This patient should begin outpatient treatment with a respiratory fluoroquinolone, such as levofloxacin; a reasonable alternative would be an oral β-lactam antibiotic in combination with a macrolide or doxycycline. Initial assessment of patients with community-acquired pneumonia (CAP) begins with establishing an appropriate venue of care. Clinical decision tools, such as the modified CRB-65, which omits the blood urea nitrogen (BUN) component of the original CURB-65 (confusion, BUN [>20 mg/dL (7.14 mmol/L)], respiration rate [≥30/min], blood pressure [systolic <90 mm Hg, diastolic <60 mm Hg], and age ≥65 years), can be used in office-based settings to expedite determining the need for hospitalization. This patient has no confusion, is not hypotensive, and does not have significant tachypnea (respiration rate is <30/min), so his CRB-65 score is 0 and he does not require hospitalization. Empiric antibiotic therapy is focused toward the most likely organisms, modified by specific risk factors in a particular patient. Patients with no risk factors for resistant Streptococcus pneumoniae are candidates for treatment with either a macrolide or doxycycline. However, in patients with increased risk for resistance (age >65 years, recent [within the past 3-6 months] antimicrobial therapy [with a β-lactam, macrolide, or fluoroquinolone antibiotic], alcoholism, immunosuppression, and certain medical comorbidities [COPD, chronic liver or kidney disease, cancer, diabetes, functional or anatomic asplenia, chronic heart disease]), therapy with a respiratory fluoroquinolone or a β-lactam with a macrolide or doxycycline is appropriate. Because this patient has COPD, his risk for resistant S. pneumoniae is increased, and expanded antibiotic coverage is indicated instead of macrolide monotherapy (such as azithromycin).

For patients requiring hospital ward admission for treatment, an empiric regimen of an intravenous β-lactam with a macrolide or doxycycline (such as ampicillin-sulbactam and doxycycline) or a respiratory fluoroquinolone is recommended. However, this patient does not have a clear indication for hospital admission for treatment.

For patients with CAP requiring ICU admission, treatment with an intravenous β-lactam plus either azithromycin or a fluoroquinolone (such as ceftriaxone and azithromycin) is indicated. Because this patient does not require hospitalization or intensive care, this would not be an appropriate empiric treatment regimen.