BETA LACTAMS & CELL WAL SYNTHESIS INHIBITORS Flashcards
definition of terms, penicillins and cephalosporins (158 cards)
1
Q
antimicrobial drug that can eradicate an infection in the absence of host absence of host defense mechanisms
A
Bactericidal
2
Q
Kills bacteria
A
Bactericidal
3
Q
Does not kill bacteria
A
Bacteriostatic
4
Q
antimicrobial drug that inhibits antimicrobial growth but requires host defense mechanism to eradicate the infection
A
Bacteriostatic
5
Q
Slows down the proliferation of bacteria
A
Bacteriostatic
6
Q
Lowest concentration of antimicrobial drug capable of inhibiting growth of an organism in a defined growth medium
A
Minimum inhibitory concentration (MIC)
7
Q
Bacterial cytoplasmic membrane proteins that act as the initial receptors for penicillins and other beta-lactam antibiotics
A
Penicillin-binding proteins (PBPs)
8
Q
More toxic to the invader than to the host; a property
of useful antimicrobial drugs
A
Selective toxicity
9
Q
Bacterial enzymes involved in the cross-linking of linear peptidoglycan chains, the final step in cell wall synthesis
A
Transpeptidases
10
Q
Drugs with structures containing a beta-lactam ring: includes the penicillins, cephalosporins and carbapenems.
A
Beta-lactam antibiotics
11
Q
This ring must be intact for antimicrobial action
A
Beta-lactam antibiotics
12
Q
T or F: Beta-lactam are bactericidal drugs?
A
T
13
Q
Chains of polysaccharides and polypeptides that are cross-linked to form the bacterial cell wall
A
Peptidoglycan
14
Q
Drugs that are not as important as beta-lactam drugs
A
- Vancomycin
- Fosfomycin
- Bacitracin
(VBF)
15
Q
Major antibiotics that inhibit cell wall synthesis
A
- Penicillins
- Cephalosporin
16
Q
Bacterial enzymes (penicillinases, cephalosporinases) that hydrolyze the beta-lactam ring of certain penicillins and cephalosporins; CONFER RESISTANCE
A
Beta-lactamases
17
Q
Potent inhibitors of some bacterial beta-lactamases used in combinations to protect hydrolyzable penicillins from inactivation
A
Beta-lactam inhibitors
18
Q
Drugs that inhibit the growth/replication, or kill microorganisms
A
Antimicrobials
19
Q
What are the 5 subgroups of Antimicrobials
A
- Antibacterial (Bacteria)
- Antifungal (Fungi)
- Antiviral (Viruses)
- Anti-protozoal
- Anti-parasitic (Parasite)
20
Q
T or F:
Beta Lactams are composed of unusual 5-member ring that is common to all members
A
F, 4-member ring dapat
21
Q
Production of antibiotic-inactivating enzymes
A
Microbial Resistance
22
Q
What are the (3) bacterial cell wall synthesis inhibitors?
A
- Penicillins (Narrow spectrum, Wider Spectrum)
- Cephalosporins (Narrow spectrum, Wider Spectrum)
- Miscellaneous (Carbapenems, Aztreonam, Vancomycin
23
Q
T or F:
On Cephalosporins, 2nd to 4th generations are under narrow spectrum.
A
False, under siya ng WIDER SPECTRUM
24
Q
T or F:
On Cephalosporins, 1st generation is under narrow spectrum.
A
True
25
T or F:
On Penicillins, Penicillinase Susceptible and Penicillinase resistant.
True
26
Changes in the structure of target receptor is called?
Microbial Resistance
27
Give the Pros and Cons of Penicillin Narrow Spectrum
Pros: effective only if bacteria is susceptible
Cons: only cover few species of bacteria
28
Give the Pros and Cons of Penicillin Wider Spectrum
Pros: covers more bacteria agents
Cons: can also kill normal flora which inhibits other
bacteria, has many side effects
29
Penicillin susceptible or Penicillin resistant?
Q: Can cleave/alter penicillin
Penicillin susceptible
30
Penicillin susceptible or Penicillin resistant?
Q: Not affected by penicillin
Penicillin resistant?
31
First to suggest that a Penicillium mold (now known as Penicillium chrysogenum) must secrete an antibacterial substance
Sir Alexander Fleming
32
First to concentrate the active substance involved, which he named penicillin, in 1928
Sir Alexander Fleming
33
Derivatives of 6-aminopenicillanic acid
Penicillin
34
The beta-lactam ring structure of Penicillin is essential for?
Antibacterial activity
35
The beta-lactam ring structure of Penicillin alters what?
Pharmacokinetics (makes it more lipophilic or hydrophilic)
36
Penicillin subclasses have additional chemical substitu- ents that confer differences in what?
