Glycopeptide Antibiotics Flashcards
What are the 5 glycopeptide antibiotics?
Vancomycin Teicoplanin Dalbavancin Telavancin Oritavancin
Vancomycin Mechanism of Action
Inhibit bacterial cell wall synthesis by binding the D-alanyl-D-alanine portion of cell wall precursors. Prevents cross linking and elongation of peptidoglycan
Vancomycin has ____-dependent ________ activity
Time dependent bactericidal activity
Very slow…may take days to show improvement
Vancomycin Mechanisms of Resistance
- Change the binding site of peptidoglycan (alter D-alanyl-D-alanine binding site)
- 3 phenotypes of resistance: vanA, vanB, vanC
- Could thicken cell wall for intermediate susceptbility
Vancomycin Spectrum of Activity
Gram Positives only! MSSA, MRSA Coagulase negative Staph Enterococcus (Not VRE) Strep - Group, Viridians, PRSP Corynebacterium, Clostridium (including C diff) Bacillus, Listeria, Actinomyces
Vancomycin Absorption
Mostly given IV due to poor oral absorption. However, oral administration is used in C diff infections
Vancomycin Distribution
Wide distribution in body tissues, fluids, and adipose
Variable penetration into CSF
May be used for infections anywhere in the body
Vancomycin Elimination
Renal
Elimination half life depends on renal function, so change dosing based on renal insufficiency.
When is it best to measure serum concentrations of vancomycin (trough and peak)?
Measure peak 60 min after end of infusion.
Measure trough 30 min before next infusion.
Explain symptoms and etiology of Red Man’s Syndrome
Flushing, puritis, erythematous rash on face, neck, torso within 15 min of vancomycin infusion
Due to a histamine release
Resolves spontaneously
Related to the rate of infusion of a drug
Vancomycin Adverse Effects
Nephrotoxicity and Ototoxicity
-more common when used with aminoglycosides or in patients with preexisting renal impairment
Neutropenia, thrombocytopenia
Rash
Dalbavancin Mechanism of Action
2nd gen glycopeptide
Similar to vancomycin, binds the D-alanyl-D-alanine complex to inhibit cross linking of peptidoglycan
-Lipid moiety anchors Dalbavancin to the cell membrane, causing MORE POTENT AND BACTERICIDAL activity
Dalbavancin Spectrum of Action
Gram Positive organisms, particularly resistant Gram +s
MRSA
VISA
VRE with vanB or vanC gene
Dalbavancin Dosing
Once weekly dosing (IV infusion)
Adjust dosing in renal insufficiency
Telavancin Spectrum of Activity
Lipoglycopeptide
Used for Gram Positive organisms
Used for Staph aureus infections
