Antibiotics Flashcards
bactericidal
kills bacteria
bacteriostatic
inhibits bacterial growth
narrow spectrum antibiotic
broad spectrum antibiotic
penicillin
tetracycline
vancomycin is a glycopeptide, how does it work
attacks cell wall
3 examples of antibiotics which work on the cell wall
penicillin
cephalosporins (ceftriaxone)
glycopeptides (tetracycline)
t/f gram -ve organisms have a thick layer of peptidoglycan and a single phospholipid bilayer
false
gram +ve do
which type of organism has two phospholipid bilayers and a thin layer of peptidoglycan
gram negatives
how does penicillin work
inhibits cell wall synthesis by preventing cross-linking of peptidoglycan subunits
t/f penicllin is bacteriostatic
false
bacteriocidal
3 examples of penicillins
flucloxacillin
co-amoxiclav
amoxicillin
when would flucloxacillin be used
skin and soft tissue infection
wound infection
cellulitis
penicillin is a beta-lactam antibiotic, what is this
broad spectrum antibiotics which contain a beta-lactam ring
cephalosporins also example
which antibiotic bind to end of growing chain, prevents cross-linking and weakens bacterial cell wall
glycopeptides
t/f glycopeptides are only active against organisms with gram +ve cell walls
true
why is there a limited use of cephalosporins in hospital
may induce clostridum difficile infection
ceftriaxone is what type of antibiotic
cephalosporins
cephalosporins work by
inhibiting cell wall synthesis
example of a glycopeptide
vancomycin
how do glycopeptides work
binds to end of growing chain, prevents cross-linking and weakens bacterial cell wall
t/f vancomycin can damage liver
false -excreted in urine
may damage kidneys
macroslidfes, tetracyclines and aminoglycosides are antibiotics which
inhibit protein synthesis
doxycycline is an example of
a tetracycline
erythromycin, clarithromycin and gentamicin are examples of
trick question
erythromycin and clarith belong to macroslides, gentamicin beelongs to aminoglycosides
if the drug ends in mycin, what is like likely to be
a macroslide
out of the antibiotics which inhibit protein synthesis, which ones are bacteriostatic/cidal
bacteriostatic - macroslides and tetracyline
cidal - aminoglycosides
where do antibiotics which inhibit protein synthesis attach to the organism?
at the bacterial ribosomes
disadvantages of using doxycycline
can destruct intestinal flora, leading to 2ndary infections
can permanently stain teeth of children <12yrs
which antibiotic is useful if it seems the infection can ‘hide’ from immune system? what aspect allows it to be effective
macroslides
lipophilic and pass through cell membranes easily
which antibiotic is bactericidal yet mainly active against gram -ve aerobic organisms
aminoglycosides
disadvantages of aminoglycosides (gentamicin)
kidney damage
damage of CN VIII (vestibulocochlear)
what would suggest there has been damage to a cranial nerve from using an antibiotic
acute symptoms of deafness and dizziness
t/f aminoglycosides exctreted via biliary tract
false
excreted via kidneys
t/f doxycycline excreted via kidneys
false
cycline = tetracycline, these are excreted using the biliary tract
3 examples of drugs which act on Bacterial DNA
metronidazole
floroquinolones
timethoprim
which antibiotic causes strand breakage in DNA
metronidazole
t/f timethoprim interacts with alcohol
false
metronidazole interacts with alcohol
which antibiotic is used to treat true anaerobic infections
metonidazole
t/f trimethoprim is active against both gram+/- organisms
true
trimethoprim works by
inhibiting folic acid synthesis
why would inhibiting folic acid synthesis be an effective target for antibiotics
folic acids are required for amino acids
ciplrofloxacin and levofloxacin are examples of
floroquinolones
how do fluroquinolones work
inhibits supercoiling of DNA
adverse effects of fluroquinolones 3
c.diff
weakens tendons
causes seizures
how is fluoroquinolone excreted
urine
t/f nausa, vomiting and diarrhoea are side effects of all antibiotics which target protein synthesis
false
side effect of all due to disrupting gut flora
which antibiotic may cause tendonitis
ciprofloxacin
bacterial resistance can occur due to
suboptimal dosage
5 drugs that should be avoided if pregnant
trimethoprim metranidazole gentamicin tetracycline fluoroquinolones
3 ways antibiotic resistance can occur
- change in bacterial DNA leads to a change in the gene, and so antibiotic has wrong target
- bacteria codes enzymes which deactivate/degrade drug
- efflux pumps drug out of cell, genetic change may cause increase in efflux
