Treatment of Chlamydia Pneumonia
For adults with Chlamydia pneumonia, the recommended treatment is doxycycline 100 mg orally twice daily for 7 days, or a macrolide such as azithromycin 500 mg on day 1 followed by 250 mg daily for 4 days, or clarithromycin 500 mg twice daily for 7-14 days. 1
Treatment Options by Patient Population
Adults
- First-line options:
- Alternative options:
Children
- Children who weigh <45 kg:
- Erythromycin base or ethylsuccinate 50 mg/kg/day orally divided into 4 doses daily for 14 days 1
- Children who weigh >45 kg but are <8 years old:
- Azithromycin 1 g orally in a single dose 1
- Children ≥8 years old:
- Azithromycin 1 g orally in a single dose, OR
- Doxycycline 100 mg orally twice daily for 7 days 1
Infants with C. trachomatis pneumonia
- Erythromycin base or ethylsuccinate 50 mg/kg/day orally divided into 4 doses daily for 14 days 1
- Follow-up is recommended as treatment effectiveness is approximately 80% and a second course may be required 1
Clinical Considerations
Diagnostic Approach
- Diagnosis of Chlamydia pneumonia can be challenging as clinical presentation may mimic other atypical pneumonias 5, 6
- Common symptoms include:
- Gradual onset of symptoms
- Persistent cough (often non-productive)
- Low-grade fever
- In infants: staccato cough with tachypnea 1
- Laboratory findings may include peripheral eosinophilia in infants 1
Treatment Duration
- Treatment duration should generally not exceed 8 days in responding patients 1
- For C. pneumoniae specifically, 7-14 days of therapy is typically recommended 1
- For infants with C. trachomatis pneumonia, 14 days of therapy is recommended 1
Special Considerations
- For patients with comorbidities (chronic heart, lung, liver, or renal disease; diabetes; alcoholism; malignancies; immunosuppression), consider respiratory fluoroquinolones or a β-lactam plus a macrolide 1
- Azithromycin has FDA approval for community-acquired pneumonia due to Chlamydia pneumoniae in patients appropriate for oral therapy 7
- Levofloxacin is indicated for community-acquired pneumonia due to Chlamydophila pneumoniae 4
Follow-up Recommendations
- Follow-up is particularly important for infants with chlamydial pneumonia to ensure resolution 1
- Some infants with chlamydial pneumonia may have abnormal pulmonary function tests later in childhood 1
- Sexual abstinence for 7 days after completing treatment is recommended for sexually transmitted C. trachomatis infections 8
Common Pitfalls and Caveats
- Erythromycin has approximately 80% effectiveness in treating chlamydial pneumonia; a second course may be required if symptoms persist 1
- Azithromycin should not be used in patients with known QT interval prolongation, history of torsades de pointes, or uncompensated heart failure due to risk of cardiac arrhythmias 7
- Fluoroquinolones should be used cautiously in patients with risk factors for QT prolongation 4
- Doxycycline should be avoided in pregnant women and children under 8 years of age due to risk of dental staining 1
- Macrolides are preferred for pregnant women with chlamydial infections 3