Block 6 Flashcards
(140 cards)
1
Q
What type of antibiotic is penecillin?
A
Beta Lactam
2
Q
What is a cephalosporin?
A
Beta lactam
3
Q
What type of antibiotic are beta lactams?
A
Time-dependent bactericidal
3
Q
What does a time dependent dosing frequency mean?
A
Need to dose often
4
Q
Are beta lactams time or concentration dependent?
A
Time!
5
Q
What makes a beta lactam a beta lactam?
A
The beta ring that forms
6
Q
General rule: Keep abx concentration above MIC for ________ of dosing interval
A
50%
7
Q
How does the MOA work?
A
Beta lactams bind the penicillin-binding proteins cause the cell wall instability
8
Q
What is the mechansim of action of beta lactams?
A
Inhibits bacterial cell wall synthesis
Disrupts cell wall integrity
9
Q
What is the mechansim of resistance of beta lactams?
A
Hydrolyze the beta-lactam ring
10
Q
What is a beta-lactamase inhibitor?
A
It is a drug that works alongside beta lactams to prevent the drug from being inactivated
11
Q
What are 3 beta lactamase inhibitors?
A
clavulanate acid, tazobactam, and sulbactam
12
Q
What bacteria produce the beta lactamases that inactivate beta lactams?
A
Gram + - staph
Gram - - enterobacterales
13
Q
What does ESBLs stand for?
A
Extended-spectrum beta-lactamases
14
Q
What do ESBLs act upon?
A
Hydrolyses penicillins, monobactams, and 1st, 2nd, 3rd, and 4th generation cephalosporins
15
Q
What is a secondary mechanism of resistance of beta lactams?
A
Altering the binding site of the penecillin binding protein (PMP)
16
Q
Which bacteria have a modified PMP?
A
Methicillin-resistant staphylococci (MRSP and MRSA)
17
Q
What does the altered PMP confer resistance to?
A
Penecillins, cephalosporing, and carbapenems
18
Q
What is the exception to the PMPs for cephalosporins?
A
5th generation cephalosporins
19
Q
What is the 3rd mechanism of resistance of beta lactams?
A
Decreased penetration
Block entry
Increase efflux to pump them out
20
Q
What bacteria type is this mechanism of resistance mostly seen in/?
A
Gram -
21
Q
How do you never administer Penecillin G?
A
IV NEVER!
22
Q
Why is penecillin not absorbed orally?
A
Inactivated in low pH
23
Q
How is amoxicillin/ampicillin given?
A
Oral, IM, or IV
24
Where are penecillin concentrations highest?
Kidneys, synovial fluid, liver, lung, skin, soft tissues
25
How are penecillins metabolized?
Hydrolysis of beta lactam ring
26
Does penecillin penetrate the BBB?
No
27
How is penehat is half life of penecillin?
0.5-1 hour
28
How is penecillin eliminated?
Urine (kidneys)
29
Do penecillins work on MRSA?
No
30
What are the 3 penecillin/beta lactamase combos used?
Ampicillin / sulbactam (unasyn)
Amoxacillin / clavulamic acid (clavamox)
Piperacillin / Tazobactam
31
Oral penecillins cause serious / fatal diarrhea in horses
32
What are 3 adverse side effects of penecillin?
GI (V, D, inappetance)
Hypersensitivity
Pain or tissue rxn
33
How are cephalosporins given?
Oral or parental
34
Which generation of cephalosporins penetrate the CNS?
Gen 3
35
What is half life of cephalosporins?
1-2 hrs
36
How are cephalosporins metabolized?
Renally
37
What is a general rule about the generations of cephalosporins?
Higher the generation, higher the Gram - coverage
38
What is teh exception to the above rule?
Gen 5 (MRSA coverage)
39
What is 1st gen oral?
Cephalexin, cefadroxil
40
What is 1st gen parental?
Cefazolin
41
What is 3rd gen oral?
