antibioticsbooks

94 PART 2 Antibacterial Drugs
Mechanism of Action
Glycopeptides bind to terminal d-ala-d-ala chains
on peptidoglycan in the cell well, preventing further
elongation of peptidoglycan chains. Telavancin has a
second mechanism where the drug interferes with the
cell membrane also, disrupting membrane function.
Spectrum
Good: MSSA, MRSA, streptococci, Clostridium
difficile
Moderate: enterococci
Poor: anything Gram-negative
Adverse Effects
Infusion-related reactions: A histamine-mediated
reaction called red man syndrome is classically
associated with vancomycin. When it occurs,
the patient may feel warm, flushed, and may
be hypotensive. This reaction can be prevented
by slowing the infusion rate and is not a true
allergy. Antihistamines can also ameliorate
the reaction. Because the core structure of telavancin
is essentially vancomycin, it may cause
this reaction as well.
Ototoxicity: Vancomycin has historically been considered
an ototoxic drug, but evidence linking
it with this toxicity is unclear.
Renal: Nephrotoxicity is an adverse effect classically
assigned to vancomycin. Although the
historical evidence linking this with vancomycin
is poor, recent studies have shown that it
may be nephrotoxic in higher doses, including
the higher doses that are commonly used
to treat MRSA infections in the twenty-first
century. The early formulation of vancomycin