antibiotics 1 Flashcards
(74 cards)
1
Q
provides structural integrity of the cell wall
A
Peptidoglycan (PG) layer
2
Q
found in the periplasmic space function to crosslink the peptidoglycan chains
A
Transpeptidase Enzymes
3
Q
what are the 4 bacterial targets
A
cell membrane
cell wall
NA synthesis
protein synthesis
4
Q
4 abx that affect beta lactams
A
- penicillins
- cephalosporins
- carbapenems
- monobactams
5
Q
PCN-G
A
natural PCN
6
Q
PCN-V
A
natural PCN
7
Q
methicillin
A
anti-staphylococcal PCN
8
Q
dicloxacillin
A
anti-staphylococcal PCN
9
Q
nafcillin
A
anti-staphylococcal PCN
10
Q
oxacillin
A
anti-staphylococcal PCN
11
Q
amoxicillin
A
aminopenicillin
12
Q
ampicillin
A
aminopenicillin
13
Q
piperacillin/tazobactam
A
Extended-spectrum (PCN’s + BLI combo)
14
Q
amoxicillin/clavulanate
A
Extended-spectrum (PCN’s + BLI combo)
15
Q
ampicillin/sulbactam
A
Extended-spectrum (PCN’s + BLI combo)
16
Q
aztreonam
A
monobactam
17
Q
imipenem
A
carbapenems
18
Q
meropenem
A
carbapenems
19
Q
ertapenem
A
carbapenems
20
Q
doripenem
A
carbapenems
21
Q
MOA of beta-lactam Abx
A
Inhibit Bacterial Cell Wall Synthesis
1. Drug binds to transpeptidase (aka Penicillin-Binding Proteins [PBP’s])
2. This inhibits bacterial peptidoglycan synthesis preventing bacterial replication (Bacteriostatic)
3. Binding to PBP activates bacterial autolytic enzymes that cause cell wall lysis (Bactericidal)
22
Q
5 methods of resistance for beta-lactams
A
- Beta-Lactamase inactivates drug
- β-Lactamases are a large family of hydrolases that catalyze the hydrolysis of the amide bond in the β-lactam ring of penicillins and cephalosporins. - Increased number of beta-lactamases
- Decreased PBP binding affinity for drug - PCP mutation (“MRSA”)
- Diminished cell wall permeability with a loss of porins - (Gram -)
- Development of efflux pump
23
Q
what must we do about abx resistances
A
- We MUST be careful in antibiotic selection and use
- We MUST educate patients on completion of antibiotic
24
Q
spectrum of natural PCN
A
- g+
- Streptococcus pneumoniae
- some staphylococcus
- bacillus anthracis
- anaerobes (Clostridium perfringens) - g-
- Neisseria meningitides - spirochetes (Treponema pallidum)
25
natural PCN is first line treatment for ?
1. Strep Throat
- Group A Beta-Hemolytic Streptococcus
2. Syphilis
- Treponema pallidum
cellulitis, meningitis
26
pros and cons of natural PCN
- Cons
1. Susceptible to hydrolysis by beta lactamase
2. Resistance increasing
- Pros
1. Cheap
2. Relatively safe
27
susceptibility/indications to use antistaphylococcal PCN
1. Susceptible to B-lactamase
- Not effective against MRSA infections
2. Only indicated in the treatment of skin and soft tissue staphylococcal infections**
- Staph aureus and Staph epidermidis
28
Susceptibility/Indications for aminopenicillins
Same as natural PCN, with better g- coverage
29
aminoPCN first line treatment
(Amoxicillin)
1. Otitis media
- Haemophilus influenzae
- Streptococcus pneumoniae
- Moraxella catarrhalis
2. Prophylaxis for endocarditis
30
using aminoPCN alone makes pts more susceptible to ____. combo forms with ____ available
beta lactamase
BLi
31
2 advantages of aminoPCN over natural PCN
1. higher oral absorption = less frequent dosing
2. better g- penetration thru cell wall porins = superior g- coverage
32
amoxicillin/clavulanic acid
PCN/BLi
augmentin
33
ampicillin/sulbactam