Cefpodoxime
42
What is 3rd gen parental (long acting)?
cefovecin
43
What is 2nd and 3rd gen parental?
cefoxitin (2), ceftiofur (3), cefotaxime(3), ceftazidime(3)
44
What are the adverse affects of cephalosporins?
Same as penecillin
45
*****What bacteria class are intrinsically resistant to cephalosporins?
Enterococci on exam!
46
What do 1st gen cover?
Great Gram + coverage
Strep and Staph
Good for UTIs and skin infections
47
How is absorption of cephalexin and cefadroxil (1st gen) in horses and ruminants?
Low
48
What 1st gen is used in farm animals?
Cephapirin
49
What does cephapirin treat in farm animals?
Mastitis for intrmammary infusions
49
When do you use anything above 1st gen cephalosporins?
When there is resistance to 1st gens
50
When is 2nd gen cefoxitin and cefotetan good?
Septic peritonitis (anaerobic)
51
What is simplicef?
3rd gen cefpodoxine
52
What is Convenia?
Cefvecin 3rd gen
53
What is Convenia used for?
UTIs, skin and soft-tissue infections
54
What is ceftiofur?
3rd gen
55
What is ceftiofur used for?
Respiratory infxns in farm animal
56
What is the only way to administer carbapenems?
IV
56
What are the 2 carbapenems used in vet med?
Imipenem
Meropenem
56
What are carbapenems?
Last resort antibiotics
57
What are carbapenems reserved for?
Multidrug resistant infections
58
What are Methicillin-resistant Staph resistant to?
All cephalosporins EXCEPT 5th gen!!
58
What are enterococcus resistant to?
cephalosporins
58
Strep are susceptible to _____ beta-lactams
ALL
59
How to lincosamides act?
Bacteriostatic time dependent!
59
What is the most widely used antimicrobial?
BEta lactams
59
What was lincomycin isolated from?
Streptomyces
60
Beta lactams are bactericidal and time dependent
61
What are the 3 categories of lincosamides?
lincomycin
clindamycin (mostly food animal)
pirlimycin
62
Is lincomycin affected by food intake
Yes
62
In terms of distribution where are therapeutic levels achieved?
Synovial fluid, bile, pleural fluid, peritoneal fluid, skin
62
Is clindamycin or lincomycin better absorbed in GI?
Clindamycin
62
How are lincosamides absorbed?
Oral and parental
63
Is clindamycin affected by food intake?
No
63
How are they excreted?
Through bile, urine, and feces
63
Where are they metabolized?
In the liver
63
Do lincosamides enter the brain?
Roughly 40% penetration
63
What is teh mechansim of action of lincosamides?
Binding of 50s ribosomal subunit
Prevents peptide synthesis, similar to macrolides
64
What are constitutive resistance (MLSBc)?
Bacteria that show high-level resistance to all MLSB antibiotics
64
What are inducible cross-resistance (MLSBi)?
Bacteria resistat to macrolides but initially fully susceptible to clindamycine (lincosamides)
65
What are MLSB antibitoics?
Those that act on teh 50s ribosome subunit
65
What is the mechanism of resistance?
Alter the binding site
66
What are the 2 types of resistance?
Constitutive resistance
Inducible cross-resistance
66
What must be done if during the antibiotic susceptibility test clindamycin is susceptible but erythromycin is resistant ?
A D -test (inducible cross-resistance)
67
What is the gene that causes resistance?
erm gene
68
Are lincosamide broad spectrum?
Yes
Gram - usually resistant
69
What does pirlimycin have an FDA label for?
Staph and strep for INTRAmammary infusion
clinical and subclinical mastitis
70
Is lincosamide a broad spectrum?
Moderate-broad
71
What animals are lincomycin labeled for?
Swine, honeybees, dogs, and cats
72
What can linco treat in pigs?
Erysipelas (penecillin G is best tho I think
73
What can linco treat in chickens?
Pododermatitis - bublefoot - (staph)
74
What can linco treat in honeybees?
American foulbrood
Paenibacillus (USDA monitored disease)
75
Why is clindamycin better?
