antibiotics Flashcards
structural components of gram negative bacteria?
LPS, lipid bilayer of cytoplasmic membrane, hydrophilic pores, nutrient receptor proteins on outer membrane
structural components of gram positive bacteria?
teichoic & teichuonic acid, lipid bilayer of cytoplasmic membrane, nutrient transport proteins of cytoplasmic membrane
what are the 3 common drug targets that utilize selective toxicity?
- disrupt genetic machinery 2. block protein synthesis 3. disrupt cell wall/membrane synthesis
an agent that will kill the bacteria
bactericidal
an agent that will inhibit the growth of the bacteria, but will not kill the bacteria
bacteristatic
do bacteristatic or bactericidal agents rely on the host immune system to get rid of microbe?
bacteristatic
lowest concentration of an antimicrobial agent that will inhibit the visible growth of bacteria in liquid culture
minimum inhibitory concentration (MIC)
the concentration of antibiotic from the original MIC plate that shows NO GROWTH after subculture.
Minimum Bactericidal Concentration (MBC)
treatment of high-risk patients that have become infected but are asymptomatic.
Pre-emptive therapy
treatment of a symptomatic patient without further testing or confirmation of the organism.
empiric therapy
treatment once the pathogenic organism has been identified and appropriate drug identified.
definitive tx
generally a low dose therapy used as a secondary prophylaxis. Problem that caused initial infection is likely still present.
suppressive tx
what are the very drug resistant organisms
ESKAPE Enterococcus faecium Staphylococcus aureus Klebsiella pneumoniae Acinetobacter baumanni Pseudomonas aeruginosa Enterobacter species
which drug is an example of reduced drug entry into the organism via change in overall charge of membrane as a mechanism of resistance?
daptomycin
which drug is an example of increased drug export via efflux pump as a mechanism of resistance from the organism?
tetracycline
which drug is an example of changes in expression enzymes that activate the prodrug as a mechanism of resistance?
metronidazole
which drug is an example of expression of enzymes by the organism that destroy the drug as a mechanism of resistance?
aminoglycosides (streptomycin)
which drug is an example of expression beta lactamase as mechanism of resistance?
amoxicillin
which drug is an example of impaired drug binding to the original target as a mechanism of resistance?
TMP-SMX
which drug have bacteria developed new or different pathways that are not inhibited by drug?
vancomycin
what links the NAM-NAG peptidoglycan monomers b/w the NAM-NAG chains in the layer?
penicillin binding proteins
what beta lactamase inhibitor is used with PCN oftn?
clavulanic acid (augmentin)
which penicillins are broad spectrum?
amoxicillin, ampicillin
which penicillins are beta-lactamase resistant?
methicillin, nafcillin, oxacillin
which generation beta lactam antibiotics have good CNS penetration?
3rd & 4th generation cephalosporins
which generation: ceftriaxone, cefotaxime, cefdinir, cefixinme
3rd generation cephalosporin
which generation: cefepime
4th generation cephalosporin
which PBP inhibitors have less hypersensitvity?
Aztreonam
which class of drugs need to be coadministered with cilastatin to prevent inactivation in kidney?
carbapenems
which PBP inhibiting drug have GI side effects?
carbapenems
which beta lactam antibiotic does not inhibit PBP?
vancomycin
focfomycin is associated with tx of what?
UTI
which protein synthesis are associated with nephrotoxicity and ototoxicity?
aminoglycosides
erythromycin, clarithromycin, and azithromycin and associated with what subgroup?
macrolides
which class of drugs Binds to 30S (perhaps 50S as well) and blocks formation of initiation complex (Step 1)?
aminoglycosides
which class of drugs Binds to the 50S and impairs the translocation to the “P” site (Step 4)?
macrolides
which class of drugs Binds to the 30S subunit of the ribosome and prevents binding of a new aminoacyl-tRNA to “A” site (Step 2)?
tetracyclines
which protein synthesis inhibitor binds calcium and disrupts growth of teeth?
tetracyclines
which drug is assc’ed with gray baby syndrome, suppression of RBC?
chloramphenicol
which drug is very effective against resistant organisms, and works by inhibiting the formation of the ribosomal-fMet-tRNA complex?
linezolid
clindamycin is broad spectrum or narrow spectrum?
narrow spectrum
which drug inhibits topoisomerase II and IV?
ciprofloxacin and levofloxacin
of the fluroquinolones, which group has the best activity against gram positive?
group 3
which drug is used for mild-moderate C diff infxn?
metronidazole
which drug sticks to LPS and punches holes in the membrane?
polymyxin B
which types of antibiotics to use for complicated infxns?
PCN + lactamase inhibitor
what drugs do you most commonly choose from to tx MRSA?
vancomycin, linezolid, daptomycin
what is empiric tx for osteomyelitis
vancomycin, cephalosporins
what drugs should you use for septic arthritis or in general, blood infxns?
3rd-4th generation cephalosporins (Cefdinir/Ceftriaxone/Cefotaxime/Cefixime; Cefepime)
why can you use PCN or amoxicillin to tx pharyngitis?
b/c microbes are more likely to be gram+
what are the common drugs that are prescribed for UTI?
TMP SMX, fluoroquinolone
what is the broad spectrum powerhouse that is used to tx intra-abdominal infxns?
ticarcillin + clavulanate
tx of C diff?
moderate: metronidazole
severe: vancomycin
what to use for community acquired bacterial meningitis?
ceftriaxone or cefotaxime + vancomycin
what to use for neonatal meningitis (
ampiciliin+ cephalosporin +/- gentamicin
what to use for sepsis or endocarditis?
3rd/4th gen ceph + vancomycin
beside linezolid or daptomycin, what else can you use to tx resistant enterococci?
tigecycline
which beta lactams are beta lactamase resistant?
methicillin/nafcillin/oxavillin
Cefepime
Aztreonam
Carpamenems
