pharmacology 1st quiz TS Flashcards
(229 cards)
0
Q
which antimicrobial drugs interfere with bacterial cell wall synthesis?
A
beta lactams
bacitracin
vancomycin
cycloserine
1
Q
which antimicrobial drugs act on bacterial cell membrane?
A
polymyxin b
colistin
2
Q
which antimicrobial drugs interfere protein synthesis at 30s subunit?
A
tetracyclines
aminoglycosides
3
Q
which antimicrobial drugs act on 50s subunit?
A
chloramphenicol
macrolides
lincosamides
4
Q
which antimicrobials interfere with nucleic acid synthesis?
A
fluoroquinones
rifampin
metronidazole
5
Q
which antimicrobials interfere with folic acid synthesis?
A
sulfonamides
diaminopyrimidines
6
Q
which antimicrobials are narrow spectrum?
A
beta lactams
aminoglycosides
polymyxin b and colistin
7
Q
which antimicrobials are bacteriostatic?
A
sulfonamides
tetracyclines
chloramphenicol
macrolides and lincosamides
8
Q
what are the 3 efficacy predictors of antimicrobials?
A
type 1 - conc dependent
type. 2 time dependent
type 3 time dependent with pae (persistant suppression of bacteria)
9
Q
what combo of antimicrobials produces additive effect?
A
bacteriostatic
10
Q
what combo of drugs produces synergistic effect?
A
bactericidal drugs
11
Q
what combo of drugs produces antagonistic effect?
A
bactericidal with bacteriostatic
12
Q
what is transduction (antibiotic resistance)?
A
bacteria virus transfers genes
13
Q
how do bacteria get antibiotic resistant from uptake of genes in environment?
A
transformation
14
Q
what ways can bacteria decrease accumulation of drugs inside them?
A
decrease permeability thru cell membrane of gram negatives
energy dependent active efflux of drug
15
Q
what is the prerequisite of folic acid in bacteria?
A
PABA
16
Q
what are the 5 enteric sulfonamides?
A
succinylsulfathiazole sulfasalazine sulfquinoxaline sulfaguanidine phthalylsulfathiazole
17
Q
what does a triple sulfa bolus consist of?
A
sulfinilamide, sulfathiazole, sulfamethazine
18
Q
which sulfonamide is hydrolzyed in the bowl?
A
phthalylsulfqthiazole
19
Q
which sulfonamide is split into 2 parts in intestine and treats dog coilitis?
A
sulfasalazine
20
Q
ehat are the 2 moa of sulfonamides?
A
structural analog of PABA, gets substituted
act as antimetabolites and interfere with rna and dna
21
Q
which. 2 sulfonamides can be used topically?
A
silver sulfadiazine
mafenide
22
Q
which sulfonamide should be used for opthalmic apps because of neutral ph?
A
sulfacetamide
23
Q
how are sulfonamides metabolized?
A
acetylation in liver
24
what effect does alkaline urine have on the excretion of sulfonamides?
increases fraction of dose eliminated in urine
25
what are the 2 immunological based toxicities of sulfonamides?
kcs ( dry eye)
| hepatic necrosis
26
what is the non immunological effects of sulfonamide toxicity on kidney?
crystalluria
hematuria
renal tubular blockage
because of dehydration, keep well hydrated and aciduria protects
27
does a combination of sulpha drugs increase or decrease their solubility?
increase ( law of independent solubility)
28
which sulpha drug causes hypoprothrombinemia in dogs and chickens?
sulfaquinoxaline
29
what sulfa drug can cause aplastic anemia?
trimethoprim sulfadiazine ( potentiated sulfa)
30
which species can have hypoglycemia from taking sulfa drugs?
ducks and dogs
31
which breed of dog can get polyarthritis and hepatitis from sulfa drugs?
doberman pinschers
32
what gland may sulfonamides interfere with but is reversible?
thyroid gland
33
What group is sulfonamides in efficacy predictors?
type 2 antimicrobials, therefore ideal dosing maximizes duration of exposure
34
What type of molecule are diaminopyramidines?
lipid soluble organic bases
35
Are diaminopyramidines bacteriocidal or bacteriostatic?
bacteriostatic
36
How do diaminopyramidines block bacterial folate synthesis?
reversibly binds and inhibits dihydrofolate reductase
37
Which diaminopyramidine inhibits folate synthesis in protozoa?
pyrimethamine
38
Which diaminopyramidine can be given orally to ruminants?
ormetoprim
39
What are the 3 different diaminopyramidines?
