Antibiotics against Gram + Flashcards
What are the glycopeptides?
vancomycin teicoplanin dalbavancin telavancin oritavancin
What 2 infections increased use of vanco?
MRSA
PRSP
What is the MOA of vanc?
inhibits cell wall synthesis at site DIFFERENT than beta lactams (inhibits second stage)
What part of cell wall precursors does vanco bind to?
D-alany-D-alanine (prevents further cross linking and elongation)
Is vanc time or conc dependent?
TIME (bacteriocidal)
What is the MOR in vanc?
modification of D-alanyl-D-alanine binding site of PG
3 phenoytpes (vanA, B, C)
What is the spectrum of activity of vanc?
ONLY GRAM POSITIVE (MRSA, MSSA, PRSP, C. diff, corynebacterium, bacillus, listeria, actinomyces, enterococcus)
Does vanc have activity against gram negatives?
NO
What is the drug that has the opposite SOA in that it only does gram neg?
aztreonam
Do you use lean mass or total body weight for dosing vanc?
TBW (distributes to adipose too)
How long does it take to distribute vanc from plasma into tissues?
one hour
What does elimination half life depend on for vanc?
renal function (NOT removed by hemodialysis though)
When do you draw a vanc peak?
60 min post infusion
When do you use oral vancomycin?
moderate to severse C. diff colitis
What is the name of the syndrome caused when patient gets flushing immediately following bolus of vanc?
red-man syndrome (related to RATE of infusion)
resolves spontaneously
What are 2 major adverse effects of vanc?
1) nephrotoxicity
2) ototoxicity
(also dermatologic, hematologic, thrombophlebitis, interstitial nephritis)
What is the second generation glycopeptide?
dalbavancin
When is dalbavancin used?
against vanc resistant enterococcus
When and how do you give dalbavancin?
1x per week (IV)
How is dalbavancin eliminated?
kidney (NOT hemodialysis)
What was developed in response to vanc resistant bugs? (VRE, MRSA, VISA)
oxazolidinones (linezolid)
What is the MOA of linezolid?
binds to 50S subunit to inhibit prot synth (BACTERIOSTATIC)
What is the MOR of linezolid?
alterations in ribosomal binding sites
What diseases call for linezolid?
MRSA, MSSA, VRSA, PRSP, enterococcus faecium and faecalis
What gram negative diseases does linezolid treat?
NONE
What is special about the pharmacology of linezolid?
100% bioavailable regardless of route of administration (oral or IV)
How well does linezolid penetrate the CSF?
30%
Do you need to adjust linezolid for renal insufficiency?
NO (removed by HD)
What is a downside of linezolid?
EXPENSIVE (reserve use for serious infections by RESISTANT GRAM POS)
What is the significance of taking SSRIs before linezolid?
interaction (can get serotonin syndrome)
enhancement of pressor response
What is the BIGGEST adverse effect of linezolid?
thrombocytopenia (after 10-14 days)
also get peripheral neuropathy and lactic acidosis
What is Tedizolid and what is benefit of it?
bacterial SSSI
NO SSRI interaction
What is the main lipopeptide?
daptomycin (use for resistant gram positives VRE, MRSA, VISA)
What is the MOA of daptomycin?
binds to bact membrane and depolarizes it (no more prot or nuc synthesis)
What is the MOR of daptomycin?
not much
What is the spectrum of activity for daptomycin?
MRSA, MSSA, VRSA, PRSP, enterococcus faecium and faecalis
Is daptomycin conc or time dependent?
Conc
Do you change dapto dosing based on RI?
yes (renally eliminated)
Why can you not use daptomycin in the treatment on pneumonia?
inactivated by surfactant
What is the main adverse effect of daptomycin?
myopathy and CPK elevation
how do quinupristin and dalfopristin function?
protein synth inhibitors