- Antimicrobial activity
- Susceptibility to acid and enzymatic hydrolysis
- Biodisposition (e.g. urine or bile)
37
What are the beta-lactam compounds?
- Thiazolidine ring
- β-lactam ring
38
What beta-lactam compound reacts with receptors?
Thiazolidine ring
39
What beta-lactam compound that carries a secondary amino
group (RNH–) → alters pharmacokinetics?
β-lactam ring
40
The pharmacokinetics of Penicillins vary on what?
- Vary in their oral bioavailability (F)
- Vary in resistance to gastric acid
41
T or F: Penicillins are polar?
T
42
T or F: Penicillins are metabolized extensively?
F, not metabolized extensively
43
Penicillins are usually excreted unchanged in urine via?
- Glomerular filtration
- Tubular excretion (inhibited by probenecid)
44
T or F: Penicillins must be given on an empty stomach?
T
45
Nafcillin is excreted mainly where?
Bile
46
T or F: Penicillins cross the blood-brain-barrier only when the meninges are inflammed?
T
47
T or F: Amoxicillin must be given on an empty stomach
F
48
Plasma half life of Penicillin vary from?
30 min to 1 hr
49
What are the forms of Penicillin G?
Procaine and benzathine
(administered itramuscularly)
50
Procaine and benzathine are administered via?
IM (Intramuscular)
51
Penicillins inhibit cell wall synthesis by?
- BINDING of the drug to specific enzymes (penicillin-binding proteins [PBPs]) located in the bacterial cytoplasmic membrane
- INHIBITION of the transpeptidation reaction that cross-links the linear peptidoglycan chain constituents of the cell wall
- ACTIVATION of *autolytic enzymes* that cause lesions in the bacterial cell wall.
52
Enzymatic hydrolysis of the beta-lactam ring results in the _____ _____ _______?
loss of antibacterial activity
53
Hydrolysis of the β-lactam ring by bacterial β-lactamases
Resistance
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Modification of penicillin-binding proteins [PBPs]
Resistance
55
Changes in membrane permeability
Resistance
56
In some gram-_____ _____(eg, Pseudomonas aeruginosa), changes in the porin structures in the outer cell wall membrane may contribute to resistance by impeding access of penicillins to PBPs.
gram-negative rods
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Formed by most staphylococci and gram (-) organisms
Beta-lactamases (Penicillinases)
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Inhibitors of Beta-lactamases (Penicillinases) are used in combination
with penicillin to prevent their inactivation in the following?
■ Clavulanic acid
■ Sulbactam
■ Tazobactam
59
Structural changes in target PBPs. Another mechanism of bacterial resistance is responsible for?
- Methicillin resistance (in Staphylococci)
- Penicillin G (in Pneumococci)
60
What gram-negative rod bacteria changes in the porin structures in the outer cell wall membrane may contribute to resistance by impeding access of penicillins to PBPs.
P. aeruginosa
61
Narrow spectrum Penicillinase susceptible agents includes?
- Penicillin G
- Penicillin V
62
Very narrow spectrum Penicillinase resistant agents includes?
- Methicillin (prototype - rarely used due to nephrotoxic potential)
- Nafcillin
- Oxacillin
- Cloxacillin (Dicloxacillin) - newer
63
Very-narrow-spectrum penicillinase-resistant drugs is primarily used against what bacterial infection?
Staphylococcus aureus
64
Very narrow spectrum Penicillinase resistant agents includes?
- Ampicillin and Amoxicillin
- Piperacillin and Ticarcillin
65
Penicillin G is administered via?
Parenteral
66
T or F: Penicillin G has a limited spectrum activity?
T
67
Penicillin G is used for infections caused by?
- Streptococci
- Meningococci
- Gram (+) bacilli
- Spirochetes
68
What is the causative agent of syphilis?
Spirochetes
(Treponema pallidum)
69
What bacteria/s is/are resistant via production of beta-lactamases?
- S. aureus
- N. gonorrhoeae
70
What is the drug of choice for syphilis?
Penicillin G
71
Penicillin V is used for?
Oral or Oropharyngeal Infection
72
Penicillin G are susceptible to?
Beta-lactamases
73
For Pen G:
Activity against enterococci is enhanced by coadministration of ______?
Aminogylcosides
74
Their primary use is in the treatment of known or suspected staphylococcal infections.
Very-narrow-spectrum penicillinase-resistant drugs
75
Resistant to other members of this subgroup and often to multiple antimicrobial drugs
Methicillin-resistant S. aureus (MRSA)
and
S. epidermidis (MRSE)
76
Since Methicillin is now rarely used, what are the alternative drugs used?
Oxacillin and Cloxacillin
77
These drugs make up a peni- cillin subgroup that has a wider spectrum of antibacterial activity than penicillin G
Ampicillin and amoxicillin
78
Remains susceptible to penicillinases
Ampicillin and amoxicillin
79
Their clinical uses include indications similar to penicillin G
Ampicillin and amoxicillin
80
In (1) e______ and l______infections, ampicillin is (2) synergistic with _____?