Pyrimethamine, trimethoprim, and ormetoprim
40
Are potentiated sulfonamides bacteriostatic or bacteriocidal?
bacteriocidal (each one alone is bacteriostatic)
41
How do beta lactam antibiotics exert bactericidal activity?
interfere with transpeptidase enzyme that is responsible for formation of cross links (penicillin binding proteins - PBP)
42
What type of bacterial cell wall can beta lactams NOT penetrate?
gram negative
43
What 2 beta lactam drugs are "natural penicillins"?
Penicillin G
| Penicillin V
44
Which natural penicilllin can be given orally?
Penicillin V
45
What are the 2 log acting formulations of Penicillin G?
Benzathine
| Procaine
46
What bacteria are resistant to natural penicillins?
Pseudomonas, enterobacteriaceae and penicillinase producing staph
47
What are the 3 groups of semi synthetic penicillins?
```
Penicillinase resistant penicillins
Broad spectrum (aminopenicillins)
extended spectrum (carboxypenicillins)
```
48
What 3 penicillinase-resistant penicillins have good oral absorption?
Cloxacillin
Oxacillin
Dicloxacillin
49
What are penicillinase-resistant penicillins used to treat mostly?
staph infections
| -bovine staph mastitis
50
What penicillinase-resistant penicillin can be formulated as an opthalmic ointment and treat staph and bacillus infections?
cloxacillin
51
What are the two drugs in the broad spectrum penicillins?
Amoxicillin
| ampicillin
52
What are some related esters of ampicillin? (prodrugs)
bacampicillin
hetacillin
pivampicillin
talampicillin
53
What 5 penicillins are in the extended spectrum group?
ticarcillin, carbenicillin, piperacillin, mezlocillin, azlocillin
54
Why can't procaine penicillin G be administered IV?
affects cardiac conduction system
55
What can be used to competitively inhibit penicillin excretion?
another organic acid, such as probenecid
56
Which penicillin is not excreted in urine?
Nafcillin (bile)
57
What can sodium benzylpenicillin produce in dogs and cats?
ataxia and convulsions (inhibits GABA)
58
What drug can produce anaphylaxis and CNS disorders in small mammals and reptiles?
procaine
59
What can procaine and postassium penicillin salts administered IV as a rapid bolus induce?
acute cardiac toxicities
60
What salt form should you use when administering penicillins IV?
sodium salt
61
What are the 3 first generation cephalosporins that can be given orally?
cefadroxil
cephalexin
cephradine
62
What are the 3 first gen cephalosporins that can be given parenteral?
cefazolin
cephalothin
cephapirin
63
Which first gen cephalosporin has greatest gram negative activity?
cefazolin
64
What bacteria are 2nd gen cephalosporins better at killing than 1st gen?
gram negative because increased resistance to lactamases
| also anaerobes
65
Which drug is a "new generation" of cephalosporins?
ceftiofur (broader gram + activity)
66
How does ceftiofur compare to other 3rd gen cephalosporins?
better at strept
| less activity against pseudomonas
67
What cephalosporin is 4th gen?
cefepime
68
Which 2 cephalosporins have the best oral absorption?
cephalexin
| cefaclor
69
What is the only 2nd gen cephalosporin that can penetrate cerebrospinal fluid?
cefuroxime
70
What 3rd generation cephalosprins can attain high concentration in cerebrospinal fluid when meninges are inflammed?
ceftriaxone
cefotaxime
ceftazidime
ceftizoxime
71
What 2 cephalosporins can decrease platelet aggregation?
cephalothin
| cefinetazole
72
How does clavulanic acid and sulbactam potentiate penicillin?
competitive inhibitor of beta lactamases of bacteria
73
What are the two kinds of Cabapenems?
