Antibiotic Ladder
Penicillin PCN
Gram +
Gram -
most organisms have grown resistance except syphilis.
Staph targeted drugs
MSSA
Methicillin
Clox
Ox
Nafcillin
MSSA use exclusively
MRSA
Vancomycin
- often we start with Vanco for broad spectrum,
- on test though try to see if it is indeed MRSA. IF MSSA give Nafcillin
Linezolid (PO/IV) $$$
Start at the bottom of the ladder: closest to the nodes.
Amoxicillin/Ampicillin
Gram - coverage
some Gram + if paired with
ß lactamase inhibitor
No MRSA coverage
No psudommonas
Pseudomonas
Piperacillin
ß lactamase i: Tazobactam
Pip/Tazo covers everything except MRSA
intolerant to pip/tazo
or ESBL activity
Carbapenems
Cephalosporins
Gram +
1st gen
2nd gen
Gram -
4th gen
Both Gram +/-
3rd gen
cellulitis/sx prophy
pseudomonas only
MRSA
5th gen
won't use, need mics
Be as targeted as poss/cheapest
but if you dont know what it is, go broad (pip/tazo)
Escalate quickly, deescalate slowly
Flouroquinolones
in baseball, have to get from first to second etc to get home.
Correlation of flouroquinolones to subsequent generations is that all subsequent generations contain aspects of the first
Gram -
1st gen
Cipro
Commonly for UTI
Gram +
3rd gen
Moxifloxacin
Respiratory (covers PNA)
2nd gen
Levofloxacin
can cover gram -, but too high on the ladder
More targeted anaerobe coverage
Metronidazole
Groin
Belly
Vagina
Abdomen
Anaerobes too
Clinda
anywhere else
Empiric coverage Abx regimens
CAP
HAP
Meningitis
UTI
Cellulitis
Moxifloxacin (PO/IV)
risk of fluoro resistance, try to avoid (abx stewardship)
Ceftriaxone + Azithromycin (IV, hospitals)
Azithromycin (PO, outpatient)
Culprits: MRSA and Pseudomonas
Vanc + Pip/tazo
Ceftriaxone 2g + Vanco +/- steroids +/- ampicillin
M3 students: every meningitis patient gets steroids, only immunocompromised patients get ampicillin
Amoxicillin
Nitrofurantoin
Bactrim: TMP/SMX
Ceftriaxone
If pregnant
If a woman
only if no renal failure
inpatient IV: septic and w/ bad pyelonephritis
Cipro
ambulatory pyelonephritis
suspect MRSA
Vancomycin (IV)
Clinda
Bactrim: TMP/SMX
OK to initially use
1st or 2nd gen Cephalosporin
for VISA, VRSA, and Enterococcus (VRE)
Ticarcillin
same coverage as pip/tazo
(+)
(-)