(1) enterococcal and listerial infections
(2) synergistic with aminooglycosides
81
T or F: Ampicillin and amoxicillin, when used in combination with inhibitors of penicillinases (eg, clavulanic acid), their antibacterial activity is often not enhanced
F, their antibacterial activity is often ENHANCED
82
These type of penicillin drugs have activity against several gram-negative rods
(including Pseudomonas, Klebsiella spp. & Enterobacter)
Piperacillin and Ticarcillin
83
Piperacillin and Ticarcillin enhanced activity against gram (-) rods of which bacteria?
■ Pseudomonas
■ Enterobacter
■ Some cases of Klebsiella species
84
T or F: Piperacillin and Ticarcillin have Synergistic action with aminoglycosides?
T
85
T or F: Piperacillin and Ticarcillin is susceptible to penicillinases?
T
86
Can cause interstitial nephritis more than other penicillins
Methicillin
87
This results to cross reactivity of penicillins
Allergy
88
Can cause maculopapular rash (not allergic)
Ampicillin
89
Can cause neutropenia
Nafcillin
90
caused by direct irritation or by overgrowth of gram (+) organisms or yeasts
Pseudomembranous colitis
91
Ampicillin has been implicated?
Pseudomembranous colitis
92
More stable to many bacterial β-lactamases
a. penicillins
b. cephalosporins
c. cefazolin
d. cefuroxime
b. cephalosporins
93
It has a broader spectrum of activity
Cephalosporins
94
What are the 2 sites of attachment in Cephalosporins?
R1 group
R2 group
95
modifies pharmacokinetic profile
R1 group at 3 position
96
alters antimicrobial activity
R2 group at 7 position
97
Cephalosporins is a derivate of?
7-aminocephalosporanic acid
98
T or F: Cephalosporins contains beta-lactam structure?
T
99
Most cephalosporins are administered via ____?
parenteral
100
T or F: Cephalosporins are also available for oral use?
T
(Cefdinir, Cefixime, Cephalexin)
101
Cephalosporins with SIDE CHAINS undergo _____?
a. Biliary excretion
b. Renal clearance
c. Hepatic metabolism
d. Hydrolysis
C. Hepatic Metabolism
102
Major elimination of cephalosporin is by ____?
renal tubular excretion (via active tubular secretion)
103
How many generations of drugs are present in cephalosporins?
4
104
In what generation of drugs does this happen?
"These drugs do not cross BBB and enter CSF even when the meninges are inflamed"
1st and 2nd generation drugs
105
In what generation of drugs does this happen?
"These drugs are mainly excreted in the bile"
3rd generation drug (Cefoperazone and Ceftriaxone)
106
Tor F: 1st and 2nd generation drug can be used to treat meningitis
## Footnote
mentioned in the recording
F, we cannot use 1st and 2nd generation drugs for meningitis
107
T or F: Cephalosporins are bactericidal against susceptible organisms?
T
108
T or F: Cephalosporins have a similar mechanism of action to those of penicillins?
T
(same sila na nag bbind with PBPs on bacterial cell membranes to inhibit bacterial cell wall synthesis)
109
Cefazolin, Cephalexin, and Cefadroxil are under what generation of drugs?
1st generation drugs
110
In 1st generation drugs, which one is the prototype?
Cephalexin
111
In 2nd generation drugs, which one is the prototype?
(kinuha ko lang to sa recording ni sir)
Cefuroxime
112
In 3rd generation drugs, which one is the prototype?
(kinuha ko lang to sa recording ni sir)
Ceftriaxone
113
Cephalexin is admistered via ____?
Oral
114
Cephalexin is under what generation of drugs?
1st generation drug
115
Cefazolin is admistered via ____?
Parenteral
116
Cefazolin is under what generation of drugs?
1st generation drug
117
What drugs are mainly excreted in the bile?
Cefoperazone and Ceftriaxone
118
T or F: Cephalosporins are more susceptible to penicillinase produced by staphylococci
F, less susceptible
119
MRSA (Methicillin-resistant staphylococci) are also
______ to cephalosporins
a. susceptible
b. resistant
## Footnote
from the book
b. resistant
120
They are active against gram-positive cocci, including staphylococci and common streptococci.
What generation of drugs is this this?
1st generation drugs
121
1st generation of drug has MINIMAL ACTIVITY to ____?
a. gram-negative cocci
b. enterococci
c. MRSA
d. most gram-negative rods
e. all of the above
e. all of the above
122
Cephalexin is used to treat what kind of infection?