Imipenems
| Meropenems
74
What must imipenems be administered with?
cilastatin (renal enzyme inhibitor)
75
What bacteria does imipenems have activity on?
broad spectrum
gram negative aerobic
anaerobic
76
What is the adverse effect of imipenems?
seizures
77
How is meropenems different from imipenems?
more soluble
| decreased seizures
78
What can be used against gram negative bacteria or pseudomonas if patient is allergic to penicillin?
monobactams
79
How do antimicrobials that inhibit protein synthesis target bacterial ribosomes instead of the host?
affinity for 70s size (eukaryotes is 80s)
80
What 2 parts of protein synthesis can antibiotics interfere with?
initiation
| elongation of polypeptide chain
81
What 2 groups of antibiotics act on the 30 S subunit to inhibit protein synthesis?
aminoglycosides
| tetracyclines
82
What 3 groups of antibiotics act on 50S subunit to inhibit protein synthesis?
macrolides
lincosamides
chloramphenicol and derivatives
83
Are aminoglycosides bacteriostatic or bacteriocidal?
bactericidal
84
What are the 6 aminoglycoside drugs?
```
streptomycin
neomycin
kanamycin
gentamicin
amikacin
tobramycin
```
85
Why is one single dose of aminoglycosides q24 the same as many small ones?
post antibiotic effect (PAE)
86
What kind of bacteria do aminoglycosides act on?
aerobic gram negative bacteria
87
What aminoglycoside has the broadest spectrum?
amikacin
88
Which bacteria has natural permeability barrier to aminoglycosides?
streptococci
89
How are aminoglycosides administered?
parentally (never orally)
90
Where do aminoglycoside drugs concentrate in the body?
perilymph of the inner ear and in the renal cortex (attracted to phospholipids)
91
Why shouldn't aminoglycosides and diuretic agents be used concurrently?
dehydration --> nephrotoxicity
92
What can happen when aminoglycosides are in high plasma concentrations after bolus?
non depolarizing neuromuscular blockade
93
What are 3 ways bacteria can be resistant to aminoglycosides?
enzymatic inactivation
ribosomal alterations
reduced permeability to drug
94
What is the efficacy predictor of aminoglycosides?
Type 1 - concentration dependent killing kinetics
95
How can renal uptake of gentamicin be inhibited?
alkalinizing the urine with sodium bicarbonate
96
Which aminoglycoside is too toxic for systemic use and used in topical applications?
neomycin
97
Which aminoglycoside is effective against gram positive AND negative bacteria?
paromomycin
98
What aminoglycoside is effective against Pseudomonas in dogs and cats?
Tobramycin
99
What are the 3 natural tetracyclines?
chlortetracycline
tetracycline
oxytetracycline
100
What are the 2 semi-synthetic tetracyclines?
minocycline
| doxycycline
101
Are tetracyclines bacteriostatic or bacteriocidal?
bacteriostatic
102
What do tetracyclines bind to?
30s ribosomal subunit
103
Which tetracycline is the treatment of choice for equine monocytic ehrlichiosis? (potomac horse fever)
oxytetracycline
104
What tetracycline is effective against penicillinase resistant strains of staph aureus?
minocycline
105
What microorganisms are resistant to tetracyclines?
Proteus vulgaris
Pseudomonas aeruginosa
Mycobacterium
some Mycoplasma
106
Which tetracycline is given IM?
oxytetracycline
107
Which tetracycline is more completely absorbed in GI tract?
doxycycline
108
What are the 2 most lipid soluble tetracyclines?
