Antibiotics Flashcards

1
Q

Name the beta lactams

A

Penicillins, cephalosporins, monobactams, carbapenems

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Penicillins, cephalosporins, monobactams, and carbapenems are what type of agents

A

Beta lactams

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the mechanism of B lactams

A

irreversibly inhibit peptidoglycan polymers in cell wall to cause them to burst, inhibit penicillin binding proteins whch are enzymes that form cross links in membranes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Are beta lactams time or concentration dependent

A

Time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What type of organism do beta lactams work best on

A

G+

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How are most B lactams absorbed

A

Orally then rapidly distributed to ECF

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What type of clearance do B lactams have?

A

Kidney

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Do B lactams cross the BBB

A

No (Except in inflammation)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Are B lactams bound to plasma proteins

A

Not much

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the three mechanisms of resistance to beta lactams

A
  1. b lactamase production via mutation or insertion
  2. change structure of PBPs
  3. Chance lack of penetration thru memb pores
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the 5 subgroups of penicillins

A
Natural
b-lactamase resistant
aminopenicillins
extended spectrum
augmented
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What type of animals are natural penicillins mainly used in

A

Large animal (horses and intra-mammary in food animal)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How should natural penicillins be given

A

IM - NOT ORALLY because acid-labile

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Are natural penicillins degraded by b-lactamase

A

YES!

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What concerns are there for natural penicillin use

A

Long acting can cause residues in food animals, can cause CNS signs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What orgs do natural penicillins kill

A

G+ and G- (anaerobes only)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is a drawback of B-lactamase resistant penicillins?

A

Narrower spectrum - confirm sensitivity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the first line of drugs for treatment in small animals

A

Aminopenicillins (amoxicillan/ampicillan)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are the routes of administration of Aminopenicillins

A

Oral (amoxicillan), IV/IM (ampicillan)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are the side effects of Aminopenicillins

A

GI flora disruption - nausea and V

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are the three classes of penicillins which are most broad spectrum

A

aminopenicillins, extended spectrum, augmented

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What benefit exists in extended spectrum penicillins?

A

Improved Q3 (G- aer), especially pseudomonas! (IV use)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Are extended spectrum penicillins susceptible to b-l’ase?

A

Yes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Describe augmented penicillins

A

Combination of broad spectrum agent + b-l’ase inhibitor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is the toxicity for augmented penicillins

A

GI toxicity in horses, rabbits, hamsters and guinea pigs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What type of effect do penicillins have on orgs

A

Bacteriocidal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What type of antibiotic are cephalosporins

A

B-lactam

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What is the mechanism of action of cephalosporins

A

bacteriocidal cell wall inhibitors via PBP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Are cephalosporins time or conc dependent

A

Time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What is the form of excretion for cephalosporins

A

Renal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What cautions exist for cephalosporins

A

Can be cross reactive in penicillin sensitive animals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Are cephalosporins protein bound

A

No

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Describe cephalosporin generations

A

Go in sequence of oldest to youngest, newer have better gram negative coverage and better resistance to b-l’ase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What spectrum do 1st generation cephalosporins cover

A

Q1 and Q2, some Q3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What type of drug is cefazolin

A

First generation cephalosporin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What kind of drug is cephalexin

A

1-cephalosporin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What is the first line of use cephalosporin in SA

A

1-gen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What spectrum do 2nd generation cephalosporins cover

A

Same as 1-gen but with greater Q3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Do 2-cephalosporins cover pseudomonas?

A

No

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Do 1-cephalosporins cover pseudomonas?

A

No

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What spectrum do 3rd generation cephalosporins cover

A

Q1 and 2 with better gram negative than 2-gen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

What kind of antibiotic is cefpodoxime

A

3-cephalosporin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Name a 1-cephalosporin

A

Cephalexin, cefazolin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

Name a 2-cephalosporin

A

Cephoxitin, cefotetan

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

Name a 3-cephalosporin

A

ceftiofur, cefpodoxime

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

What species is cephalexin approved in

A

Dogs only

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

What Rx should treat bacterial pyoderma

A

cephalexin (1-cephalosporin_

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

What method of admin should be used for 3-cephalosporins

A

parenteral depending on species

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

Restrictions on 1-gen cephalosporins

A

Food animals now may use- major use must follow route/dose/freq restrictions (no ELDU), minor ok to use

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

What are the toxicities of cephalosporins

A

Cross hypersensitivity with penicillins, GI upset (give with meal), chronic use causing overgrowth of candida/pseudomonas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

What kind of agent is Imipenem?

