Patient group	Recommended initial therapy
Previously healthy outpatients with no antibiotic use in past three months	Macrolide (azithromycin [Zithromax]) or doxycycline
Outpatients with comorbidities* or antibiotic use in past three months†	Preferred36,37: Respiratory fluoroquinolone (levofloxacin [Levaquin], gemifloxacin [Factive], or moxifloxacin [Avelox])
	Alternative: Beta-lactam antibiotic (high-dose amoxicillin, amoxicillin/clavulanate [Augmentin], cefuroxime [Ceftin], or cefpodoxime) plus a macrolide‡
Inpatients, non-ICU§	Preferred36,37: Respiratory fluoroquinolone
	Alternative: Beta-lactam antibiotic plus a macrolide
Inpatients, ICU	Beta-lactam antibiotic (ceftriaxone, cefotaxime [Claforan], or ampicillin/sulbactam [Unasyn]), plus a macrolide alone or a macrolide and a respiratory fluoroquinolone||¶
Special considerations
Risk factors for Pseudomonas species	Beta-lactam antibiotic (piperacillin/tazobactam [Zosyn], cefepime, imipenem/cilastatin [Primaxin], meropenem [Merrem IV], or doripenem [Doribax]), plus either ciprofloxacin or levofloxacin
		or
	The above beta-lactam antibiotic plus an aminoglycoside and azithromycin
		or
	The above beta-lactam antibiotic plus an aminoglycoside and an antipneumococcal respiratory fluoroquinolone
Risk factors for methicillin-resistant Staphylococcus aureus	Vancomycin, linezolid (Zyvox), or ceftaroline (Teflaro)38
Influenza virus	Oseltamivir (Tamiflu) or zanamivir (Relenza)