebulizer (inhaled)

152
Q

increases risk of nehprotoxicity and neurotoxicity (slurred speech, muscle weakness) when used systematically

A

Colistimethate sodium (prodrug of colistin)

153
Q

salvage therapy for patients with multidrug-resistant infections

A

colistimethate sodium (prodrug of colistin)

Lippincotts pharmacology 6th edition (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions