10
Treatment
Table 3. Empiric Treatment Options for Suspected
MRSA/Pseudomonas/Gram-negative VAP
A B C
Gram-Positive
Antibiotics
With MRSA
Activity
Gram-Negative Antibiotics
With Antipseudomonal
Activity:
β-Lactam–Based Agents
Gram-Negative Antibiotics With
Antipseudomonal Activity:
Non-β-Lactam–Based Agents
Glycopeptides
a
Antipseudomonal
penicillins
b
Fluoroquinolones
Vancomycin
15 mg/kg IV
q8–12h (consider
a loading dose of
25–30 mg/kg × 1
for severe illness)
Piperacillin-tazobactam
4.5 g IV q6h
b
• Ciprofloxacin 400 mg IV q8h
• Levofloxacin 750 mg IV q24h
OR OR OR
Oxazolidinones Cephalosporins
b
Aminoglycosides
a, c
Linezolid 600 mg
IV q12h
• Cefepime 2 g IV q8h • Amikacin 15–20 mg/kg IV q24h
• Ceftazidime 2 g IV q8h • Gentamicin 5–7 mg/kg IV q24h
• Tobramycin 5–7 mg/kg IV q24h
OR OR
Carbapenems
b
Polymyxins
a,e
• Imipenem 500 mg IV q6h
d
• Colistin 5 mg/kg IV × 1
(loading dose) followed by
2.5 mg × (1.5 × CrCl + 30)
IV daily, divided q12h
(maintenance dose)
• Meropenem 1 g IV q8h
OR
Monobactams
f
• Polymyxin B 2.5–3.0 mg/kg/d
divided in 2 daily IV doses
Aztreonam 2 g IV q8h
Choose one Gram-positive option from column A, one Gram-negative option from column
B, and one Gram-negative option from column C. Note that the initial doses suggested in
this table may need to be modified for patients with hepatic or renal dysfunction.
a
Drug levels and adjustment of doses and/or intervals required.
b
Extended infusions may be appropriate. Please see Optimization section.
c
On meta-analysis, aminoglycoside regimens were associated with lower clinical response rates with
no differences in mortality.
d
e dose may need to be lowered in patients weighing <70 kg to prevent seizures.
e
Polymyxins should be reserved for settings where there is a high prevalence of multidrug resistance
and local expertise in using this medication. Dosing is based on colistin-base activity (CBA) — for
example, one million IU of colistin is equivalent to about 30 mg of CBA, which corresponds to
about 80 mg of the prodrug colistimethate. Polymyxin B (1 mg = 10,000 units).
f
In the absence of other options, it is acceptable to use aztreonam as an adjunctive agent with another
β-lactam–based agent because it has different targets within the bacterial cell wall.
