What is the first-line treatment for a patient with community-acquired pneumonia (CAP), presenting with shortness of breath (SOB), cough, wheezing, and chills, and an allergy to non-steroidal anti-inflammatory drugs (NSAIDs)?

First-Line Treatment for Community-Acquired Pneumonia

For this patient with mild right infrahilar infiltrate CAP and NSAID allergy, treat with amoxicillin 1 gram three times daily for 5 days, or alternatively doxycycline 100 mg twice daily if amoxicillin is not tolerated. 1

Treatment Selection Algorithm

Step 1: Assess Severity and Comorbidities

• This patient presents with mild CAP (outpatient-appropriate based on CXR showing only mild infiltrate) 1
• No mention of comorbidities such as chronic heart/lung disease, diabetes, alcoholism, malignancy, or asplenia 1
• NSAID allergy is irrelevant to antibiotic selection—NSAIDs are not part of CAP treatment 1

Step 2: First-Line Antibiotic Selection for Patients Without Comorbidities

Primary recommendation: Amoxicillin 1 gram orally three times daily 1

• High-dose amoxicillin has demonstrated efficacy for CAP despite lack of atypical coverage 1
• Long track record of safety and effectiveness against Streptococcus pneumoniae, the most common CAP pathogen 1, 2

Alternative option: Doxycycline 100 mg orally twice daily 1

• Provides broader spectrum including atypical organisms 1
• Consider 200 mg first dose to achieve adequate serum levels more rapidly 1

Macrolide option (azithromycin 500 mg day 1, then 250 mg daily) ONLY if local pneumococcal resistance is <25% 1

• This option should be used cautiously due to increasing resistance patterns 1

Step 3: Duration of Therapy

Treat for minimum 5 days, continuing until clinical stability is achieved 1

• Clinical stability criteria include: normalized vital signs (heart rate, respiratory rate, blood pressure, oxygen saturation, temperature), ability to eat, and normal mentation 1
• Most patients achieve clinical stability within 48-72 hours 1

Step 4: When to Consider Alternative Regimens

If patient had comorbidities (which this patient does not), use combination therapy: 1

• Amoxicillin/clavulanate 875 mg/125 mg twice daily PLUS azithromycin or doxycycline 1
• OR respiratory fluoroquinolone monotherapy (levofloxacin 750 mg daily or moxifloxacin 400 mg daily) 1

Critical Pitfalls to Avoid

Do not use fluoroquinolones as first-line in uncomplicated CAP without comorbidities 1

• Reserve fluoroquinolones for patients with comorbidities or recent antibiotic exposure 1
• Fluoroquinolones carry risks of serious adverse events including QT prolongation, tendon rupture, and peripheral neuropathy 1, 3

Do not assume all CAP requires atypical coverage 1

• Studies show high-dose amoxicillin is effective despite lack of atypical coverage 1
• Only 15% of hospitalized CAP patients with identified pathogens have S. pneumoniae, while up to 40% have viral etiologies 2

Mucinex (guaifenesin) does not treat pneumonia 1

• This patient needs antibiotic therapy, not just symptomatic treatment 1

Monitoring Response to Treatment

Reassess at 48-72 hours for clinical improvement: 1

• Resolution of fever
• Decreased respiratory symptoms
• Improved oxygen saturation
• Ability to tolerate oral intake

If no improvement by 5 days, evaluate for: 1

• Resistant pathogen requiring different antibiotic
• Complications (empyema, lung abscess)
• Alternative diagnosis
• Non-infectious inflammatory process