Lecture 3: Antibiotics Part 2 Flashcards
What two amino acids connect bacterial cell walls together?
D-Ala to D-Ala
What drug class does vanco fall under?
Glycopeptide
What is the MOA of vanco and is it bactericidal or bacteriostatic?
Inhibits bacterial cell wall synthesis by binding to the D-ala D-ala chain and preventing the formation of peptidoglycan.
Results in a weakened cell wall and inability to replicate further.
It is a bactericidal drug.
How does VRE resist vanco?
Alters the binding site to D-ala-D-Lac.
What is the main hole in vanco coverage?
G-. Does not cover G-!
What are the main things vanco is good for?
MRSA!!!!!!! (IV)
C. Diff (oral)
Minor:
Listeria
Corynebacterium
Strep
Staph Pneumo
S. entercoccus
Is MRSA a G+ cocci or bacili?
G+ Cocci
Is C. Diff a G+ cocci or bacilli?
G+ Bacilli
What are the indications for vanco?
MRSA - IT IS THE INPATIENT DRUG OF CHOICE
C. diff - only for severe for refractory C. diff colitis.
How is vanco metabolized/excreted?
NO liver metabolism
Renal Excretion
Therefore adjust for renal impairment!
What pregnancy category is vanco?
Oral is B
IV is C
If someone has impaired renal function, how is dosing adjusted?
Less frequent dosing intervals.
What two things about a person determine their general vanco dosing?
CrCl
Total Body weight
How is vanco monitoring done?
Severe MRSA and other severe infections use AUC calculations.
All other normal infections are trough level.
When is a loading dose indicated for vanco?
Severe infections.
Why does vanco need monitoring?
It has a narrow therapeutic window.
When do I measure a trough level for vanco?
30 mins prior to next infusion AFTER SS is reached.
How many doses of vanco does it typically take to reach SS?
4 doses.
When do I get peak levels of vanco?
1-2 hours post dose.
What is the main adverse effect of vanco that is not life-threatening?
Hyperemia/red-man syndrome.
What is hyperemia caused by and how do I treat it?
It is pruritis with erythematous rash of the face, neck, and upper torso.
Caused by rapid infusions or high doses.
Treated by slowing the infusion and/or pretreating with an antihistamine.
What is a deadly adverse effect of vanco and what demographics are most susceptible?
Nephro and ototoxicity with high daily doses.
Occurs most frequently in renally impaired or elderly pts.
Occurs even more frequently when used with an aminoglycoside.
Requires monitoring of BUN/Cr and s/s of auditory dysfunction.
What are some alternatives to vanco?
For MRSA:
Telavancin, Dalbavancin, and Oritavancin are similar.
Daptomycin work EXCEPT if MRSA is in the lungs. (ALSO GOOD FOR VRE)
Linezolid: oral (uncommon)
Note:
All of these work vs VRE also except tela and dalba.
What are the 4 main aminoglycosides?
Gentamicin
Tobramycin
Amikacin
Streptomycin
Note:
micin
mycin
cin