Lecture 18 Flashcards
(108 cards)
1
Q
What chemical do agents that suppress wall synthesis attack?
A
Murein
2
Q
If there is no murein in a cell wall, what happens to the cell?
A
It bursts (lysis or plasmoptysis)
3
Q
Natural forms for antibiotics that supress cell wall synthesis tend to be what spectrum?
A
Narrow
4
Q
What are the three types of penicillin?
A
- Natural 2. Semi-synthetic 3. Repository
5
Q
Natural penicillins fall under what spectrum?
A
Narrow spectrum, most effective against G+
6
Q
Why are natural penicillins best against G+ verses G-?
A
G+ have more murein in the cell wall
a higher osmotic pressure (20-30atm)
G- have an outer membrane which blocks the penicillin
7
Q
Are natural penicillins effective against all G+?
A
No, only against growing bacteria
8
Q
Name 4 bacteria that naturall penicillins are good against
A
- Group A streptococci (like streptococci pyrogenes) because they never developed resistance
- Clodtridium perfringens (gas gangrene)
- Neisseria meningitis (G-)
- Treponema palligum (G-, syphillis)
9
Q
What is natural penicillin isolated from?
A
The mold, penicillium
10
Q
What is the common name for Benzyl Penicillin?
A
Penicillin G
11
Q
What is the mode of action for Benzyl Penecillin?
A
Suppression of cell wall synthesis
12
Q
What is the common name for Phenoxymethyl Penicillin?
A
Penicillin V
13
Q
What natural penicillin is able to resist the acid in your stomach, making it possible to take it orally?
A
Phenoxymethyl Penicillin (aka Penicillin V)
14
Q
What is the mode of action for Phenoxymethyl penicillin?
A
Suppression of cell wall synthesis
15
Q
What are repository penicillins?
A
Time-released capsules created by taking penicillin G and making it less soluble
16
Q
Name 2 repository penicillins
A
- Procane penicillin 2. Benzathine penicillin
17
Q
What is the mode of action for procane penicillin?
A
Suppression of cell wall synthesis
18
Q
What is the mode of action for benzathine penicillin
A
Suppression of cell wall synthesis
19
Q
What is benzathine penicillin used to treat
A
Infections of syphilis that are less than 1 year old
20
Q
What advantage do repository penicillins have over natural penicillins?
A
Despite having lower levels of it in the blood stream, repository penicillins last all day so that the patient doesn’t need injections hourly
21
Q
Name 4 semi-synthetic penicillins
A
- Ampicillin 2. Amoxicillin 3. Carbencillin 4. Tricarcillin
22
Q
What is the chemical makeup of ampicillin?
A
penicillin G with an amino group attached, making it broad spectrum
23
Q
Is ampicillin broad spectrum or narrow spectrum?
A
Broad
24
Q
Ampicillin is a DOC for what?
A
Very resistant UTIs caused by proteus mirabilis
25
What is the mode of action of ampicillin?
Suppression of cell wall synthesis
26
Amoxicillin is penicillin G with what group attached to it?
an OH group
27
Is amoxicillin broad or narrow specturm?
Broad
28
What is the mode of action for Carbencillin?
Suppression of cell wall synthesis
29
Carbencillin was the first drug effective against what organism?
Pseudomonas aerasinosa, but it is no longer used to treat it because there are more effective drugs on the market
30
What is the mode of action for Tricarcillin?
Suppression of cell wall synthesis
31
Tricarcillin is a DOC for?
pseudomonas aerasinosa
32
Ticarcillin is ____ times more active against ________ than carbenicillin
Ticarcillin is 2-4 times more active against pseudomonas than carbenicillin
33
Name 5 Beta-Lactamase resistant penicillins
1. Methicillini 2. Oxcillin 3. Cloxacillin 4. Augmentin 5. Zosyn
34
What does MSSA stand for?
Methicillin Sensitive Staph Areus
35
What does MRSA stand for?
