Community Acquired Pneumonia (CAP)
Diagnosis
Requires the presence of clinical features (cough, fever, sputum production, pleuritic chest pain) AND chest infiltrate demonstrated on imaging
Common Causative Organisms
Streptococcus pneumoniae, Mycoplasma pneumoniae, Chlamydia pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, Respiratory viruses
Outpatient Empiric CAP Treatment
Previously healthy AND no antibiotics in the past 3 months |
Doxycycline 100 mg PO BID (preferred) OR Amoxicillin 1 gm PO TID (alternative) |
Antibiotic use in prior 3 months OR Presence of co-morbidities
|
Combination Therapy (preferred): Doxycycline 100 mg PO BID PLUS Amoxicillin 1 gm PO TID OR Cefpodoxime 200 mg PO BID
Monotherapy (alternative) Levofloxacin* 750 mg PO daily |
* Contact ASP PharmD (preferred) or ID fellow for approval unless patient has severe penicillin allergy
Suggested Duration of Therapy
- Patients should be treated for a minimum of 5 days
- Most patients are treated for 5-7 days
Clinical Pearls
- Routine sputum cultures and urine antigen tests are not recommended
- Consider testing for influenza and COVID-19 if patient exhibits flu-like symptoms during periods of high flu and SARS-CoV-2 activity
- Signs and symptoms of CAP may be lacking or altered in elderly patients
- Cough and chest X-ray abnormalities may take up to 6 weeks to improve and are NOT a valid reason to extend antibiotic courses
Inpatient Empiric CAP Treatment
Suggested Duration of Therapy
- Patients should be treated for a minimum of 5 days unless the patient has confirmed MRSA or Pseudomonas aeruginosa infection in which case the minimum duration is 7 days
- Azithromycin 500 mg PO/IV q24h x 3 doses is sufficient for atypicals; if legionella is suspected treat for 7 days
- Patient should be afebrile for 48-72h, and should have no more than 1 of the following before stopping antibiotics:
- Heart rate > 100 beats/min
- Respiratory rate > 24 breaths/min
- Systolic blood pressure < 90 mmHg
- Arterial O2 saturation < 90%
- Altered mental status
Clinical Pearls
- Sputum cultures should be obtained for hospitalized patients with severe CAP or when strong risk factors for MRSA or Pseudomonas are identified
- MRSA nares should be obtained if empiric vancomycin therapy is initiated for pneumonia to assist with de-escalation (strong negative predictive value)
- For suspected influenza, obtain nasopharyngeal swabs for influenza antigen testing and respiratory virus DFA; if patient is hospitalized, place on droplet precautions until tests are negative, and treat with oseltamivir 75 mg PO bid for 5 days (reduce dose in renal insufficiency). ICU patients, immunocompromised patients, and obese patients may require higher doses and/or prolonged therapy.
References:
Metlay, Joshua P., et al. "Diagnosis and treatment of adults with community-acquired pneumonia. An official clinical practice guideline of the American Thoracic Society and Infectious Diseases Society of America." American journal of respiratory and critical care medicine 200.7 (2019): e45-e67.