Rational antimicrobial therapy Flashcards Preview

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Flashcards in Rational antimicrobial therapy Deck (46)
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1
Q

Grampositiveaerobicbacteria

A

Strep

Staphaureus

2
Q

Gramnegativeaerobicbacteria

A

E coli

Helicobacter

3
Q

Anaerobicbacteria

A

Clostridiumperfringens

4
Q

Atypical bacterial species

A
Rickettsia
Mycoplasma
Chlamydia
Borrelia
Bartonella
Mycobacterium
5
Q

Bacterialresistance

A

some bacteria have resistant genes

use of antimicrobials creates a selective pressure

6
Q

Whentouseantimicrobials?

A

definitivelydiagnosed/likelydiagnosis
diseaselikelytoprogresswithoutmedicaltherapy
Wouldcausecriticalillnessifitwasnotrecognisedortreated

7
Q

factors to consider when choosing antimicrobial

A

likelybacteriainvolved
likelysusceptibility
cultureneeded/feasible?
pharmacokineticfactorsyouneedtoconsider?
potentialsideeffects+incrriskinyourpatient?
clientcomplianceissues?
costconsiderations?

8
Q

Factors affecting the success of antibacterial therapy

A
Whatbugslivewhere?
Bacterialsusceptibility
Distributiontothesiteofinfection(pharmacokineticphase)
Localconditions(pharmacodynamic phase)
Clientcompliance
9
Q

Bacterialsusceptibility

A

if not susceptible in vitro - resistant in vivo
if susceptible in vitro - may work in vivo
resistancemaybeovercomebyhighconcsachievedinurineortopicalapplication

10
Q

MIC

A

MIC=Minimuminhibitoryconcentration
Lowestconcofdrugthatwillinhibitbacterialgrowth
MIC90 usualmeasureusedtodeterminetherapeuticdose - Concthatwillinhibit90%ofisolates

11
Q

Inhibitionofcellwallsynthesis

A

penicillins
cephalosporins
bacitracin

12
Q

Inhibition of cell membrane function

A

polymyxins
amphotericinB
imidazoles
nystatin

13
Q

Inhibition of protein synthesis

A
chloramphenicol
macrolides
lincosamides
tetracyclines
aminoglycosides
14
Q

Inhibition of nucleic acid synthesis

A
sulphonamides
trimethoprim
quinolones
metronidazole
rifampin
15
Q

Bacteriostatic - define

A

Tempinhibitthegrowthoforganisms
Effectisreversibleoncethedrugisremoved
drugconc atthesiteoftheinfectionshouldstayabovetheMICthroughoutdosinginterval
Manybacteriostaticdrugscanbebactericidalifdrugexposureissufficientlyhighorprolonged

16
Q

Bacteriostatic drugs

A
Chloramphenicol
Lincosamides
Macrolides
Tetracyclines
Non-potentiatedsulphonamides
(mostly inhibit protein synthesis)
17
Q

Bactericidal - define

A

Underidealconditionskillbacteria
preferredwhenconcernabout siteofinfectionorhostdefence
gram+veinfections - susceptibility ofbacteriaandabilityto
penetratetissuemoreimportantconsiderations

18
Q

Bactericidal drugs

A
Penicillins
Cephalosporins
Aminoglycosides
Fluoroquinolones
Potentiatedsulphonamides(TMPS)
Metronidazole
19
Q

why not to give Penicillins, Cephalosporins + TMPS with bacteriostatic drugs

A

Bacterianeedtobemultiplyingfordrugstobeeffective

20
Q

concentration dependant drugs

A
Aminoglycosides
Fluoroquinolones
Metronidazole
Peakconcentrationachievedorareaunderthecurvepredictstherapeuticsuccess
can be given with bacteriostatic drugs
21
Q

