Gram Positive Antibiotics Flashcards
What are the glycopeptides?
• Vancomycin • Teicoplanin • Dalbavancin • Telavancin • Oritavancin
What is the MOA of vancomycin?
Inhibits bacterial cell wall synthesis at a site different than β-lactams at the second stage of synthesis.
Binds firmly to D-alanyl-D-alanine portion of cell wall precursors to prevent cross-linking and further elongation of peptidoglycan; weakens cell wall.
What is the pharmokinetic activity of vancomycin?
Time-dependent bactericidal activity (kills bacteria slowly)
Bacteriostatic VS enterococcus
How are VRE and VRSA resistant to vancomycin?
Modification of D-alanyl-D-alanine binding site of peptidoglycan
! Terminal D-alanine replaced by D-lactate
! Loss of critical hydrogen bond
! Loss of antibacterial activity
How is VISA (Vancomycin Intermediate S. aureus) resistant to vancomycin?
Thickened cell wall
What is the spectrum of vancomycin activity?
Gram-positive bacteria
! MSSA/MRSA
! Coagulase-negative staphylococci*
! Streptococcus pneumoniae (including PRSP), viridans streptococcus, Group streptococcus
! Enterococcus spp.
! Corynebacterium, Bacillus. Listeria, Actinomyces
! Clostridium spp. (including C. difficile), Peptococcus, Peptostreptococcus
NO GRAM-NEGATIVE ACTIVITY
How is vancomycin administered?
Must be IV
Oral only for C. difficile
What is the elimination of vancomycin dependent upon?
Elimination half-life depends on renal function
Vancomycin SE
Red-Man Syndrome
! Flushing, pruritus, erythematous rash on face, neck, and upper torso within 5 to 15 minutes of starting infusion (His release)
! Related to RATE of intravenous infusion; doses should be infused over at least 60 minutes
Otoxicity
Nephrotoxicity
What is the MOA of dalbavancin?
D-ala D-ala binding, inhibiting cross-linkage similar to vancomycin. However, it has a lipid moiety that anchors to cell membrane.
More potent and cidal than vancomycin
What is the spectrum of dalbavancin activity?
MRSA VISA vanB and vanC VRE (NOT vanA though) Bacillus, Listeria, Corynebacter MRSE
How is dalbavancin administered?
IV only
What are the main uses for telavancin?
Complicated SSSI
Pneumonia (hospital acquired)
What are the main uses for oritavancin?
MSSA, MRSA, Enterococcus, Strep possible Bacillus anthracis
What is the MOA of oritavancin?
Same as vancomycin but it also disrupts the cell membrane