Term
vacomycin and teicoplanins are natural antibiotics
effective in the treatment of Gram + bacteria (narrow spectrum)
teicoplanins is a complex of 5 related molecules with similar antibiotic potency
structure of vancomycin:
[image]
7 peptides forming cross-linked bridges (making the molecule rigid)
structure of teicoplanin:
[image]
MAJOR DIFFERENCE IS RESIDUE 1: N-METHYL LEUCINE
[image] |
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Definition
| characteristics of vancomycin and teicoplanins |
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Term
vancomycin binds reversible to the D-Ala-D-Ala dipeptide segment of the muramyl pentapeptide (building block)
ACT DURING STAGE 2 OF CELL WALL SYNTHESIS which inhibits all reactions in stage 3 (transglycoslyation, transpeptiation)
[image]
they prevent the interaction of the building blocks with tranglycosylases and transpeptidases enzymes
5 hydrogen bonds
glypeptides (vancomycin) do not penetrate into the cytoplasm: act from OUTSIDE THE CELL
they prevent the interaction of the dipeptide with the transglycoslase
it is thought to be a steric hindrance
[image]
dimerization of vancomycin: hydrogen bonding between 2 vancomycin molecules makes the interaction to the building blocks even stronger.
[image]
teicoplanins do not form a dimer, but have stronger binding affinity than vancomycin |
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Definition
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Term
vancomycin resistant enterococci (VRE)
acquired resistance: terminal dipeptide replaced (building block does not have the D-Ala-D-Ala terminal)
intrinsic resistance: found in E. faecalis and E. faecium. different metabolic pathway for the biosynthesis of the peptidoglycans (building blocks). not an adaptation. |
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Definition
| mechanism of bacterial resistance to vancomycin |
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Term
poorly absorbed in the GI tract
IV administration
wide distribution
meningitis treatment
serum protein binding (55%)
excreted by glomerular filtration |
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Definition
| pharmacology of vancomycin |
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Term
urticarial reactions (red-neck or red-man syndrome
co-administration with antihistamines
phlebitis
ototoxicity: sometimes permanent, related to excessively high plasma concentrations
nephrotoxicity: unusual if appropriate doses are used |
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Definition
| adverse effects of vancomycin |
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Term
high affinity binding to the D-Ala-D-Ala terminus
bactericidal against susceptible strains
active against methicillin sensitive and MRSA
resistance can emerge during therapy
mechanism of resistance is very similar to vancomycin |
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Definition
| MOA and resistance of teicoplanin |
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Term
teicoplanin can be administered safely via IM
highly bound to plasma proteins
long serum elimination half life
dosage must be adjusted for patients with renal insufficiency |
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Definition
| absorption, distribution, and excretion of teicoplanin |
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Term
| vancomycin b/c of leucine side chain |
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Definition
analog of vancomycin or teicoplanin?
[image] |
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Term
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Definition
analog of vancomycin or teicoplanin?
[image] |
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Term
vancomycin
telavancin inhibits bacterial cell wall synthesis in the same way as vancomycin
also binds the bacterial membrane and disrupts membrane barrier function
approved for the treatment of skin and skin structure infections
associated with reversible renal dysfunction |
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Definition
analog of vancomycin or teicoplanin?
[image]
MOA |
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