Table 3.

Comparison of recommendations of guidelines for empirical antimicrobial therapy of community-acquired pneumonia in adults

	Outpatient	Non-ICU inpatient	ICU (severe)
North American Guidelines (synthesis from IDSA, Canadian guidelines,†CDC, 2000; American Thoracic Society 2001)5, 6, 7, 8, 9	If no significant risks for DRSP*: Macrolide or doxycycline If risks for DRSP*: Antipneumococcal fluoroquinolone§ or	β lactam (ceftriaxone, cefotaxime, ampicillin/sulbactam) plus macrolide‡ (can use doxycycline if macrolide not tolerated) or	β lactam (ceftriaxone, cefotaxime, ampicillin/sulbactam, piperacillin/tazobactam) plus macrolide‡ or fluoroquinolone§ (if β lactam allergy, use fluoroquinolone§ plus clindamycin)
	High-dose amoxicillin (3 g/day) or amoxicillin/clavulanate plus macrolide (if amoxicillin is used and there is a concern for H influenzae, use agent active for β lactamase producing strains‡	Antipneumococcal fluoroquinolone§ alone	In the case of structural lung disease: antipseudomonal agent (piperacillin/tazobactam, carbapenem, or cefepime) plus antipseudomonal fluoroquinolone (high dose ciprofloxacin or levofloxacin)
Japanese Respiratory Society (2000)12	(Specified as mild or moderate pneumonia)	(Specified as severe pneumonia)	Not specified Consider as for other inpatients, for elderly, or underlying illness
	When bacterial pneumonia suspected: a penicillin type (with β lactamase inhibitor (orally), or penicillin type (injection) Or cepham type drug When atypical pneumonia suspected: macrolide or tetracycline	For younger patients without underlying illness: injection use fluoroquinolone For elderly or underlying illness: Carbapenem plus [tetracycline or macrolide]; or third generation ceph plus clindamycin plus [tetracycline or macrolide]
British Thoracic Society (2001)15	Amoxicillin 500–1000 mg thrice daily (alternatively, 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 plus [erythromycin or clarithromycin]; (alternative–antipneum fluoroquinolone) If parenteral appropriate: (ampicillin or benzylpenicillin) plus (erythromycin or clarithromycin) (alternative–IV levofloxacin)	(Defined as severe) Co-amoxiclav or 2nd/3rd generation cephalosporin plus [iv erythro or clarithro, +/- rifampicin] (Fluoroquinolone with enhanced pneumococcal activity plus benzylpenicillin as alternative)

^*ICU= intensive care unit. DRSP=drug resistant S pneumoniae. β lactam treatment within the past 3 months, admission within the past month, alcoholism, immune-suppressive illness (including treatment with corticosteroids), medical comorbidities, exposure to a child in a day-care centre.

^†Canadian Infectious Disease Society and Canadian Thoracic Society.

^‡If chronic obstructive pulmonary disease, use a macrolide active against βlactamase producing H influenzae (ie, azithromycin, clarithromycin).

^§Gatifloxacin, levofloxacin, moxifloxacin.