wk 6- antibacterials Flashcards
principles of antibacterial action
-target cells that are living and reproducing within the human body
-target strcutures that are unique to bacterial cells and NOT human cells (selective toxicity)
-move to site of infection
-destroy pathogenic microorgnisms
-eliminated from body without affecting structure or function of human cells
bacterial antibiotic targets
- cell wall synthesis inhibitors
-human cells dont have a cell wall - protein synthesis inhibitors
bacteria have different ribosome subunits than human cells - inhibitors of DNA synthesis
bacteria have circular DNA not in a nucleus - inhibition of folic acid synthesis
bacteria need folic acid to produce proteins for growth
antibacterials that podiatrist can prescribe- to make recommendations understand what you can use
cephalosporin
lincosamides
macrolides
nitroimidazoles
penicillins
quinolones
tetracylines
goal of AMT
kill or inhibit growth of pathogens using selective toxicity to allow host defence system to remove it
difference between structure of bacterial cells and human cells
human cell:
-cell membrane
-ribosomes have 80S type with 60S and 40S subunits
-linear DNA
-membrane bound organelles
bacterial cell:
-no nucleus/nuclear membrane
-ribosomes have 70S type with 50S/30S subunits
-circular DNA
-no membrane bound organelles
-cell wall
cell wall synthesis inhibitors drug classes
- beta-lactams: penicillin, cephalosporin, carbapenems and monobactems
- glycopeptides: vacomycin
mechanism of action of penicillin and examples
bactericidal time dependent killing
-interfere with cell wall sythesis by binding to PBPs
amoxicillin w/wo clav acid
penicillin G, V (IV only)- narrow spectrum
flucoloxacillin- narrow spectrum penicillinase resistan
t
phenoxymethylpenicillin
adverse effects, precautions and contraindications of common classes of antibacterials
what does taking clavulanic acid with penicillins do
protect the antibacterials from inactivation by microbes that produce b lactamases
clav acid is a b lactamase inhibitor
renal impairment - amoxicillin
high IV injection doses or prolonged treatment may result in eletrolyte disturbances due to sodium content
resullting in neurotoxicity, neutropenia
for renal impairment what can you do for dose of amoxicillin
decrease dose or increase interval
reduce dose if clearance is less than 10mL/minute- amoxicillin
is amoxicillin safe in pregnancy and breast feeding?
preg- safe
BF- safe, dose just after breastfeeding and watch for changes in GIT
adverse effects of common antibiotics
adverse effects of penicilin
nausea
diarrhoea
rash
superinfection with prolonged treatment of broad spectrum penicillins
rare:
-neurotoxicity
-neutopenia
-cholestatic hepatitis
MOA for cephalosporin
bactericidal
time dependent killing
examples
cefalexin
carbepenems