Minocycline and doxycycline
109
What two tetracyclines are metabolized in the body? How are they then removed?
mino (oxidation)
| doxy (bile diffusion) - can be used in renal failure
110
Why should IV (oxy?)tetracycline be given slowly?
chelates calcium in blood
111
What can IV injections of doxy in horses do?
induces cardiac arrhythmia -- sudden death
112
How does oral tetracycline alter microflora in horses?
proliferation of clostridium perfringens or salmonella --> colitis
113
What group of efficacy predictors does tetracycline belong to?
type 3 - time dependent killing and PAE
114
What is the mode of action for chloramphenicol?
binds to 50s subunit
115
What can happen in prolonged admin of chloramphenicol?
bone marrow suppression (esp in cats) mitochondrial ribosome similar to bacterial one
116
What other antibiotic can chloramphenicol compete with and should not be administered with?
macrolides (erythromycin)
117
Which 2 types of bacteria are resistant to chloramphenicol?
Pseudomonas aeruginosa
| enterobacteriaceae (readily acquired)
118
Which chloramphenicol drug is only available orally?
chloramphenicol base
119
Which chloramphenicol is hydrolyzed in small intestine by esterases?
chloramphenicol palmitate
120
Which chloramphenicol can be given IV/IM?
chloramphenicol succinate
121
How is chloramphenicol metabolized and therefore which animal has a slower clearance time?
conjugated with glucoronic acid
| cats
122
Can you use chloramphenicol in food-producing animals?
NO!
123
Which chloramphenicols do not induce bone marrow stem cell damage?
thiamphenicol
| florfenicol
124
What type of animals are most sensitive to chloramphenicol toxicity?
young animals
cats
impaired liver fxn
125
What is the side effect in newborn humans that are treated with high doses of chloramphenicol?
Gray baby syndrome
126
Which bacterial enzyme inactivates chloramphenicol and is acquired by plasmids?
acetyltransferase (florfenicol resistant to it)
127
What semi-synthetic chloramphenicol derivative is more water soluble?
thiamphenicol
128
Which chloramphenicol derivative is more potent and can be used in food producing animals?
florfenicol
129
What efficacy predictor group is chloramphenicol?
type 2 - time dependent
130
What are the 6 macrolide antibiotics?
```
erythromycin
tilmicosin
tylosin
tiamulin
azithromycin
clarithromycin
```
131
How do macrolides differ in their mode of action than chloramphenicols?
unable to cross mitochondrial membrane and do not effect bone marrow
132
Are macrolides bacteriostatic or bacteriocidal?
bacteriostatic at therapeutic levels
| bacteriocial slowly against strep
133
How does pH effect the antimicrobial action of macrolides?
high pH - enhanced
| low pH - suppressed
134
Which macrolide is used to treat pink eye?
tiamulin
135
What is the preferred route of admin of macrolides?
oral (injections painful)
136
Which macrolide is metabolized by the liver?
erythromycin
137
Which macrolide is fatal to horses?
tylosin
138
Which macrolide has a type 3 efficacy predictor?
azithromycin
139
What 2 drugs are lincosamides?
lincomycin
| clindamycin
140
What bacteria are not effected by lincomycin?
gram negatives
141
Which lincosamide is more lipid soluble and can cross BBB?
clindamycin
142
How are lincosamides excreted?
bile
143
What animals should lincosamides not be used in?
chinchillas, guinea pigs, hamsters
horses, ponies
rabbits
144
What efficacy predictor group is lincosamides?
type 2
145
What 2 groups of antimicrobials inhibit DNA replication?
fluorquinolones
| metronidazole
146
What antimicrobial drug inhibits RNA synthesis?
rifampin
147
What are the 3 first generation fluorquinolones?
naildixic acid
oxolinic acid
cinoxacin
148
What are the 4 third generation fluoroquinolones?
orbifloxacin
levofloxacin
sparfloxacin
grepafloxacin
149
What are the 7 2nd generation fluorquinolones?