A

Beta lactam from carbapenem class

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

What spectrum does Imipenem have

A

anaerobes and gram + aerobes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

What mechanism of action does bacitracin have

A

Cell wall inhibitor by inhibiting phosphorylation (like vancomycin)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

What organisms are killed by bacitracin

A

G+

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

What mechanism of action does vancomycin have

A

Cell wall inhibitor by inhibiting phosphorylation (like bacitracin)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

What is the method of administration for vancomycin

A

IV (po for GI issues)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

How is vancomycin excreted

A

Renally

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

What are the toxicities of vancomycin

A

Ototoxic, nephrotoxic, tissue irritant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

What are the restritions on vancomycin?

A

NO food animal use, last resort for MRSA in dogs

60
Q

What mech of action does polymixin have

A

Cell wall inhibitor via detergent like action

61
Q

What kind of organisms are killed by polymixin

A

Gram neg

62
Q

Why are penicillins used for UTI

A

High urine concentration due to clearance

63
Q

What type of agents are aminoglycosides

A

Bacteriocidal

64
Q

What are two examples of aminoglycosides

A

Amikacin and gentamycin

65
Q

Are aminoglycosides time or conc dependent

A

Concentration

66
Q

Describe aminoglycosides

A

Highly water soluble, positively charged at bio pH, not lipophilic, low body distribution

67
Q

What is the mechanism of aminoglycosides

A

Irreversible inhibition of protein synthesis via binding to 30S subunit of ribosome which is lethal to most bacteria

68
Q

What is the route of administration for aminoglycosides

A

IV/IM because not orally absorbed (used PO in gastroenteritis)

69
Q

Where are aminoglycosides distributed

A

ECF- not intracellular, accumulates in renal cortex and inner ear

70
Q

What is the elimination of aminoglycosides

A

renal

71
Q

What are the toxicities for aminoglycosides

A

With long term use:
Nephrotoxic- necrosis of tubules
Ototoxic- can be irreversible
Neuromuscular weakness, anaphylaxis

72
Q

Describe aminoglycoside resistance

A

Usually limited to a few drugs, not the whole group; enhanced enzyme degradation, decreased membrane transport, altered ribosome binding site

73
Q

What is unique about how aminoglycosides enter organisms

A

Must be transported by an energy requiring transporter that requires oxygen

74
Q

What are the contraindications of aminoglycosides

A

renal disease, pregnant, fever, myasthenia gravis, neuromuscular disorders

75
Q

What are pseudomonas most susceptible to?

A

Quinolones and aminoglycocides

76
Q

What kind of organisms are most sensitive to aminoglycosides

A
Gram negatives (esp. aerobic like pseudomonas)
(a few G+ orgs- staph!)
77
Q

What drug are aminoglycosides synergistic with

A

B-lactams

78
Q

What kind of drug is gentamycin

A

aminoglycocide

79
Q

What kind of drug is amikacin

A

Aminoglycocide

80
Q

What kind of effect do tetracyclines have

A

Bacteriostatic

81
Q

What is the mechanism of tetracyclines

A

reversible inhibition of protein synthesis by 30S ribosome

82
Q

How do tetracyclines enter an organism

A

Transporter via active transport (determines spectrum of activity)

83
Q

Are tetracyclines acid or base?

A

Amphoteric- both acid and base

84
Q

Name an amphoteric abx

A

tetracyclines

85
Q

How are tetracyclines subclassified?

A

Duration of action

86
Q

What makes a tetracyclines short or fast acting

A

Short: H20 soluble
Long: lipid soluble

87
Q

Name two examples of tetracyclines

A

Doxycyclin, oxytetracyclin

88
Q

What kind of organisms are killed by tetracyclines

A

Gram +, GrNeg Anaer, mycoplasmas, rickettsials and spirochetes

89
Q

What are the mechanisms of resistance for tetracyclines

A

ALtered bacterial transporter, active excretion via pump, enzymatic degradation

90
Q

What abx do tetracyclines show cross resistance with

A

Aminoglycosides and sulfonamides

91
Q

Are tetracyclines protein bound?

A

Yes- some highly

92
Q

What is the best route of administration for tetracyclines

A

Oral- well absorbed - food reduces absorption

93
Q

What is the excretion of tetracyclines? Name exceptions

A

Renal except doxy (hepatic

94
Q

Describe tetracyclines’ toxicity

A

GI, superinfections, ruminal dysfunction, photosensitizing, IM pain/swelling, IV arryhthmias, teeth/bone discoloration in young, hypersensitivity, (expired: nephrotoxic)

95
Q

What restrictions should be used in tetracyclines

A

Pregnant animals; (remember drug interactions

96
Q

Name interactions for tetracyclines

A

Muscle relaxants, food, antacids (oral), IV fluids, loop diuretics, toxic digoxin

97
Q

What species cant use doxycycline

A

LA (use in dog/cat)

98
Q

What species cant use oxytetracyclines

A

Dog/cat (use in beef and non-lactating dairy cattle)

99
Q

What special actions mst be taken in administration of tetracyclines

A

Cats- must follow with water- can cause strictureI

100
Q

What class of tetracycline is doxy

A

Long acting

101
Q

What class of tetracyclines is oxytetra

A

intermediate acting

102
Q

What route should doxy be given?

