Antibiotics

Question 1

what is the PkPD?

Answer 1

pharmokinetics (animal metab/exc) and -dynamics (drug effects on target)

Question 2

how do you test for antibiotic susceptibility?

Answer 2

agar with bacteria and ‘wells’ of Abx at diff conc OR diff abx. see what one kills off bacteria

Question 3

Name a narrow spectrum Abtx and a broad spectrum (basics)

Answer 3

narrow = penG
broad = FQs

Question 4

name some potential drug targets on both gram+ and - bacteria

Answer 4

b-lactamase
peptidoglycan
b membrane
- have outer envelop!

Question 5

what is empiric therapy?

Answer 5

Tx wo ID of the bacteria, use broad spectrum Abx

Question 6

what is definitive therapy?

Answer 6

organisms ID’d and specific narrow spec Abx chosen

Question 7

what is prophylactic mean?

Answer 7

preventative. to prevent initial or reoccuring infection

Question 8

what is metaphylaxis (in vet terms)

Answer 8

therapy to control an outbreak. Not all treated animals will be infected

Question 9

What is MIC

Answer 9

minimal inhibitory concentration (of drug that prevents the bacterial growth)

Question 10

what is a breakpoint?

Answer 10

bases MIC for wild strains and other published data. compared to see if it will work in that isolate

Question 11

what is a biofilm?

Answer 11

impermeable barrier to immune/drugs
slow growth
hypermutability - often resistant phenotypes

Question 12

name 2 sp which create a biofilm

Answer 12

s. pseudintermedius

Pseudomonas spp

Question 13

name some places which following absorption the drug goes…..

Answer 13

liver - portal
bile - enterohep circulation
RBCs
receptor
kidney - excr/reabs
sweat/saliva etc

Question 14

what are the adv of inj Abx

Answer 14

total dose in systemic circ
immediate onset
inc compliance (vet des it!)

Question 15

what are some disav of inj abx?

Answer 15

painful, cost and may req aseptic tech, SE

Question 16

how must IV abx be given

Answer 16

slowly (CRI!

Question 17

what are some important qualities for a orally administrated abx?

Answer 17

stable in acid
lipid sol!
non-polar so can diffuse

Question 18

what is the bioavailbility of a drug?

Answer 18

extent and rate at which a drug is available at infection site after administration

Question 19

is both the 1st pass effect and bacteria in gut lumen always bad for orally admined drugs/

Answer 19

no - they can activate pro drugs!

Question 20

what is the kidneys effect on drugs

Answer 20

eliminates unchanged

Question 21

what is the livers effect on drugs

Answer 21

–>metabolites

inactivate or activate

Question 22

when does resistance normally develop

Answer 22

just when commensal, not usually (exc FQs) during abx

Question 23

name 3 basic mech for all Abx

Answer 23

1. cell wall inhib
2. proteins synth inhib
3. inhib DNA metab

Question 24

name 2 cell wall inhib

Answer 24

B-lactams

polymixins

Question 25

name 3 protein synth inhib

Answer 25

aminoglycosides macrolides tetracyclines

Question 26

name 3 DNA metab inhib

Answer 26

sulfonamide FQs metronidazole

Question 27

what are b-lactams

Answer 27

penecillins (narrow) | cephalosporins (broad)

Question 28

what are the basic properties of the penecillins

Answer 28

``` Kid not aX BBB weak acid time above MIC vital not orally in any smallie!! ```

Question 29

how do the protein synth inhibitors work

Answer 29

bind to bacterial ribosomes (either 50S or 30S strand). reversibly (static) or irreversibly (cidal)

Question 30

what bacteria do aminoglycosides work best against?

Answer 30

``` +'ve = staph and strep -'ve = e coli, salmonella.. ```

Question 31

what are the main properties of aminoglycosides

Answer 31

``` 50S strand wide distrubution not BBB synergistic with b-lactams! thx for breaking cell wall kidn ```

Question 32

what are the main properties of tetracyclines

Answer 32

``` 30S strans -static gram + & - & mycoplasma not BBB kidney ```

Question 33

name a tetracycline NOT exc via kidneys

Answer 33

doxycyline (faeces instead!)

Question 34

name a naturally occuring narrow spectrum macrolide

Answer 34

erythromycin | - derivative - clarithromycin are broader spectrum

Question 35

what are macrolides effective against

Answer 35

upper resp tract anaerobes | atypical bacteria

Question 36

how are the macrolide excreted

Answer 36

bile

Question 37

lincosamides also inhib protein synthesis. what are they active against

Answer 37

Gram + & - anaerobes Gram + aerobes NOT gram - aerobes

Question 38

how do DNA synth inhib, Sulfonamide work?

Answer 38

block PABA (not mammalian!) which stops synth of pyrimidine and purines

Question 39

describe the distrubution of Sulfonamides

Answer 39

wide, inc CSF

Question 40

what is the disadv of sulfonamides??

Answer 40

sever SE pos, inc dec h-poeisis

Question 41

desc basic properties of FQs

Answer 41

``` broad spec +++ tissue penetration and +++ half life gram -'ve inf +++!! NOT anaerobes atypical bact ++ ```

Question 42

are FQs cidal or static

Answer 42

conc- dependant cidal

Question 43

how are FQs elim

Answer 43

kid and liv

Question 44

what is metronidazole active against?

Answer 44

protozoa | anaerobes

Question 45

what are some properties of metronidazole??

Answer 45

``` CSF penetration inhib DNA synth pro-drug given cidal (conc-dependant) metab in liver ```

Question 46

name some cidal drugs

Answer 46

FQs B lactams Metronidazole

Question 47

name some static drugs

Answer 47

tetracyclines | macrolides

Question 48

main ways bacteria become resistant

Answer 48

``` pump ab out change porins so cant get in (aminog) inactivate ab (blact) alter target (fq) biofilm ```

Question 49

where do biofilms like to grow

Answer 49

GIT, wounds, skin infection, indwelling devices, UTIs

Question 50

what are some animal factors in need of consideration before abx?

Answer 50

``` age - liver enzyme activity? hepat/renal failure? allergy immunosuppressed already? withdrawal client compliance blood supply? ```