other antibiotics Flashcards
what is the mechanism of resistance of chloramphenicol ?
plasmid encoded acetyltransferase inactivates the drug
who are the quinolones ?
anything that ends with floxacin
what is the mechanism of quinolones ?
inhibit bacteria for DNA synthesis
DNA gyrase ( topoisomerase II)
topoisomerase 4
what are the mechanism of resistance of quinolone ?
altering of cell permeability
mutations in DNA gyrase and topoisomerase 4
plasmid mediated resistance
what are the clinical uses of quinolones ?
gram negative rods of the urinary tract and GI tracts
UTI
pseudomonas
abdominal infections
UTI in adults vs children ?
adults - fluoroquinolone
children - bactrim
what drug has the most reliable pseudomonas coverage ?
ciprofloxacin
what are the side effects of quinolones ?
GI upset
mild neurologic side effects
cardiac arrest
tendon rupture , more common in older patients
toxic to developing cartilage
what is the cause of cardiac arrest in quinolones ?
prolonged QT interval which can lead to torsades des pointes
what drug may affect the absorption of quinolones ?
antacids
aluminium
what is the mechanism of vancomycin ?
inhibits peptidoglycan formation
binds d-alanyl-dalanine peptides
prevents cross linking
what is the difference in the mechanism of action between vancomycin and beta lactams ?
beta lactams inhibit transpeptidases
vancomycin block transpeptidases binding
what are the mechanisms of resistance to vancomycin ?
terminal amino acid change
which is the mechanism in which VRSA emerges
what type of bacteria is vancomycin effective against ?
only gram positive bacteria
what are the clinical scenarios in which vancomycin is used ?
MRSA
oral vanco for c difficile infection
what are the adverse effects of vancomycin ?
1- neprotoxicity , increased risk especially if given with aminoglycosides
2- ototoxicity
3- Red man syndrome
4- DRESS syndrome
what is the cause of red man syndrome ?
direct activation of mast cells , allows for histamine release
infusion related side effect
what type of bacteria is metronidazole effective against and why ?
only active in anaerobic bacteria
because the drug must be reduced for it to work and this can only happen in anaerobic bacteria
what are the uses of metronidazole ?
1- anareobic bacteria below the diaphragm
2- used for infections caused by h pylori
3- infections caused by gardnerella vaginalis
bacterial vaginitis and triple therapy in h pylori
what drug is commonly co administered with metronidazole ?
gien with quinolones
what drug combo is usually used for diverticulitis ?
cipro flagly
which protozoa are sensititive to metronidazole ?
trichomonas vaginalis
entamoeba histolytica
giardia lamblia
what are the known side effects to metronidazole ?
metallic taste
abdominal discomfort and nausea
disulfram reaction
what drugs are associated with disulfram reactions ?
metronidazole
cephalosporins
sulphonamides
what is the only use of nitrofurantoin ?
UTI
2 main facts that must be known about furantoin ?
used for UTIs in pregnancy
can trigger hemolysis in G6PD patients