A

IM or SC

103
Q

What is the drug of choice for erilchia

A

Doxy

104
Q

Is doxy lipo or water philic/

A

lipo

105
Q

What are side effects of oxytetracycline

A

diarrhea and shock in horses

106
Q

Describe macrolides

A

highly lipid soluble (hard to get rid of), all contain a lactone ring

107
Q

What is the mechanism of action for macrolides

A

Bacteriostatic - Reversible inhibition of ribosome protein synthesis in 50S

108
Q

What kind of organisms are sensitive to macrolides

A

Gram +, few gram neg, intracellular orgs like rickettsials and mycoplasma

109
Q

Do macrolides cross BBB

A

No

110
Q

Elimination of macrolides

A

liver, biliary

111
Q

What are the toxic effects of macrolides

A

Major GI,

112
Q

What restrictions should be used in macrolides

A

Caution of colitis and D in horses, guinea pigs, rabbits. Rectal swelling in sheep

113
Q

Describe the resistance of macrolides

A

Alteration of ribosome binding sites

114
Q

What are the drug interactions for macrolides

A

May precipitate and decrease efficacy by binding with many drugs, prolongs effect of warfarin, elevates digoxin levels in dogs

115
Q

What kind of drug is clindamycin

A

Macrolide

116
Q

What kind of drug is azithromycin

A

Macrolide

117
Q

What kind of drug is tylosin

A

Macrolide

118
Q

What is an advantage of azithromycin

A

Less GI effects

119
Q

What drug is best for toxoplasma and resistant R. equi

A

Macrolides

120
Q

Describe the resistance to chloramphenicol

A

Readily transmitted plasmid

121
Q

What is the MOA of chloramphenicol

A

Reversible inhibition of 50S protein synthesis

122
Q

Does chloramphenicol cross the BBB

A

Yes

123
Q

What is the elimination of chloramphenicol

A

Hepatic

124
Q

Toxicitiy- chloramphenicol

A

Human toxicity- major concern
GI disturbances esp. cats
Reduced liver metabolism and diminished clearance
Irreversible bone marrow suppression (aplastic anemia) in humans and dogs

125
Q

Restrictions- chloramphenicol

A

NO food animals

126
Q

What is florfenicol

A

Synthetic derivative of chloramphenicol that is allowed in food animals

127
Q

How are sulfonamides classified

A

Water solubility, duration and tissue distribution

128
Q

What are the side effects of sulfonamides

A

keratoconjunctivitis sicca, IMHA, renal crystallization

129
Q

What is the MOA of sulfonamides

A

Interference with folic acid synthesis in DNA synthesis

130
Q

Sulfonamides- bacterio-

A

static at ther. levels

131
Q

What orgs killed by sulfonamides

A

Gram neg and pos, not good in anaerobes nor pseudomonas

132
Q

What two drugs are not good treating abscesses

A

Sulfonamides and aminoglycocides

133
Q

Describe resistance in sulfonamides

A

High cross resistance, diverse mechanisms

134
Q

Elimination- sulfonamides

A

kidney and liver

135
Q

What are the drug interactions of sulfonamides

A

Disrupted protein binding and renal tubular secretion with many drugs, antagonized by PABA, oral antacids reduce absorption

136
Q

What is the newest group of antibiotics

A

Fluoroquinolones

137
Q

What kind of drugs are similar to fluoroquinolones

A

Weak organic acids- penicillins, cephalosporins, sulfas

138
Q

Time or conc- Fluoroquinolones

A

Concentration

139
Q

MOA- Fluoroquinolones

A

Inhibit bacterial DNA gyrase (topoisomerase II) to block DNA transcription

140
Q

What drugs are good for respiratory tract?

A

Fluoroquinolones

141
Q

What is the spectrum for Fluoroquinolones

A

Broad Gram neg and aerobes

142
Q

QRDR

A

Quinolone resistance determining region-

143
Q

What is the excretion of Fluoroquinolones

A

Hepatic and renal

144
Q

Better FQ in dogs

A

Marbofloxacin - higher AUC and Cmax

145
Q

What are teh side effects of FQs

A

Mild! Gi, nephro if dehydrated

146
Q

What are the contraindications of FQs

A

Pregnany, young (damage to growth plates), retinopathy in cats, off label in food animal

147
Q

What are the main interactions of FQs

A

Antacids, food, sucralfate, NSAIDs (Seizure)