ABx Flashcards
G+ cocci to know
staph, strep, entero
G+ bacilli
bacilus anthracis, clostridium diptheria
G- cocci
neiseria gonnorhoeoa, meningitides
gram- bacilli
e coli, proteus, enterobacter, salmonema
sprichetes
treponema pallidum
acid fast bacteria
mycobacterium tuberculosis, bovis, leprae
antibiotic strategies
employ a substances that attacks a non-mammalian part of the growth process
slow growth so the immune system gains the upper hand
employ agents to kill log order growth in immune compromised patients
what is the risk of introducing substances that act against non-mammalian metabolism
there will be an allergic event
three factors to fight ABx resistance
long enough treatment
only use Abx when necessary
use a combination of Abx when needed
how can the same drug be bacteriocidal and bacteriostatic
at a low dose it might just kill enough microbes to keep the net colony growth to zero
a higher dose might kill all the colonies faster than they can be replaced
what is the goal of a bacteriocidal drug
to allow the immune system to catch up
how do you decide to use bacteriostatic vs cidal
healthy patients can use either, but immunocompromised patients bacteriocidal agents should be used
cell wall active drugs are generally _____
protein synthesis inhibitors are usually _____
bacteriocidal
bacteriostatic
four targets of ABx action
cell wall synthesis
protein synthesis
nucleic acid synthesis
inhibitor of folate biosynthesis (inhibitors of metabolism)
why is inhibition of folate a good method to kill bacteria
folate is needed to make DNA
humans are able to take in folate but bacteria need to convert it from other substances
if we can block conversion the bacteria will die and spare our cells
two groups of cell wall inhibitors
beta lactams
others
four beta lactam ABx
´Penicillins
´Cephalosporins
´Carbapenems
´Monobactams
non beta lactam ABx that target cell walls
´Vancomycin
´Daptomycin
´Bacitracin
four penicillin types
natural
anti staphyolococcal
extended spectrum
anti pseudomona;
natural penicillin is used against what
Gram + except staph
syphilis
antistaph penicillin
what are they used against
methicilin
cloxacin
nafcillin
oxacillin
staph infections except MRSA
what is the goal of extended spectrum penicillins
improve gram negative coverage
two common extended spectrum penicillins
common probelms
ampicilin (oral and parenteral)
amoxicilin (oral only)
rash
aminopenicillins (ampicillin, amoxicilin) are used on what
Otitis media
strep
UTI (where ther isk of resistant e coli is low
anti pseudomonal penicllin
´Carbenicillin (Geocillin)
´Mezocillin (Mezlin)
´Piperacillin (Pipracil)
´Ticarcillin (Ticar)
what is the most powerful antipseudomonal penicillin
piperacillin
used in intrabdominal infections but is susceptible to beta lactamase
toxicicty to penicilin
hypersensitivity (rash, angioedema, anaphylaxsis)
diarrhea
nephritis (exp mthicillin)
synergistic drugs with penicillins
aminoglycosides, but can be mixed in the same vial
antagonistic drugs with penicillin
bacteriostatic agents will decrease the effective ness of bacteriocidals, so macrolides and tetracyclines dont work with penicillin
how can penicillins be used to fight beta lactam producing bacteria
add a beta lactamase inhibitor (clavulanic acid)
amoxicillin with clavulanic acid = _____
ticarcillin + clavulanic acid = ____
augmentin
timentin
two important 1st gen cephalosporins
cefazolin, cephalexin
3rd genetation cephalosporin to remember
rocephin
what are cephalosporins used for
treating mainly gram + with some gram - coverage depending on generation
4th genetation cephalosporin to know
cefepime (esp against pseudomonas)
5th geneation cephalosporin to know
ceftaroline
only beta lactam useful against MRSA
adverse effects associated with cephalosporin
allergic cross reactive with penicillin (3-5%)
1-2% allergic reaction with no pen allergy
can also cause bleeding due to anti vitamine K action
advantage of monobactum
what is it used for
relatively beta lactamase resistant, low allergic reaction potential with penicillin allergy
usually against enterobacter and other G-. not G +
monobactum to know
azetronam
T/F carbapenems are not cross reactive with penicillin/ceph allergies
false, they can be
advantages of carbapenems
adverse effects
broad spectrum
expensive, nausea, diarrhea, can cause sz
nonbeta lactams
´Vancomycin (Vancocin)
´Bacitracin (ointment, Neosporin, Polysporin)
´Fosfomycin (Monurol): UTI treatment
´Cycloserine (Seromycin)
why is vancomysin important
because it works for most bacteria and is controlled to prevent resistance
vancomycin toxicity
´Nephrotoxicity
´Ototoxicity
´Flushing due to histamine release
´“Red Man Syndrome”
red man syndrome
flushing diue to histamine release realted to vancomycin
when is vancomycin used
MRSA
enterococcus
clostridium (oral)
uses for daptomycin
disadvantages
G+ coverave for resistant staph, strep, enterococcus
parenteral only, not useful in pneumonia, must stop statins
what is telavancin used for
similar to daptomycin
reserved for mrsa
can prolong QT interval
interferes with some blood tests
types of protein inhibiting ABx to know
tetracyclines
aminoglycosides
macrolides
tetracyclines are most often used in what setting
outpatient
are tetracylcines bacteriostatic or cida
static, but not against gram negative UTIs
tetracycline is especially useful against what
chlamydia
mycoplasma
rickettsia
cholera
anthrax
acne
three tetracylcines to know
tetracycline
doxycycline
minocyclin
what inhibits absorption of tetracylcline
dairy
T/F tetracycline has anti-inflammatory effect
true, which makes it useful in acne treatment
T/F doxycycline is not affected by renal disease
true it is almost entirely metabolized in the liver
special contraindications for tetracycline
pregnancy and children under 9 due to dental enamal dysplasia and discoloration, growth inhibition, bone deformities
photosensitive, so wear sin screen
most common tetracycline complaint
gastric distress, but that can be combated by taking it with food
tetracycline derivative that can be used against resistant staph and strep in IV formuation
adverse effects?
tigecycline
similar to tetracycline with more nausea and vomitting
are aminocylcosides bacteriostatic or cidal
cidal
T/F aminoglycosides are usualyl used alone and are effect against G+ infections
false, they are almost always used with a specific G+ agent (cilin or cephalosporin) and work well against G-
T/F aminoglycosides are absorbed well in oral form
false, they are for parenteral use only
three notable aminoglycosides
amikacin, gentamicin, tobramycin
aminoglycocide toxicity (2+1)
ototoxic
nephrotoxic
exacerbated by loop diurectics (furosimide/lasix or bumetanide/bumex)
what type of bacteria are macrolides useful against
good against G+, useful against “Others” like chlamydia
weak against G-
T/F erythromycin are safe for kids and pregnancy
true
what is the treatment for syphilis in the penicillin allergic patient
erythromycin
macrolides to know
erythromycin
azithromycin
clarithromycin
thelthromycin
what is the advantage of ketolides over macrolides
one example of a ketolide
broader spectrum of action with less antibacterial resistance
telithromycin
typical dosage of azithromycin
500mg on day one, 250mg on days 2-5
macrolide toxicity
GI distress
drug interactions fomr CYP3A4 inhibitors
why do macrolides cause GI distress
macrolides mimic the structure of a natural chemical called motilin that triggers peristalsis
macrolides are CYP3A4 inhibitors
why is that relevant
it stops many drugs from being broken down and can cause the circulating blood levels of some othe rmedications to increase to dangerous leveslk
drugs that can have a dangerous interaction with erythromycin due to CYP inhibition
astemizole
carbamazepine
warfarin
