Term
prevents enzymatic dephosphorylation of bacterial cell wall building blocks (binds to a substrate, not the enzyme)
acts during the SECOND STAGE of cell wall synthesis
[image]
metal is needed (Zn)
resistance: rare |
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Definition
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Term
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Definition
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Term
restricted for topical use
nephrotoxic
not absorbed from the GI tract |
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Definition
| pharmacology of bacitracin |
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Term
binds to bacterial membranes which interrupts protein synthesis, DNA synthesis, and RNA synthesis
depolarization, loss of membrane potential, and cell death
no cross-resistance with other antibiotics (novel MOA) |
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Definition
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Term
not known
resistance develops very slowly in the clinic |
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Definition
| mechanism of resistance to daptomycin |
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Term
poorly absorbed
only administered IV
reversibly bound to albumin
80% of the dose is recovered in urine
it does not inhibit nor induce CYPs
potential risk for nephrotoxicity and myopathy (aminoglycosides or statins) |
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Definition
| pharmacology of daptomycin |
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Term
binds reversibly to the isoleucyl tRNA synthetase
protein synthesis inhibitor
no cross resistance
most active at acidic pHs (drug is in neutral form) |
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Definition
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Term
| resistance due to mutation of the host gene encoding iLeu-tRNA |
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Definition
| bacterial resistance to mupirocin |
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Term
active against many gram + and some gram -
good for MSSA and MRSA
bacteriostatic at low concentrations and bactericidal at high concentrations |
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Definition
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Term
systemic absorption is minimal
rapidly metabolized to inactive monic acid = rupture of the ester bond
[image] |
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Definition
| pharmacology of mupirocin |
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Term
binds exclusively to the 50s subunit of the ribosome
it interferes with A site and P site substrate binding |
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Definition
MOA of clindamycin (lincosamide)
[image] |
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Term
macrolide resistance due to ribosomal methylation may produce resistance to clindamycin (cross resistance)
not susceptible to drug efflux resistance
specific resistance: enzymatic modification of the drug (phosphorylation and nucleotydilation) of the hydroyl at position 3
[image] |
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Definition
| bacterial resistance to clindamycin |
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Term
broad spectrum
more active than erythromycin and clarithromycin against anaerobic bacteria |
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Definition
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Term
nearly completely absorbed by oral administration
clindamycin is widely distributed (not in the CSF)
only 10% is excreted unaltered
N-demethylation and oxidation of the thio to sulfoxide
[image] |
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Definition
| pharmacology of clindamycin |
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Term
protein synthesis inhibitors (50s), they inhibit the early stages of protein synthesis
dalfopristin binds binds at the same site as macrolides and quinopristin binds at a near by site
dalfopristin inhibits the peptide bond formation by weakening the binding of the peptidyl and aminoacyl tRNA or by direct interference of the peptidyl transferase reaction
quinopristin sterically hinders the growth of the nascent peptide during early stages of protein synthesis
synergism |
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Definition
| MOA of quinopristin/dalfopristin |
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Term
resistance to dalfopristin: active efflux due to a transporter; inactivation enzyme; methylation that prevents binding
resistance to quinopristin: rRNA methylation catalyzed by a 23s rRNA methylase = cross resistance with clindamycin and macrolides; elimination of the hexadepsipepside ring by specific lyases |
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Definition
| resistance to dalfopristin and quinopristin |
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Term
gram + and anaerobes
DOES NOT WORK ON GRAM - b/c they are too big to pass through porin channels |
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Definition
| spectrum of dalfopristin/quinopristin |
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Term
administered only by IV infusion
hepatic metabolism by conjugation
renal elimination of the active compound is minimal
quinopristin/dalfopristin inhibit CYP3A4 |
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Definition
| pharmcology of quinopristin/dalfopristin |
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Term
inhibits the 50s subunit of the ribosome
protein synthesis inhibitor |
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Definition
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Term
no cross resistance
resistance due to mutations on the 23s rRNA |
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Definition
| bacterial resistance to linezolid |
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Term
well absorbed after oral administration
30% bound to protein and widely distributed
metabolized by nonenzymatic oxidation
80% appears in the urine
oxidation product accumulate in the kidneys |
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Definition
| pharmacology of linezolid |
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Term
for the treatment of infections by VRE, nosocomial pneumonia, community acquired pneumonia, MSSA, MRSA
linezolid should be reserved as an alternative agent for treatment of infections caused by multiple drug resistant strains |
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Definition
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Term
| potent inhibitor of anaerobes and protozoa |
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Definition
| spectrum of metronidazole |
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Term
the reduced form of metronidazole is active = PRODRUG
metronidazole disrupts bacterial helical DNA
resistance = acquired
may have insufficient absorption or transport to site of infection |
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Definition
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Term
cationic surface active compounds
the fatty acid penetrates into the hydrophobic region of the outer membrane
the ammonium groups interact with the lipopolysaccharides and phospholipids
competitive displacement of cations (Ca and Mg)
disrupts membrane organization |
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Definition
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Term
| acts exclusively against gram - aerobic bacilli |
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Definition
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Term
| neurotoxicity and nephrotoxicity b/c polymixins are NON-SELECTIVE (they can also disrupt our cell membranes) |
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Definition
| side effects of polymixins |
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Term
protein synthesis inhibitor
binds to the peptidyltransferase center of the 50s ribosomal unit |
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Definition
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Term
| enzymatic inactivation and active efflux |
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Definition
| bacterial resistance of chloramphenicol |
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Term
blood dyscrasias are seen in patients
panytopenia - fatal (known as aplastic anemia)
irreversible inhibition of hematopoiesis
gray syndrome: newborns (undeveloped liver glucuronidation)
very toxic, no longer marketed in the US |
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Definition
| toxicity of chloramphenicol |
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