Methicillin Resistant Staph Aureus
36
Why is MRSA resistant to all forms of penicillin?
They have a secondary mode of resistance, involving penicillin binding proteins, which are proteins that block pinicillin activity as well as build up murein. They also have efflux pumps, which get rid of toxins in the cells, making them resistant to aminoglycosides
37
What was the first B-lactamase penicillin?
Methicillin, but it is not longer used in America
38
What is the mode of action for methicillin?
Suppression of cell wall synthesis
39
Oxacillin is used to treat what?
More serious infections (systemic, IV, never orally)
40
What is the mode of action for Oxacillin?
Suppression of cell wall synthesis
41
What is the mode of action for cloxacillin?
Suppression of cell wall synthesis
42
How is cloxacillin administered?
Orally
43
What is the mode of action for augmentin?
Suppression of cell wall synthesis
44
How does augmentin work?
It is combined with a clarulanic acid (the suicide substrate) which binds irreversibly with the active site of penicillinase
45
What is the mode of action for zosyn?
Suppression of cell wall synthesis
46
Zosyn is a DOC for?
Pseudomonas aeruginosa
47
How does Zosyn work?
Combination of pipercillin and tazobactam. The Tazobactam acts as a suicide substrate, binding irreversibly to the active site of penicillinase
48
Name 4 non-penicillin drugs that suppress cell wall synthesis
1. Cephalosporines 2. Carbapenems 3. Bacitracin 4. Vancomycin
49
What are cephalosporines produced by?
A mold of the genus cehpalosporium
50
Chemically, how are cephalosporines different from penicillin
Cephaosporines have two side groups instead of the single side group that penicillin has
51
What are the names of the modified cephalosporines? What generation is each one?
Gen 1 - Cephalothin and Cephalexin (keflex) Gen 2 - Cefotiam Gen 3 - Moxalactam, Cetotaxine, and Ceftriaxone 4. Cefepime
52
What generation of cephalosporines are narrow spectrum, and only active against G+
Gen 1 - Cephalothin and Cephalexin (keflex)
53
What is the mode of action of generation 1 cephalosporines?
Suppression of cell wall synthesis
54
What is the mode of action for generation 2 cephalosporines?
Suppression of cell wall synthesis
55
What is the mode of action for genertion 3 cephalosporines?
Suppression of cell wall synthesis
56
What is the mode of action for generation 4 cephalosporines?
Suppression of cell wall synthesis
57
What are generation 1 (Cephalothin and Cephalexin) used to treat?
I is used to treat patients with staphylococci and streptococci, our used in surgery as a prophylactic
58
Why do cephalosporines make a good penicillin substitute?
Good penicillin substitutes because they are not broken down by penicillinase (but they can be broken down by cephalosporinase), and can be used when the patient is allergic to penicillin
59
What are generation 2 (Cefotiam) cephalosporines used against?
Since they are better at attacking G- bacteria, gen 2 is used against Aterobacter proteus (G-) and hamophilus (G-), as well staph and strept
60
In what generation do cephalosporines become broad specturm?
3rd, with Moxalactam and Cetotaxine and Ceftriaxone
61
Cefepime is a a DOC against what?
Klebsiella pneumonae, which has a capsule making it very resistant
62
Is cefepime broad or narrow spectrum?
Broad
63
Are carbapenems more or less active that 3-4th generation of cephalosporines?
More
64
Primaxin is an example of what?
Carbapenems
65
What is primaxin (chemically)?
Imipenem (a cabepenem) and cilastatin (used to make sure the dipeptidase in your kidney doesn't break down the imipenem)
66
What is Priamin used against?
Genus Acinetobacter, which are commonly super bugs
67
Some strains of klebsiella pneumoniae are consitered superbugs because they contain what enzyme?
carbapenemase
68
Whats does CRE stand for?
Carbapenem resistant enterococci
69
What is the mode of action for carbapenem?
