Antimicrobials - UGHHHHH

Question 1

what do Beta Lactams do?

Answer 1

destroy cell wall via interfering with transpeptidase enzymes (responsible for cross-links between peptidoglycan strange)

Question 2

what are some restrictions of beta-lactams (the MUST haves?)

Answer 2

MUST have cell walls and/r growing (most effective during log phase of growth)

Question 3

What organisms may persist with beta lactase?

Answer 3

static

Question 4

leta-lactams have synergism with ________ thus help prevent relapse and failures in serious infections with tolerant microorganisms

Answer 4

Aminglycosides

Question 5

what is penicillin effective against?

Answer 5

many G+ (FEW G- [inactive at normal dose])

BOTH anaerobic and aerobic bacteria

Question 6

What is the exception of anaerobic and aerobic penicillin efficacy?

Answer 6

Bacteroides

Question 7

3rd generation cephalosporins are a class of _______?

Answer 7

B-lactams

Question 8

How are 3rd generation cephalosporins different than normal?

Answer 8

WIDER spectrum f activity (tx resistant G- infections in very compromised cases)

Question 9

3rd generation cephalosporins have properties like _________?

Answer 9

penicillins (BUT are more stable and temp changes)

Question 10

T/F 3rd generation cephalosporins are toxic?

Answer 10

FALSE/NOPE, relatively non-toxic (BUT repeated IV administration may cause local phlebitis)

Question 11

T/F 3rd generation cephalosporins HURT when they are injected.

Answer 11

T

Question 12

Carbapenems are a class of what?

Answer 12

New class of 3rd generation cephalosporins

Question 13

______ & ______ are among the most active drugs against a wide variety of bacteria (resistant to B-lactamase destruction) - What are they effective against?

Answer 13

imipenem and meropenem

anaerobic and aerobic microorganisms

Anaerbes are highly susceptible (Bacteroides fragilis)

Question 14

T/F toxicity is common with B-lactams?

What are some effects?

Answer 14

F (toxicity is rare)

Hypersensitivity reactions = skin reactions, angioedema, drug fever, serum sickness, vasculitis, eosinophilic, anaphylaxis

Question 15

What should be administered IV with caution esp. if hyperkalemia is present?

Answer 15

Potassium Penicillin

Question 16

What are 3 common examples of aminoglycosides?

Answer 16

Gentamycin, toramycin, amikacin

Question 17

what do aminglycosides interfere with? Are they most effective against G+ or G-

Answer 17

membrane associated bacterial ribosomes

susceptible aerobic bacteria
Mostly G- (bacilli) - ex. pseudomonas

Question 18

What facilitates the movement of Aminoglycosides across cell wall?

What decreases the movement?

Answer 18

passive movement facilitated by ALKALINE ph!

low PH increases resistance more >100x

decreased passage also with low O2 tension (hypoxic tissues) - caution with treating anaerobes in low O2 environments (NOT effective against obligate anaerobes & fungi)

Question 19

What is hella important to remember with regards to administering Beta-lactams and any drugs given after?

Answer 19

Cell wall injury from B-lactams will increase uptake of aminoglycosides

Question 20

Are aminoglycosides effective against streptococci?

Answer 20

NOT really (moderately sensitive - quite resistant)

Question 21

What is a major negative effect of animoglycosides?

what are 2 others?

Answer 21

filtered and absorbed into brush border of proximal tubule & LOH via ionization = transported into cells= sequestered in lysosomes = lysosomes rupture = accessive accumulation (mainly in renal cortex) = tubular necrosis = MONITOR renal function (evidence in 3-5d)

ototoxicity, NM blockage

Question 22

what is an example of fluoroquinolone?

Answer 22

enrofloxacin

Question 23

What does fluoroquinolone do?

Answer 23

inhibits DNA/RNA enzyme synthesis

Question 24

what is fluoroquinolone effective against?

Answer 24

aerobic G- (genitourinary, GI tract, bone inf, soft tissues/skin infections) & G+

Question 25

What are fluoroquinolone not effective against?

Answer 25

anaerobic

Question 26

what are examples of macrlids?

Answer 26

Erythromycin, azithromycin, clarithromycin

Question 27

What do macrolids do? What is is confined to?

Answer 27

interfere with protein synthesis (reversibly bind to 50s subunit of ribosome) - confined to rapidly dividing bacteria and mycoplasmas

Question 28

What are macrolids affective against?

Answer 28

G+ > G-

Question 29

Are macrolids bacteriostatic r bacteriocydal?

Answer 29

static

Question 30

T/F macrolides are concentration dependent?

Answer 30

F (they are time dependent)

Question 31

What are macrolids syngergicstic with?

Answer 31

rifampin (Rhodococcus equi)

Question 32

macrolids can be used to tx _______ infections.

Answer 32

respiratory

Question 33

_____ are sensitive to macrolid-indiced GI disturbances.

Answer 33

Horses (can be fatal)

Question 34

what do sulfonamides do?

Answer 34

blocks several enzymes needed for biogenesis and other metabolic reactions necessary for formation of RNa

Question 35

______ is great against external auditory canal infections.

Answer 35

fluoroquinolone

Question 36

are sulfonamides static or cidal?

Answer 36

static

Question 37

high concentrations of sulfonamides are found in the _____.

Answer 37

urine

Question 38

what are some potentiated sulfonamides? What do they do?

Answer 38

trimethoprim, pyrimethamine inhibit dihydrofolate reductase in bacteria and protozoa (not effective if used alone)

Question 39

what is critical in defense mechanism for bacteriostatic Abs?

