Dr. Cluck Clinical Application Gram(+) Flashcards
(40 cards)
What is required for every patient on VNC?
Therapeutic Drug Monitoring
AUC or through-based monitoring
What are other nephrotoxic agents interacting with VNC?
Aminoglycosides
Pip-Tazo
Adverse effects of VNC
-possible Nephrotoxicity/Ototoxicity
-VNC Infusion Reaction (painful)
What is the VNC Infusion Reaction?
-Histamin-related reaction (rash)
-IV administered too quickly
-Normal infusion rate 1g/hr
What is the disadvantage of the VNC + Pip-Tazo combination?
-Synergistic Nephrotoxicity (both are nephrotoxic)
still a common combo
Pip-Tazo: for gram (-) coverage (also Pseudo and anaerobes)
VNC: mainly for MRSA, Gram (+) coverage
Which drug is appropriate to substitute with Pip-Tazo?
-Cefepime(4) for Gram(-) also: Pseudomonas, Gr(+), MSSA
-but no anaerobes coverage (anaerobes are often bystanders)
Spectrum of Activity for VNC
EXAM!!!
-Only Gram (+)
-MRSA
-Streptococcus (not to best option, there are better drugs -> ß-lactams work well)
-Enterococci
Why is VNC not the best choice for Streptococcus?
-ß-lactams cover Streptococcus well
-It damages the kidneys
How would C. diff be treated with VNC?
-PO (bc the absorption is weak and it works in the gut where C. Diff is present)
-IV has no activity
Drug Class of Zyvox
Linezolid
-Gram (+) coverage
-MRSA
-Streptococcus (fine for superficial, skin tissue)
-VRE
-Hepatic eliminated (metabolites can accumulate)
Why are Linezolids used for superficial infections rather than invasive (Bacterimia, CNS) infections?
It is bacteriostatic
MOA of Linezolids?
Binds to 50S and block 50S + 30S (70S) formation
Drug formulations of Zyvox
-IV and PO (2x daily)
-100% IV to PO conversion
Adverse effects of Linezolid
!!!
-Myelosuppression (bone marrow) after 14 days of use (dip in platelets)
-lactic acidosis, teeth coloring (not seen by Dr. Cluck)
-optic neuritis
-weak MOA inhibitor
! -interacts with SSRI and other drugs with serotonergic activity
Cubicin
!!!
-Daptomycin
-IV Only
-Gram (+), MRSA, Strepto, VRE - same as VNC
-cannot treat pneumonia (inactivated by pulmonary surfactant) !!!
-drug interaction with statins !!!
Adverse effects of Daptomycin
!!!
-Eosinophilic pneumonia (hypersensitivity)
-if used with statins: Myopathy
-> Monitor weekly CPK (creatine phosphate kinase) !!
3 big drugs for invasive Gram (+) infections
-VNC (DOC for MRSA)
-Linezolid (also MRSA)
-Daptomycin (also MRSA)
What is VISA?
-Subpopulation that can not be treated with VNC
-treat with Daptomycin, Linezolid, or Ceftaroline(5)
-VNC intermediate Staph aureus (more often than VRSA)
(VRSA - VNC resistant Staph aureus)
-cell wall starts to thicken, tolerance to VNC
When is Linezold preferred over VNC (Gold-standard)?
-MRSA-Pneumonia
-bc VNC is weight-based dosing - it doesn’t fit all
-clinical trial: it took 9 days to reach therapeutic level vs. linezolid is therapeutic right away
Cleocin
-Clindamycin (MOA like erythromycin)
-IV, PO, supp., topical
-probably 1:1 IV-PO conversion, but the GI doesn’t tolerate high doses
-lincosamide antibiotic
-share MOA and MOR with macrolides
Spectrum of activity
!!!
-Excellent anaerobic
-mouth and respiratory tract (except CNS)
-good Gram (+) except Entercocci
-Clinically used for MRSA (Peds) !!
-cause C. Diff !!
Thumb of Rule for Action site of Clindamycin
above the diaphragm use Clindamycin
below the diaphragm use metronidazole
kind of TRUE
Rifadin (Rifampin)
-Rifamycin derivative
-IV and PO, 1:1 conversion, but high doses are not well tolerated, so given in 2 doses
-check for DDI: CYP induction !!
-red dye of fluids !! (like metronidazole) !!
Don’t use it as MONOTHERAPY: adjunct ONLY: bc resistance develops quickly !!
Why should Rifampin be used with caution?
-check for DDI: CYP induction: drugs are getting way more effectively cleared by CYP enzymes (there are more enzymes, channels, and transporters affected) !!!