Suppression of cell wall synthesis
70
What is bacitracin isolated from?
Isolated from the bacillus
71
What does bacillus produce in addition to bacitracin?
polymixins (narrow spectrum) and polypeptides (narrow spectrum for G+)
72
Where is bacitracin found?
In triple antibiotics
73
What is in a triple antibiotic?
Polymyxin B (G-Bacitracin (G+) Neomycin (broad)
74
What is the most of action for bacitracin?
Suppression of cell wall synthesis
75
Vancomycin is isolated from what?
Streptomyces
76
Vancomycin is a DOC for what?
MRSA and systemic infections
77
What is the toxicity or vancomycin? How often is it prescribed?
High toxicity, often prescribed, which is resulting in resistant organisms
78
What are the two modes of action for antimetabolites
1. Competitive inhibition 2. pH
79
Define competitive inhibition
Having a structural analogue attack the active site of the enzyme/chemical in question
80
What is the normal pH of cells?
close to 7
81
Are are some antimetabolite agents with competitive inhibition as their mode of action?
1. Sulfonamides 2. Sulfones 3. Isoniazid 4. Trimethoprim 5. PAS (p-aminosaliclic acid) 6. Quinie, chloroquine, primaquine
82
Sulfonamides have what mode of action?
Competitive inhibition
83
Give 5 examples of a sulonamide
1. Sulfanilamide 2. Sulfadiazine 3. Sulfisoxazole 4. Sulfamethoxazole 5. Bactrim PCP
84
Describe sulfanilamide
A type of sulfonamide that is either static or inhibitory, and no longer used today
85
What is sulfadiazine used for?
Burn patients, because it has AgNO3 in it
86
What is sulfisoxazole used for?
Uncomplicated urinary tract infections commonly caued by e.coli and preventing rheumtic fever, which is caused by streptococcus pyrogenes
87
Define uncomplicated urinary tract infection
Not exposed to instrumentation like a catheter, blockage, or antibiotic therapy
88
Suldamethoxazole is combined with what for a synergistic effect? Why?
trimethoprime (bactrim). It works in two places in the PABA pathway
89
Bactrim PCP is used to what?
Prevent pneumonia and treat superficial MRSA
90
Do sulfones use the PABA pathway?
Yes, they react at similar spots of sulfonamides
91
What is an example of a sulfone
Dapsone
92
Dapsone is used as a DOC for what?
Mycobacterium leprae
93
What is another name for Isoniazid?
INH - isonicotinic hydrazide
94
Isoniazid is a DOC for what?
mycobacterium tuberculosis
95
What vitamin does isoniazid resemble?
vitamin B
96
How does isonazid work?
Prevents mycolic acid from being incorporated into the cells walls of the mycobacterium
97
Trimethoprim is a part of what other antibiotic?
Bactrum
98
What makes trimethoprim synergistic
Works at the second point in the PABA pathway
99
PAS stands for what?
p-aminosalicylic acid
100
PAS is a DOC for?
resistant strains of tuberculosis
101
MDR TB stands for what?
Multiple resistant tuberculosis (resistant to both INH and ritampin)
102
XDR TB stands for what?
Extensively/Extremely drug resistant tuberculosis (resistant to INH, ritampin, any foluoroquinolone (ciprofloxicin), plus any injectable aminoglycocides (capreomycine, kanamycine, amikacin))
103
Quinie, chloroquine, and primaquine are used against what disease?
Malaria
104
Quinie, chloroquine, primaquine are isolated from what?
Bark of a cinchona tree
105
How does quinie work?
Quinie makes the food vacuoles of malaria so alkyline that it makes it hard to break down the hemoglobin
106
What is the name of this pathway?
PABA (its on the freaking picture)
107
What drugs act at the first part of the pathway?
Sulfonamides and Sulfones
108
What drugs work on the second part of the pathway?
Trimethoprime
