Duration

Patients with CAP should be treated a minimum of 5 days and can have antibiotics discontinued when:

T≤ 37.8°C for 48 hours
AND
Have no more than 1 CAP-associated sign of clinical instability:

sBP < 90 mmHg
HR > 100/min
RR > 24/min
Sat <90% or PaO2 <60 mmHg in room air

Treatment Pearls

Repeating CXR

Cough and chest x-ray abnormalities may take several weeks to resolve. If the patient is otherwise improving and afebrile, extension of antibiotic course is NOT necessary.

Repeated chest x-rays to document resolution of opacities should not be performed sooner than 6 weeks, unless patient’s condition is worsening
Repeat chest x-rays are warranted if concerned about underlying malignancy (higher risk in smokers and those over 50 years old)

S. pneumoniae bacteremia

Uncomplicated CAP with S. pneumoniae bacteremia includes patients who become afebrile within 72 hours, and have no evidence of necrotizing pneumonia, lung abscess, empyema, or extra-pulmonary disease. The presence of bacteremia alone does NOT require a prolonged course of parenteral antibiotics. Treat as per usual CAP duration above

S. aureus and Legionella

Pneumonia due to S. aureus or Legionella are exceptions and may require 14 days of antibiotics. Infectious Diseases consultation recommended.

Pneumonia with complications

Necrotizing pneumonia, lung abscess, or empyema will require prolonged therapy. Respirology and/or Infectious Diseases consultation recommended

Azithromycin Dosing Notes

Azithromycin 500 mg daily x 3 days

OR

Azithromycin 500 mg once, then 250 mg daily x 4 days

Azithromycin has a long tissue half-life which allows short treatment durations.