Better absorbed, more active, and less toxic than linco
76
What does clindamycin treat?
Skin and dental infections
77
What should you avoid the use of lincosamydes on?
Enterococcus
ALL GRAM - and Campylobacter
- Enterobacterales
-pseudomonas aeruginosa
-pasteutella
-bordetella
78
What are side effects of clindamycine?
Fatal diarrhea in horses, rabbits, and other herbivores
79
What happens in cats with clindamycine?
Esophageal strictures
80
Like linocosamides, macrolides are what?
Bacteriostatic and time dependent
81
How do you administer macrolides?
ORAL and parenteral
82
Do macrolides cross the BBB?
No
83
For macrolides, tissue concentration can be higher than serum
84
Do macrolides cross the placenta?
Yes
85
Where are macrolides metabolized?
Liver
86
What is the mechanism of action for macrolides/
Binding of 50s ribosomal subunit
87
What enzyme is responsible for the methylation of adenine?
erm
88
What is the mechanism of resistance for macrolides?
Enzymatic inactivation
89
What is a Gram + macrolide that is a use?
***Rhodococcus equi
90
What are Gram - that macrolides work on?
Bovine respiratory complex (Mannheimia, Pasteurella, Haemophilus) and Bordatella
91
What is a good antibiotic for mycoplasma and bordetella
Azithromycin
92
What is a good antibiotic for Bovine respiratory disase, mastitis, and foot rot?
Tulathromycin
Tilmicosin
Erythromycin
93
What are good antibiotics for equines for rhodococcus equi, strep equi, lawsonia?
Azithromycin
Clarithromycin
Erythromycin
94
What is a good antibiotic to treat swine respiratory diseases?
Tulathromycin
95
What is ineffective in treating mycoplasma and chlamydophila in cats?
Azithromycin
96
Do not use macrolides on enterococcus
97
What bacteria are resistent to macrolides?
Enterobacterales (E. Coli, Klebsiella)
Pseudomonas aeruginosa
98
Should macrolides be used in horses, rabbits, and other small mammals?
No - used in foals
99
What percent of veterinarians were aware of opioid misuse by a staff member or client?
44%
100
Has gabapentin been described to demonstrate analgesic efficacy in cat's joints?
No!
101
Opioid prescription has increase ____ in vet hospitals?
41.2%
102
The number of vet patients with controlled substance prescriptions from 4 or more vets more than _______ from 2024-2019
Tripled
103
How do you treat staph?
First gen cephalosporin
104
How do you treat strep?
First gen cephalosporin or amoxacillin
105
What can oxytet not be used on?
Lactating dairy cows
106
In addition to beta lactams
Macrolides and lincosamides what are 3 more antibiotic categories?
Tetracyclines
Phenicols
Aminoglycosides
107
What are tetracyclines?
Broad spectrum, bacteriostatic, time dependent
108
What additional things can tetracyclines treat?
Blood borne pathogens
109
What is something in dogs that oxytet can treat?
Salmon poinsoning (Neorickettsia helminthoeca)
110
Can you use oxytet in nonlactating dairy cows
Yes!
111
What are the 3 types of tetracyclines?
Oxytet
Doxy
Mynocycline
112
Shoud you use doxy for UTIs?
no
113
What are 2 things that are intrinsically resistant to tetracyclines?
Pseudomonas aeruginosa
Proteus mirabilis
114
Is E. coli resistant?
Mostly, yes
115
What are 3 adverse side effects of tetracyclines?
Nephrotoxic
Yellowing of teeth
Esophageal stricture in cats
116
What are the 2 types of phenicols?
Chloramphenicol and florfenicol
117
What are the characteristics of phenicols?
Bacteriocidal/bactericidal and time dependent
118
Do phenicols cross the BBB?
Yes!
119
What can you not use chloramephenicols in?
Food animal!!!
120
What can you use flofenicol in for cattle?
BRD
Foot rot
121
What can chloramphenicols cause in humans?
Aplastic anemia
122