Answer 39

adequate cellular and humoral defense mechanisms

Question 40

When are sulfonamides most effective?

Answer 40

early stages of acute infections (when organisms are rapidly multiplying)

Question 41

What do sulfonamides effective against?

Answer 41

G+, G-, some protozoa

Question 42

what is combined to tx protozoal disease

Answer 42

sulfonamides + pyrimethamine

Question 43

what is used to tx burns to prevent gram + & G- organisms?

Answer 43

SSD

Question 44

Concentrations of sulfonamides in _______ exceed concentrations in _________..

Answer 44

kidneys, plasma skin, liver, lungs, are slightly less than corresponding plasma concentrations

Question 45

how are sulfonamides excreted?

Answer 45

urine primarily; also in feces, milk (1-3.5x higher than plasma)

Question 46

what do tetracyclines do?

Answer 46

reversible binding of 30s subunit (prevention ribosomal translation)

Question 47

How are tetracyclines further classified (include examples)

Answer 47

short acting - oxytetracycline, intermediate acting - de-methyl-choro-tetracycline long acting = doxy

Question 48

Are tetracyclines static or cidal? Are they concentration or time dependent?

Answer 48

static time

Question 49

Where are tetracyclines found in high concentrations in the body?

Answer 49

kidneys, liver, bile, spleen, lungs, bone

Question 50

tetracyclines are the drug of choice to tx ____ & ____.

Answer 50

rickettsia & mycoplasma

Question 51

what are tetracyclines effective against?

Answer 51

G +, G-, anaerobe, aerob., even some protozoa

Question 52

What is a SE of tetracyclines?

Answer 52

D in horses (esp, of animal is critically ill or stressed) chelate Ca in teeth & bones (yellow-brownish discoloration, impairs healing) rapid Iv injection = hypotension nephrotocic WBC chemotactic/phagocytosisi

Question 53

What is an examples of a phenol?

Answer 53

chloremphenicol

Question 54

What are phenols effective against?

Answer 54

G+, G-, anaerobes (bactericides fragilis)

Question 55

phenols are known to be...

Answer 55

highly effective well tolerated broad spec Abs

Question 56

what do phenols do?

Answer 56

inhibit microbial protein synthesis by binding to 50s bubonic of 70s ribosome (IMPAIRS peptide transferred activity)

Question 57

are phenols static or cidal?

Answer 57

static (can be Cidal in high concentrations)

Question 58

Where are phenols absorbed?

Answer 58

upper GI

Question 59

T/F chloramphenicol doesn't undergo hepatic metabolism?

Answer 59

FALSE - it undergoes extensive haptic metabolism (liver dz prevents normal metabolic degradation and active Ab accumulates in body)

Question 60

What is an example of glycopeptide?

Answer 60

vancomycin

Question 61

what do glycopeptides do?

Answer 61

prevents cell wall synthesis and produces rapid bactericidal effect in DIVIDING bacteria

Question 62

What are glycopeptides effective against?

Answer 62

G+ (NOT against G-)

Question 63

where are glycopeptide excreted?

Answer 63

kidneys (in ACTIVE form)

Question 64

what are some hypersensitivity reactions related to glycopeptides?

Answer 64

ototoxicity | nephrotoxicity

Question 65

what are Nitroimidazles used to tx?

Answer 65

protozoa ABs | anaerobic

Question 66

what is an examples of Nitroimidazle?

Answer 66

metronidazole

Question 67

T/F Nitroimidazles can be used off label in feed animals?

Answer 67

FUCK NO! | this is prohibited

Question 68

metronidazole is effective against what?

Answer 68

ptotozoa + obligate anaerobic bacteria (Bacteriodes fragilis, B. melanogenicus, Fusobacterium, C. perfringens, other clostridial inf)

Question 69

metronidazole is NOT effective against what?

Answer 69

facultative anaerobes, obligate aerobes, microaerophilic bacteria

Question 70

how is metronidazole absorbed?

Answer 70

in GI (bioavailability = 60=100%) - serum concentrations in 1-2h (widely distributed to all tissues) - penetrates BBB - attains tx concentrations in abscesses & empyema fluid

Question 71

What is a weird thing that metronidazole is also effective against?

Answer 71

adjunct to tx solid tumors (radiosensitizors)

Question 72

How do NSAIDS work?

Answer 72

reduce biosynthesis of Prostaglandins via inhibiting COX (converts arachidonic acid into prostaglandins) = impairs inflammatory process

Question 73

where is Cox 1 found? | what is it classified as?

Answer 73

all tissues | constitutive

Question 74

Where is cox 2 found? | what is it classified as?

Answer 74

damaged or inflamed tissues | non-constitutive (also involved in thermoregulation and pain response)

Question 75

What are the bodies NORMAL protective mechanisms?

Answer 75

``` D ulcers colic protein less right dorsal colitis renal papillary necrosis toxicity ```

Question 76

What do most NSAIDS on the market tx?

Answer 76

cox 1 & cox 2

Question 77

what is the cox 2 inhibitor on the market?

Answer 77

firocoxib

Question 78

what is flunixin meglamine commonly used to tx?

Answer 78

pain & enodtoxemia associated with colic (helps with arterial hypoxemia, vasdilation, CV shock, D)

Question 79

what can be used with lameness exams?

Answer 79

lidocaine (30-45 mins), bupivicane (90-120mins), mepivicaine HCL (4-6hrs)

Question 80

complications of nerve blocks

Answer 80

broken needle shaft SC infection synovial infection