CAP, Outpatient

[Am J Respir Crit Care Med 2019;200: e45-67, NICE guideline]
 

- Calculation of CRB-65, CURB-65 score, or Pneumonia Severity Index (PSI) is recommended to help determine severity, site of care, and mortality risk.

 

Mild - based on clinical judgement and guided by CRB-65 score 0 or CURB-65 0 or 1 or PSI score I or II.
 
Usual Pathogens

S. pneumoniae
Mycoplasma pneumoniae
Chlamydophila pneumoniae

 

Therapy Dose Duration
Amoxicillin 1g PO tid

3 days

Penicillin/amoxicillin allergy    
Doxycycline 200mg PO once, then 100mg PO bid

3 days

Alternative

Therapy Dose Duration
Azithromycin 500mg PO daily 3 days
or    
Clarithromycin 500mg PO bid

3 days

  XL 1g PO daily  

 

 

 

Moderate - based on clinical judgement and guided by CRB-65 score 1 or 2 or CURB-65 2 or PSI score III

 

Usual Pathogens

S. pneumoniae
H. influenzae
S. aureus
Moraxella catarrhalis
Enterobacterales
Mycoplasma pneumoniae
Legionella spp
Chlamydophila pneumoniae
 

Consider SARS-CoV-2, and influenza during epidemic season.

 
Therapy Dose Duration
Amoxicillin 1g PO tid

3 days

or    
Amoxicillin-clavulanate 875mg PO bid

3 days

If CRB-65 score 1 and significant co-morbidity, or CRB-65 score 2, add:    
[Doxycycline 200mg PO once, then

3 days

  100mg PO bid  
or    
Azithromycin 500mg PO daily 3 days
or    
Clarithromycin] 500mg PO bid

3 days

  XL 1g PO daily  
Penicillin/amoxicillin allergy    
Cefuroxime axetil 500mg PO bid 3 days
If CRB-65 score 1 and significant co-morbidity, or CRB-65 score 2, add:    
[Doxycycline 200mg PO once, then 3 days
or 100mg PO bid  
Azithromycin 500mg PO daily

3 days

or    
Clarithromycin]  500mg PO bid 3 days
Penicillin/amoxicillin & cefuroxime allergy    
Levofloxacin 750mg PO daily 3 days

 

- Expect clinical improvement/stability at 48-72 hours of appropriate therapy. If no improvement, or deterioration, consider non-infectious etiologies as well as the following infectious etiologies (depending on epidemiologic setting/risk factors):

 

  • Methicillin-resistant S. aureus (MRSA)
  • Viral pneumonia, including Influenza, SARS-CoV-2
  • Mycobacterium tuberculosis
  • Nocardia spp
  • Actinomyces spp
  • Chlamydophila psittaci
  • Coxiella burnetti (Q fever)
  • Francisella tularensis (tularemia)
  • Bordetella pertussis (whooping cough)
  • Endemic fungi (Histoplasma capsulatum, Coccidioides immitis, Cryptococcus neoformans, Blastomyces spp)
  • Pneumocystis jirovecii