drugs v. bad against gram +ve aerobes

A

Aminoglycosides

Metronidazole

22
Q

drugs v. bad against gram -ve aerobes

A

Metronidazole
Penicillin G
Lincosamides/Macrolides

23
Q

drugs v.bad against obligate aerobes

A

Fluoroquinolones

Aminoglycosides

24
Q

drugs v.bad against penicillinase producing staph

A

Penicillin G
Aminopenicillins
Metronidazole

25
Q

drugs v. good against gram +ve aerobes

A
Penicillin G
Aminopenicillins
Lincosamides/
Macrolides
Tetracyclines
26
Q

drugs v. good against gram -ve aerobes

A

Fluoroquinolones
Aminoglycosides
Ticarcillin-clavulanate
Cephalosporins

27
Q

drugs v.good against obligate aerobes

A
Penicillin G
Amoxy-clav
Clindamycin
Metronidazole
Chloramphenicol
Rifampin
28
Q

drugs v.good against penicillinase producing staph

A
Amoxy-clav
Cephalosporins
Cloxacillin
Fluoroquinolones
Rifampin
29
Q

drug most good but leaves some important gram +ve aerobes

A

Fluoroquinolones

30
Q

drug most good but leaves some important penicillinase producing staph

A

Clindamycin

31
Q

drug most good but leaves some important gram -ve aerobes

A

Amoxy-clav

32
Q

cephalosporins,cefovicinandamoxycillin

A

50/50 susceptible/resistant - obligate anaerobes + -ve aerobes

33
Q

TMPS

A

50/50 susceptible/resistant all quadrants

34
Q

Tetracyclines

A

50/50 susceptible/resistantallquadrantsexceptgrampositive
aerobes

35
Q

Difficult to access areas

A
Brain
Eye
Prostate
Bronchus
Mammarygland
Intracellular
Poorlyvascularisedtissues - Bonefragments, Heartvalves
36
Q

Intracellular bacteria

A
Bartonella
Brucella
Chlamydophila
Mycobacterium
Rickettsia
Staphylococcus
37
Q

poor penetration

A
Penicillins
Cephalosporins
Betalactamase
inhibitors
Polymixins
Aminoglycosides
38
Q

good penetration

A
Sulphonamides
Trimethoprim
Lincosamides
Macrolides
Tetracycline
39
Q

great penetration

A
Chloramphenicol
Fluoroquinolones
Lipophilic
tetracyclines
minocycline
doxycycline
Metronidazole
Rifampin
40
Q

Environmentalconditions - Foreignmaterial

A

phagocytesdegranulatetotrytodestroytheforeignmaterial
inefficientinkillingbacterialpathogens
canprotectbacteriafromantibacterialdrugsandphagocytosis - bacteria can form a biofilm

41
Q

Penicillinactivityreducedinpresenceof

A

haemoglobin

42
Q

Post operative infection risk factors

A

Clinicalstatusofpatient - Incrriskforshocked/emaciatedpatients
Natureofsurgery - Incrriskforemergencyprocedures
Useofimplants
Experienceofsurgeon
duration of operation
Administeringpropofol - 3.8x more at risk
Clipping - before induction 3x more likely
poor BCS
concurrentendocrinopathies

43
Q

when to use prophylactic antimicrobials

A

non-clean surgery
dentalprocedures?
patientswithleukopenia(viral,druginduced)
orthopaedicandmajorabdominalandthoracicsurgery
surgicaltime>90mins
consequencesofinfectionwouldbedisastrous

44
Q

Antibiotics can not compensate for

A

grosscontamination
Localtissuetrauma
Compromisedpatienthealth

45
Q

Surgicalprophylaxis ‐ timing

A

Administerbeforeprocedure
drugmustbepresentinthewoundatthetimeofbacterialcontamination
LAformulationofamoxycillintakes12hourstoreachtherapeuticconcs

46
Q

situations when antimicrobials are inappropriate

A

Dogspresentingforvomiting d/tacutegastritis
YoungcatswithsignsofLUTdisease
Bloodinfaeces
Routinesurgery