According to the IDSA/ATS guidelines, in the
outpatient setting, the recommended empirical
treatment is a macrolide for previously healthy
patients who have not used antimicrobials
within the previous 3 months. However, in
some countries macrolide-resistant S. pneumoniae
are frequent [Jones et al. 2010; European Centre
for Disease Prevention and Control,
20052013]. A respiratory fluoroquinolone or a
beta-lactam plus a macrolide are recommended
for patients with comorbidities. In hospitalized
patients with nonsevere CAP, the recommendation
is a respiratory fluoroquinolone or a
beta-lactam plus a macrolide. In severe CAP, a
combination of antibiotics is usually recommended.
A beta-lactam plus either azithromycin
or a respiratory fluoroquinolone are preferred. In
patients with predisposing factors for P. aeruginosa
or other Gram-negative bacilli an antipneumococcal,
antipseudomonal beta-lactam plus
either a quinolone or an aminoglycoside and
azithromycin should be considered [Mandell
et al. 2007]. If MRSA is considered as a possible
causative organism, guidelines recommend
adding vancomycin or linezolid.