How should I treat an otherwise healthy adult outpatient with a cough due to community-acquired pneumonia?

Treatment of Cough Due to Community-Acquired Pneumonia in Healthy Adult Outpatients

For an otherwise healthy adult outpatient with cough due to community-acquired pneumonia, treat empirically with oral antibiotics covering Streptococcus pneumoniae and atypical pathogens for a minimum of 5 days, ensuring the patient is afebrile for 48-72 hours before stopping therapy. 1

Antibiotic Selection

First-Line Options for Healthy Outpatients

• Amoxicillin is the first-choice antibiotic for outpatient management when no risk factors for resistant organisms are present 1
• Macrolides (azithromycin or clarithromycin) are appropriate alternatives, particularly effective against atypical pathogens like Mycoplasma pneumoniae 1, 2
• Respiratory fluoroquinolones (levofloxacin 750 mg daily or moxifloxacin) are highly effective alternatives with >90% clinical success rates and provide coverage for both typical and atypical pathogens 2, 3

Specific Dosing Recommendations

• Levofloxacin 750 mg orally once daily for 5 days is an evidence-based short-course regimen with equivalent efficacy to longer courses 4
• Azithromycin 500 mg daily for 3 days represents an effective short-course macrolide option 5
• Amoxicillin-clavulanate should be used if beta-lactamase-producing Haemophilus influenzae is common in your area or if the patient has chronic lung disease 1

Treatment Duration

• Minimum 5 days of antibiotic therapy is required for all patients with community-acquired pneumonia 1
• Patient must be afebrile for 48-72 hours and have no more than one sign of clinical instability before discontinuing antibiotics 1
• Usual practice is 5-7 days for uncomplicated cases managed at home 1
• Inform patients that cough may persist beyond the antibiotic course and does not necessarily indicate treatment failure 1

Clinical Assessment Before Treatment

Symptoms and Signs Suggesting Pneumonia

• Presence of cough, dyspnea, pleural pain, sweating/fevers/shivers, temperature ≥38°C, tachypnea, and new localizing chest examination signs strongly suggest pneumonia 1
• Absence of runny nose combined with breathlessness, crackles, diminished breath sounds, tachycardia, and fever ≥38°C increases likelihood of pneumonia 1

Role of C-Reactive Protein

• CRP ≥30 mg/L in addition to suggestive symptoms and signs increases the likelihood of pneumonia and strengthens the indication for antibiotics 1
• CRP <10 mg/L or 10-50 mg/L without dyspnea and daily fever makes pneumonia less likely 1
• Measuring CRP is suggested to strengthen both diagnosis and exclusion of pneumonia 1

Chest Radiography Indications

• Order chest radiography when vital signs are abnormal (fever, tachypnea, tachycardia, hypotension) to improve diagnostic accuracy 1
• Do not routinely use antibiotics when vital signs and lung exams are normal, even with isolated auscultatory findings 1, 6

Microbiological Testing

• Routine microbiological testing is not needed for outpatients with suspected pneumonia 1
• Sputum culture and blood cultures are not recommended for patients without risk factors for severity or unusual organisms 1

Monitoring and Follow-Up

Expected Clinical Response

• Fever should resolve within 48 hours of starting appropriate antibiotic therapy 1
• Patients should return if fever does not resolve within 48 hours, as this may indicate treatment failure 1
• Assess clinical response at 48-72 hours after initiating therapy 5

When to Reassess or Change Therapy

• Do not change antibiotics within the first 72 hours unless the patient's clinical state worsens 5
• If no improvement by 48-72 hours, consider investigation for treatment failure including resistant organisms, complications (empyema, abscess), or alternative diagnoses 1

Critical Pitfalls to Avoid

• Do not prescribe antibiotics for acute cough without clinical or radiographic evidence of pneumonia when vital signs and lung exams are normal 1, 7
• Remember that many respiratory infections are viral; only treat when bacterial infection is clinically suspected based on fever, purulent sputum, and systemic signs 1, 5
• Antibiotic therapy must always be active against Streptococcus pneumoniae, which is the most frequently encountered pathogen in community-acquired pneumonia 1
• Patients with comorbidities or recent antibiotic use require broader coverage and should not receive simple aminopenicillin monotherapy 2, 8

Special Considerations for Influenza

• Test for influenza when it is circulating in the community, as this may affect treatment decisions 3
• Initiate antiviral treatment within 48 hours of symptom onset if influenza is suspected, which may decrease antibiotic usage and hospitalization 1