. 2008 Oct 9;13(7):937–949. doi: 10.1111/j.1440-1843.2008.01409.x

Table 3.

Comparison of recommendations of recently published guidelines for empirical antimicrobial therapy of community‐acquired pneumonia in adults (from North America, UK)

Guideline	Outpatient ^†	General ward ^†	ICU/severe ^†
North American Guideline (ATS/IDSA; 2007) ³⁷	If no significant risks for drug‐resistant Streptococcus pneumoniae (DRSP) ^‡ : macrolide ^§ or doxycycline	β‐lactam (ceftriaxone, cefotaxime, ampicillin/sulbactam, ertapenem) + macrolide (can use doxycycline if macrolide not tolerated)	i.v. β‐lactam (ceftriaxone, cefotaxime, ampicillin/sulbactam) + i.v. azithromycin or i.v. fluoroquinolone ^¶ ;
	If risks for DRSP ^‡ : anti‐pneumococcal fluoroquinolone ^¶	OR	If concern for Pseudomonas (e.g., presence of structural lung disease such as bronchiectasis; advanced COPD with steroid use): anti‐pseudomonal agent (piperacillin/tazobactam, imipenem, meropenem or cefepime) + anti‐pseudomonal fluoroquinolone (ciprofloxacin or high‐dose levofloxacin); If concern for MRSA (see text): add vancomycin or linezolid (defined as severe) Co‐amoxicla or second/third generation cephalosporin + (i.v. erythromycin or clarithromycin, ± rifampin); (i.v. levofloxacin + i.v. benzylpenicillin as alternative)
	OR	OR
	High‐dose amoxicillin (3 gm/day) or high‐dose amoxicillin/clavulanate (4 gm/day) + macrolide (if amoxicillin is used and there is a concern for H. influenzae, use macrolide active for β‐lactamase producing strains, e.g. azithromycin, clarithromycin)	Anti‐pneumococcal fluoroquinolone ^¶ alone
British Thoracic Society (2004) ³²	Amoxicillin 500–1000 mg t.i.d. (Alternative—erythromycin or clarithromycin).	If admitted for non‐clinical reasons or previously untreated in the community: Amoxicillin (macrolide as alternative)
		If admitted for pneumonia and oral therapy appropriate: Amoxicillin + (erythromycin or clarithromycin); (levofloxacin or moxifloxacin as alternatives)
		If parenteral appropriate: ampicillin or benzylpenicillin + (erythromycin or clarithromycin); (Alternative: i.v. levofloxacin, note i.v. moxifloxacin is not available in UK)

^{^†}

Site of care; ICU, intensive care unit.

^{^‡}

risks: antimicrobial therapy within the past 3 months, hospitalization within the past month, alcoholism, immune‐suppressive illness (including therapy with corticosteroids), multiple medical comorbidities, exposure to a child in a day care center.

^{^§}

^§ Azithromycin, clarithromycin.

^{^¶}

^¶ Gemifloxacin, levofloxacin, moxifloxacin (gemifloxacin is only available in oral formulation).