(kinuha ko lang to sa recording ni sir)
a. Upper respiratory tract infection
b. Skin Infection
c. Both a and b
d. none of the above
c. both a and b
123
What drug in the first-generation drug has a longer duration of action and a similar spectrum of action, compared to other first-generation drugs. It penetrates well into bone
Cefazolin
124
Drugs in this subgroup usually have SLIGHTY LESS activity against gram-positive organisms than the first-generation drugs but have an EXTENDED gram-negative coverage.
2nd generation drugs
125
T OR F: Anaerobic coverage is present in 2nd generation drugs?
T
126
What drugs are under anaerobic coverage present in 2nd generation drugs?
Cefotetan, Cefoxitin
127
What 2nd generation drugs are used to treat infection caused by anaerobic Bacteroides fragilis?
Cefotetan, Cefoxitin
128
What 2nd generation drugs are used to treat sinus, ear, and respiratory infection caused by H. influenzae or M. catarrhalis?
Cefamandole, Cefuroxime, Cefaclor
129
What drug in the 2nd generation crosses the blood-brain barrier, and can be used for community-acquired bronchitis or pneumonia in the elderly and for patients who are immunocompromised
Cefuroxime sodium
130
What drug in the 2nd generation is administered twice daily? This drug is well absorbed and is active against beta-lactamase-producing organisms
Cefuroxime Axetil
131
These drugs under 3rd generation do not penetrate the blood-brain barrier.
Cefoperazone and cefixime
132
Ceftazidime, Cefoperazone and Cefotaxime are under what generation of drugs?
3rd generation
133
This generation of drugs has an INCREASED activity against gram-negative organisms resistant to other beta-lactam drugs and the ABILITY TO PENETRATE the blood-brain barrier
3rd generation
134
This drug under 3rd generation is used to treat gonococcal urethritis and it is administered via?
Ceftriaxone, administered via IV
135
Third generation drugs are most ACTIVE against what bacterias?
- Providencia
- Serratia marcescens
- Beta-lactamase producing strains of H. influenzae and Neisseria
136
Third generation drugs are LESS ACTIVE against what bacteria?
- Enterobacter strains that produce extended-spectrum beta-lactamases
137
What 3rd generation drugs are currently the most active cephalosporins against penicillin-resistant pneumococci (PRSP Strains)?
Ceftriaxone and Cefotaxime
138
This 3rd generation drug is used to treat Pseudomonas and serious infection
Cefoperazone, Ceftazidime
139
This 3rd generation drug is used to treat B. fragilis and serious infection
Ceftizoxime
140
What is the drug of choice for gonorrhea?
Ceftriaxone (parenteral) and Cefixime (oral)
141
A single injection of _______ (3rd generation drug) is usually effective as a 10-day course of treatment for otitis media with AMOXICILLIN
Ceftriaxone
142
This 3rd generation drug penetrates well into the CSF
Cefotaxime
143
This 3rd generation drugs are administered orally once daily
Cefdinir, Cefixime
144
This 3rd generation drug is excreted in bile and may be used in patients with renal insufficiency. It has good penetration into bone
Ceftriaxone
145
What 4th generation drug is more resistant to beta-lactamases produced by gram-negative organisms, including Enterobacter, Haemophilus, Neisseria, and some penicillin- resistant pneumococci?
Cefepime
146
4th generation drug that combines the gram-positive activity of first-generation agents with the wider gram-negative spectrum of third-generation cephalosporins.
Cefepime
147
4th generation drug that has activity in infections caused by methicillin-resistant staphylococci (MRSA)
Ceftaroline
148
4th generation drug that is active against Pseudomonas aeruginosa
Cefepime
149
T or F: Cephalosporins can cause allergy like skin rashes to anaphylactic shock
T
150
T or F: Complete cross-hypersensitivity exists with cephalosporins
T
151
T or F: There is a cross-reactivity between penicillin and cephalosporins
T
152
Give 3 OTHER adverse effects of cephalosporins
- Pain at IM Injection sites
- Phlebitis after IV injection
- Increase nephrotoxicity of amino glycosides
153
Drugs containing a methylthiotetrazole group such as ______, ______, & ______ may cause hypoprothrombinemia and disulfiram-like reactions with ethanol
Cefamandole, Cefoperazone, Cefotetan
154
What generation of drugs is NOT useful against Enterobacter?
2nd and 3rd generation drugs
155
What generation of drugs is USEFUL against Enterobacter infections?
4th generation drugs
156
Cephalosporins are inactive against?
- Listeria
- Atypicals
- Methicillin-resistant staphylococcus aureus (MRSA) - except ceftaroline
- Enterococcus
"LAME"
157
Renal adverse reaction of cephalosporins
Interstitial nephritis and tubular necrosis
158
Hematologic adverse reaction of cephalosporins
Hypoprothrombinemia and bleeding disorders (Cefotetan, cefamandole, cefmetazole, and
cefoperazone)