PCN/BLi
unasyn
34
spectrum of PCN/BLi
same as amoxicillin but better staph coverage
(better g-, pseudomonas, anaerobes)
35
first line treatment for sinusitis, pneumonia/COPD exacerbations
PCN/BLi (augmentin)
- s. pneumo
- h. flu
- s. aureus
often reserved for more severe or refractory infections
36
piperacillin/tazobactam
extended spectrum PCN - antipseudomonal PCN
37
spectrum of extended spectrum penicillins
same as PCN PLUS increased g- including
- pseudomonas*
- proteus*
*piperacillin = pseudomonas*
38
indications for antipseudomonal
severe infections
39
cephalexin
1st gen cephalo
40
cefazolin
1st gen cephalo
41
cefadroxil
1st gen cephalo
42
cefuroxime
2nd gen cephalo
43
cefoxitin
2nd gen cephalo
44
cefotetan
2nd gen cephalo
45
cefaclor
2nd gen cephlo
46
cefprozil
2nd gen cephalo
47
ceftriaxone
3rd gen cephalo
48
cefdinir
3rd gen cephalo
49
cefixime
3rd gen cephalo
50
ceftaroline
5th gen cephalo
51
greater cephalo generation = ? coverage
lower cephalo generation = ? coverage
better g-
better g+
52
which abx is safe in pregnancy for simple UTI/cystitis
cephalexin
53
what beta lactam has indications for surgicial prophylaxis and serious MSSA infections
cefazolin (1st gen)
54
what cephalos have better g- that is commonly used as surgical prophylaxis for vaginal and colorectal procedures?
cefoxitin/cefotetan (2nd)
55
what abx are often used for 2nd line pharyngitis, sinusitis, OM, upper and lower rsp tract infections
cefuroxime, cefaclor, cefprozil (2nd gen)
56
what abx is first line treatment for Neisseria gonorrhoeae
ceftriaxone
57
indications for ceftriaxone (4)
1. N. gonorrhoeae*
2. pneumococcal coverage*
3. abd surgical prophylaxis
4. meningitis* - can cross BBB
58
what is the second line treatment for upper and lower rsp tract infections (2)
3rd gen cephalo - cefdinir, cefixime
59
indications for 4th gen cephalo
cefepime - severe infections, meningitis - penetrates CSF very well
pseudomonas*
60
what is the only beta lactam with MRSA and VRE coverage
5th gen cephalo - ceftaroline
61
spectrum of monobactams
g- only
pseudomonas
NO G+ OR ANAEROBES
62
Indications for monobactams
severe infections:
- UTI
- bacteremia/sepsis
- inhalation* - CF, rsp infections
63
imipenem/cilastatin
carbapenems
64
what is the importance of adding cilastatin to imipenem
prevents inactivation in renal tubule
65
spectrum of carbapenems
very broad
- g+, g-, anaerobes
- pseudomonas
- susceptible to beta lactamase - not indicated for MRSA
66
indications for carbapenems
severe infections
- UTI
- meningitis
- chronic DM wounds
- osteomyelitis
- peritonitis/intra-abd infections
67
what is the most common SE of beta-lactams
GI - N/V/D
more likely with amoxicillin/clavulanate and higher gen cephalo
68
may need dosage adjustment for beta lactams with...
renal impairment
69
drug interactions with beta lactams
minimal but can decrease effectiveness of oral contraceptives
70
what beta lactams cover pseudomonas
1. piperacillin/tazobactam (ESP)
2. Ceftazidime (3rd)
3. cefepime (4th)
4. aztreonam (monobactam)
5. meropenem (carbepenem)
6. doripenem (carbepenem)
7. imipenem (Carbapenem)
71
what carbapenem does not cover pseudomonas
ertapenem
72
aztreonam
monobactam
73
what beta lactams have anaerobic coverage
1. PCN (g+)
2. AminoPCN (g+)
3. PCN/BLi
4. cefotetan (2nd)
5. cefoxitin (2nd)
6. carbapenems
74
cefepime
4th cephalo