```
ciprofloxacin
enrofloxacin
marbofloxacin
danofloxacin
difloxacin
norfloxacin
enoxacin
```
150
What bacterial enzyme is inhibited by fluoroquinolones?
DNA gyrase enzyme
151
Which fluoroquinolone may have activity on anaerobes?
difloxacin
152
What type of bacteria are more susceptible to fluoroquinolones in an alkaline environment?
Enterobacteriaceae and other gram negative aerobes
153
What three conditions is pradofloxacin effective for against anaerobes, gram positives and gram negatives?
pradofloxacin
154
What are the two "new" generation fluoroquinolones?
premafloxacin
| pradofloxacin
155
What are the 2 factors that affect the action of fluoroquinolones?
Cations decrease activity
| low pH decreases activity
156
Which fluoroquinolones can be given in water for poultry infections?
enrofloxacin
| sarafloxacin
157
Which fluoroquinolone is not widely distributed in tissues?
first
158
Which 2 tissues do fluoroquinolones not achieve a high concentration?
Cns, eye
159
Which fluoroquinolone is well distributed in bone, prostate and skin and all horse tissues?
enrofloxacin
160
What tissue does enrofloxacin, marbofloxacin and orbifloxacin achieve good levels?
prostate
161
Which 2 fluoroquinolones are highly excreted in milk?
enrofloxacin
| danofloxacin
162
Which fluoroquinolones have active metabolites?
Difloxacin
Enrofloxacin
Pefloxacin
163
Which fluoroquinolone exception is excreted through faeces instead of urine?
difloxacin
164
What are some of the side effects of fluoroquinolones?
```
Photosensitivity
CNS effects
Crystalluria
GI effects
Arthropathy/Joint Arthropathy
Ocular toxicities
```
165
What fluoroquinolone causes abnormalities in horses tendon cultures?
enrofloxacin
166
Why does fluoroquinolones given IV rapidly cause CNS effects?
inhibition of GABA
| dont give to seizure patients
167
What is the most important bacterial resistance mechanism for fluoroquinolones?
increased efflux (alterations in gyrase enzyme and decreased uptake also mechanisms)
168
What efficacy group is fluoroquinolones?
Type 1 - max concentration
169
What is the MOA for bacitracin?
inhibits peptidoglycan synthesis
170
What are the indications for bacitracin?
topical tx of superficial infections in skin, mucosal surfaces, ear and eye
171
What is the MOA for novobiocin?
inhibits cell wall synthesis, RNA, DNA, protein, respiration
172
Do bacteria acquire resistance against novobiocin?
Yes, very quickly
173
What spectrum of activity does thiostrepton have? how is it administered?
gram + and some -
| topical therapy
174
Which nitrofuran drug can have a carcinogec effect when administered chronically?
Furazolidone
175
How are nitrofurans administered?
Topically/orally
| need acid environment to go into cell membrane
176
What is the MOA for virginiamycin and is it bacteriostatic or bacteriocidal?
Bacteriocidal
| inhibits protein synthesis at 23s ribosomal subunit
177
What is the clinical use of virginiamycin?
growth promotion in swine, turkeys and laying hens
178
What clinical uses is carbadox used for?
growth promotant in swine
| tx swine dysentery, bacterial enteritis
179
What happens if there is a toxicity of carbadox?
hypoaldosteronism (>100 ppm)
180
What is the MOA for vancomycin? Bacteriocidal or static?
inhibits peptidoglycan synthesis
| bactericidal
181
What should vancomycin be combined with to treat enterococcal infections?
aminoglycoside (amikacin/gentamicin)
182
What are the 2 adverse effects of vancomycin?
nephrotoxicity
| histamine release --> IV
183
What group of antibiotics is vancomycin in that is banned from using in food animals?
glycopeptides
184
Is methenamine bacteriostatic or bacteriocidal
depends on pH of urine
185
What condition is methenamine used to treat?
