1. Previously healthy and no antibiotics in past 3 months
   • A macrolide (clarithromycin [500 mg PO bid] or azithromycin [500 mg PO once, then 250 mg qd]) or
   • Doxycycline (100 mg PO bid)
2. Comorbidities or antibiotics in past 3 months: select an alternative from a different class
   • A respiratory fluoroquinolone (moxifloxacin [400 mg PO qd], gemifloxacin [320 mg PO qd], levofloxacin [750 mg PO qd]) or
   • A β-lactam (preferred: high-dose amoxicillin [1 g tid] or amoxicillin/clavulanate [2 g bid]; alternatives: ceftriaxone [1-2 g IV qd], cefpodoxime [200 mg PO bid], cefuroxime [500 mg PO bid]) plus a macrolide^a
3. In regions with a high rate of “high-level” pneumococcal macrolide resistance,^b consider alternatives listed above for pts with comorbidities.

• A respiratory fluoroquinolone (e.g., moxifloxacin [400 mg PO or IV qd] or levofloxacin [750 mg PO or IV qd])
• A β-lactam^c (e.g., ceftriaxone [1-2 g IV qd], ampicillin [1-2 g IV q4-6h], cefotaxime [1-2 g IV q8h], ertapenem [1 g IV qd]) plus a macrolide^d (e.g., oral clarithromycin or azithromycin [as listed above] or IV azithromycin [1 g once, then 500 mg qd])

• A β-lactam^e (e.g., ceftriaxone [2 g IV qd], ampicillin-sulbactam [2 g IV q8h], or cefotaxime [1-2 g IV q8h]) plus either azithromycin or a fluoroquinolone (as listed above for inpatients, non-ICU)

IfPseudomonasis a consideration:

• An antipseudomonal β-lactam (e.g., piperacillin/tazobactam [4. 5 g IV q6h], cefepime [1-2 g IV q12h], imipenem [500 mg IV q6h], meropenem [1 g IV q8h]) plus either ciprofloxacin (400 mg IV q12h) or levofloxacin (750 mg IV qd)
• The above β-lactams plus an aminoglycoside (amikacin [15 mg/kg qd] or tobramycin [1. 7 mg/kg qd]) plus azithromycin
• The above β-lactams^f plus an aminoglycoside plus an antipneumococcal fluoroquinolone

If CA-MRSA is a consideration:

• Add linezolid (600 mg IV q12h) or vancomycin (15 mg/kg q12h initially, with adjusted doses)