antibiotics Flashcards
what do bactericidal do ?
kill bacteria
what do bacteriostatic do ?
inhibit bacterial growth
what antibiotics don’t work on the cell wall ?
penicillin
Cephalosporins - ceftriaxone
glycopeptides - vancomycin
how do penicillins inhibit cell wall synthesis ?
by preventing cross-linking of peptidoglycan subunits
what is penicillin classed as ?
batericidal
what is flucloxacillin ?
gram positive organism
very narrow spectrum antibiotic
what is flucloxacillin commonly used for ?
skin and soft tissue infection
wound infection
cellulitis
what antibiotics are bactericidal ?
cephalosporins
glycopeptides
describe cephalosporins
bactericidal
inhibit cell wall synthesis
may induce clostridium difficile so their use is limited in hospital
What is glycopeptides ?
cell wall active antibiotics
how does glycopeptides work ?
binds to end of growing chain
prevents cross-linking
weakens bacterial cell wall
when does glycipeptides work ?
only active against organisms with gram positive cell walls
what antibiotics inhibit protein synthesis ?
macrolides
tetracyclines
aminoglycosides
what are examples of macrolides ?
erythromycin
clarithromycin
azithromycin
What are examples of tetacyclines ?
doxyxycline
give an example of an aminoglycosides ?
gentamicin
are drugs that inhibit protein synthesis bacteriostatic ?
yes, only macrolides and tetracyclines
what do macrolides, tetracyclines and aminoglycosides have in common ?
antibiotics that inhibit protein synthesis
attach to bacterial ribesomes
what are charecteristics of macrolides ?
lipophilic
pass through cell membranes easily
what organisms are aminoglycosides mainly active against ?
give two examples
gram negative aerobic organisms
e.g. coliforms and pseudomonas
what can aminoglycosides be classed as ?
bactericidal
what is a downside of aminoglycosides ?
very toxic
kidney damage
damage of CN VIII (vestibulocochlear)
what can damage of CN VIII cause ?
deafness and dizziness
what antibiotics act on bacterial DNA ?
Metronidazole
Trimethoprim
Fluroquinolones
how do metronidazole work ?
causes strand breakage of bacterial DNA
what do metronidazole treat ?
treat true anaerobic infections
how does trimethoprim work ?
inhibits bacterial folic acid synthesis
what do trimethoprim fight against ?
gram negative and gram positive
What are example of fluoroquinolones ?
ciprofloxacin
levofloxacin
what do fluoroquinolones prevent ?
supercoiling of bacterial DNA
what class are fluroquinolones ?
bactericidal
what is a disadvantage of fluoroquinolones ?
restricted use in order to prevent clostridium difficile
describe gram positive and gram negative organisms ?
gram positive organisms - cell wall has thick layer of peptidoglycan and a single phospholipid bilayer
gram negative - cell wall has two phospholipid bilayers and a thin layer of peptidoglycan