UTI in small animals
186
What other antibiotic should not be administered with methenamine?
sulfonamides
187
What 2 antibiotics interfere with the cell membrane?
polymyxin B
| colistin (polymyxin E)
188
Are polymyxins bacteriostatic or cidal?
bacteriocidal
189
Why are polymyxins used for "bowel sterilization" before sx?
not absorbed from GIT when given orally
190
What is polymyxin B effective against in gram negative bacteria infections?
endotoxins
191
How are most polymyxins given?
topical use
192
What can polymyxins be combined with to act synergistically against gram negative bacilli?
sulfonamides
193
What is the MOA for metronidazole?
disrupts DNA structure
| bacteriocidal
194
What type of bacteria is metronidazole most effective against?
systemic and enteric obligate anaerobic bacterial infections
195
What part of metronidazole can have a carcinogenic effect in rats?
a minor metabolite that evolved from splitting the metronidazole ring
196
Can nitroimidazoles be used in food producing animals?
NO - may be carcinogenic
197
What efficacy predictor group is metronidazole?
type 1 - concentration dependent
198
How is rifampin metabolized?
de-acetylation --> active metabolite
| induces Cytochrome p450
199
How is rifampin excreted?
bile
200
What are some of the adverse effects of rifampin?
anemia/thrombocytopenia
| hepatitis in dogs
201
what are the 5 bacteiostatic type drug groups?
```
sulfonamides
tetracyclines
chloramphenicol
macrolides
lincosamides
```
202
Which antibiotic causes bowel sterilization?
Polymyxin
203
What is it called when 2 static antibiotics work together?
additive effect
204
What group of antibiotics is effected by cations and pH?
fluoroquinolones
205
What cephalosporin is the only 2nd gen that can go into CSF?
cefuroxime
206
What antibiotic treats swine dysentery but has hypoaldosteronism toxicity?
carbadox
207
What are the antibiotics that are type 1 efficacy? (3)
aminoglycosides
fluoroquinolones
metronidazole
208
What are the 5 bacteriostatic antibiotics?
sulfonamides
tetracyclines
chloramphenicol, macrolides, lincosamides (50S)
209
Which beta lactam has low immunogenic profile?
monobactam (aztreonam)
210
Which cephalosporins are excreted in bile?
ceftriaxone
| cefoperazone
211
Which bacteria are resistant to fluoroquinolones?
anaerobes
212
What is the first choice antibiotic for C. jejuni?
Erythromycin
213
What is the first choice drug for mycoplasma sp?
tiamulin
214
What bacteria are susceptible to metronidazole?
```
obligate anaerobes (clostridium, fusobacterium)
protozoa
```
215
Which antibiotics are carcinogenic?
Metronidazole
| Nitrofuran
216
Which antibiotic has good effect on pseudomonas and proteus?
Polymyxin
217
Which drug group has arthropies and ocular toxicities?
fluoroquinolones
218
What bacteria are resistant to lincomycin?
gram negatives
219
What are the susceptible bacteria groups of each of the cephalosporin generations?
First - gram +
2nd - gram -
3rd - better gram -
Ceftiofur - more gram +
220
Which drug group chelates calcium in teeth and bone?
tetracyclines
221
What is the 4th generation cephalosporin?
cefepime
222
Which drug group causes fatal enterocolitis in hind gut fermenters?
lincosamides
223
What are the 4 antibiotic groups banned in food animals?
Metronidazole
Vancomycin
Nitrofurans (Furazolidone)
Chloramphenicol
224
Which antibiotics inhibit GABA?
Fluoroquinolones
| Penicillin
225
What drug is combined with tetracycline for synergism against kennel cough?
novobiocin
226
Which antibiotics treat prostate infection?
Enrofloxacin
marbofloxacin
orbifloxacin
(fluoroquinolones)
227
Which macrolide causes cardio toxicity?
tilmicosin
228
How is bacterial resistance acquired against rifampin?
single step mutation --> happens quickly
| use with other antimicrobials
