Community-acquired pneumonia
ICD-10 J18.9 · ICD-11 CA40.Z

Treating Community-Acquired Pneumonia in Outpatient Adults with Comorbidities

Community-acquired pneumonia (CAP) in adults managed as outpatients requires careful antibiotic selection when underlying comorbid conditions are present. These conditions affect pathogen risk and guide which regimen should be used.

Clinical Scenario This protocol applies to adults aged 18 years or older with CAP who are being managed in the outpatient setting and who have one or more of the following: chronic heart, lung, liver, or renal disease; diabetes mellitus; alcoholism; malignancy; or asplenia. This combination of CAP with underlying comorbidities defines a distinct outpatient risk group requiring a specific antibiotic approach.
Treatment Approach (Partial Overview) The recommended approach involves either combination antibiotic therapy — typically a beta-lactam paired with a second agent — or monotherapy with a respiratory fluoroquinolone. The choice between these two strategies and the complete structured regimen are detailed in the full protocol. Full options, sequencing, and duration guidance available below.
Clinical Goals Treatment aims to achieve clinical stability: resolution of vital sign abnormalities (heart rate, respiratory rate, blood pressure, oxygen saturation, and temperature), ability to eat, and normal mentation. Most patients achieve clinical stability within the first 48 to 72 hours.
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References

For outpatient adults with comorbidities such as chronic heart, lung, liver, or renal disease; diabetes mellitus; alcoholism; malignancy; or asplenia we recommend (in no particular order of preference) (Table 3):

Combination therapy: amoxicillin/clavulanate 500 mg/125 mg three times daily, or amoxicillin/clavulanate 875 mg/125 mg twice daily, or 2,000 mg/125 mg twice daily, or a cephalosporin (cefpodoxime 200 mg twice daily or cefuroxime 500 mg twice daily); AND macrolide (azithromycin 500 mg on first day then 250 mg daily, clarithromycin [500 mg twice daily or extended release 1,000 mg once daily]) (strong recommendation, moderate quality of evidence for combination therapy), or doxycycline 100 mg twice daily (conditional recommendation, low quality of evidence for combination therapy); OR

Monotherapy: respiratory fluoroquinolone (levofloxacin 750 mg daily, moxifloxacin 400 mg daily, or gemifloxacin 320 mg daily) (strong recommendation, moderate quality of evidence).

We recommend that the duration of antibiotic therapy should be guided by a validated measure of clinical stability (resolution of vital sign abnormalities [heart rate, respiratory rate, blood pressure, oxygen saturation, and temperature], ability to eat, and normal mentation), and antibiotic therapy should be continued until the patient achieves stability and for no less than a total of 5 days (strong recommendation, moderate quality of evidence).

As most patients will achieve clinical stability within the first 48 to 72 hours, a total duration of therapy of 5 days will be appropriate for most patients.

DOI: 10.1164/rccm.201908-1581ST View source ↗