vancomycin, linezolid, and daptomycin Flashcards
vancomycin belongs in which family of drugs
glycopeptides
glycopeptides affect what types of bacteria
gram + aerobes and some anaerobes
how does vancomycin work
inhibits cell wall synthesis by binding D-alanyl-D-alanine portion of cell wall precursors to
prevent cross-linking and further elongation of peptidoglycan
how can cells confer resistance to vancomycin
i. Resistance in VRE and VRSA due to modification of D-alanyl-D-alanine
binding site of peptidoglycan
ii. Terminal D-alanine replaced by D-lactate
iii. Loss of critical hydrogen bond
iv. Loss of antibacterial activity
v. 3 phenotypes - vanA, vanB, vanC
vi. VISA – thickened cell wall
vancomycin spectrum of activity
i. Gram-positive bacteria - Methicillin-Susceptible AND MethicillinResistant
S. aureus and coagulase-negative staphylococci*
ii. Streptococcus pneumoniae (including PRSP), viridans streptococcus, Group streptococcus, Enterococcus spp.
iii. Corynebacterium, Bacillus. Listeria, Actinomyces Clostridium spp. (including C. difficile), Peptococcus, Peptostreptococcus
iv. No activity vs gram-negative organisms
clinical uses
i. Infections due to methicillin-resistant staph including bacteremia, empyema, endocarditis, peritonitis, pneumonia, skin and soft tissue
infections, osteomyelitis, meningitis
ii. Serious gram-positive infections in -lactam allergic patients
iii. Infections caused by multidrug resistant bacteria (PRSP)
iv. Endocarditis or surgical prophylaxis in select cases
v. Oral vancomycin for moderate to severe C. difficile colitis
when do you give vancomycin orally
for C. difficile (not absorbed well so it stays in the gut/colon)
Red-Man Syndrome
- due vancomycin administration
- Flushing, pruritus, erythematous rash on face, neck, and upper torso within 5 to 15 minutes of starting infusion due to Histamine release from mast cell degranulation;
- Related to RATE of intravenous infusion;
- Resolves spontaneously after discontinuation
- May lengthen infusion (over 2 to 3 hours) or pre-treat with antihistamines in some cases
Nephrotoxicity and Ototoxicity with vancomycin use
- Rare with vancomycin monotherapy, more common when administered with other nephro- or ototoxins , such as aminoglycosides
- Risk factors include renal impairment, prolonged therapy, high doses, ? high serum concentrations, use of other nephro- or ototoxins
adverse effects of vancomycin use
- red man syndrom
- nephrotoxicity and ototoxicity
- Dermatologic - rash (later onset)
- Hematologic - neutropenia and thrombocytopenia with prolonged therapy
- Thrombophlebitis – related to rate of infusion. Recommend slow infusion at least over 60 minutes.
- interstitial nephritis
old name for vancomycin
mississippi mud - had a brown color - purification lead to less adverse effects
main uses for vancomycin
MRSA and PRSP
is vancomycin bactericidal or static
time dependent bactericidal except for enterococcus which it is bacteriostatic
timing of vancomycin effects
can take days after beginning therapy to see the effects clinically
vancomycin elimination
unchanged via the kidney
1/2 life depends on renal function normally 6-8 hr but can be very very long with renal disease
vancomycin absorption and distribution
slow - peak concentrations are measured 1 hr after infusion
not absorbed well orally
widely distributed to all tissues - variable CSF penetration but increased when inflamed (used for strep pneumo menigitis)
Dalbavancin belongs to which drug group
2nd generation gycopeptide
A semisythetic lipoglycopeptide.
Dalbavancin mechanism of action
binds to C terminal D-ala-D ala interfering with cross-linkage and polymerization.
•It can attach (anchors) to the cell membrane from its lipophilic moiety, making it more potent than vancomycin*
Dalbavancin is used against
resistant gram + bacteria
MRSA, VISA
VRE with the vanB or vanC gene
MRSE (epi), streptococcus
how is dalbavancin given?
via IV with once a week dosing
half life is 9-12 days
(decrease dose with renal insufficiency)
dalbavancin side effects
Hematologic, headaches
Pruritus, anaphylaxis, skin reactions
Increased ALT
Flushing with rapid infusion (red man syndrom)
telavancin is used for
MRSA and GPOs (resistant gram + organisms
SSSI, HAP, VAP (all S. aureus