Adult

Community-acquired pneumonia (CAP): moderate/ severe (CURB65=2-5)

If sepsis is suspected see Systemic sepsis of UNKNOWN source

Community-acquired pneumonia (CAP)

  • Symptoms consistent with lower respiratory tract infection (i.e. fever, cough, chest pain) AND evidence of consolidation on Chest X-ray.
  • For acutely deteriorating patients consider referral to ITU, urgent chest imaging (ultrasound, CT) if clinically appropriate.

CURB65: Confusion (AMT 8 or less), Urea greater than 7mmol/L, Resp rate 30 breaths per minute or more, BP less than 90mmHg systolic or 60mmHg or less diastolic, Age 65 years or older

  • Take blood cultures and appropriate samples (e.g. pus, pleural fluid) for culture
  • Consider further investigation for atypical pneumonia including urine for Legionella antigen  
  • When community respiratory viruses are common, SarsCoV2, RSV and/or influenza testing is indicated
  • HIV AgAb testing is indicated
  • Antibiotics should be given within 4 hours
  • See also NICE's guideline on pneumonia in adults: diagnosis and management (NG250).

Treat for 3-5 days (review iv daily)

Review empirical treatment within 48 hours 

Preferred

amoxicillin 1g iv tds or 500mg po tds (oral dose can be increased to 1g po tds in particularly severe cases where the patient is able to tolerate that dose) 

AND  doxycycline 100mg po bd

Alternative

For non-severe and severe penicillin allergy: clarithromycin 500mg po bd (iv if NBM)

Alternative in pregnancy for patients with penicillin allergy: erythromycin 500 mg po qds (iv if NBM)

For patients with penicillin allergy label consider penicillin allergy assessment and delabelling

Additional information

  • High severity patients slow to settle, either clinically or biomarkers (when following biomarkers), suggest reinvestigation and referral to Micro/ID and/or Respiratory Medicine.
  • If patient has CURB65 score of 2 consider referral to Hospital at Home service.
  • Lung ultrasound can be used in the diagnosis of pneumonia in hospital, for example:
    • for rapid point-of-care diagnosis in a sick or deteriorating person
    • where there is a possible alternative diagnosis, for example, heart failure
    • for investigating associated complications such as pleural disease.
  • Explain to patient that after starting treatment their symptoms should steadily improve, although the rate of improvement will vary with the severity of the pneumonia. Most adults can expect that by:
    • 1 week: fever should have resolved
    • 4 weeks: chest pain and sputum production should have substantially reduced
    • 6 weeks: cough and breathlessness should have substantially reduced 
    • 3 months: most symptoms should have resolved but fatigue may still be present 
    • 6 months: they will feel back to normal
  • Give advice to people with community-acquired pneumonia (or their parents or carers, if appropriate) about:
    • possible adverse effects of the antibiotic(s) 
    • seeking further advice (if the person is receiving treatment in the community or via hospital at home service) if:
      •     symptoms worsen rapidly or significantly or
      •     symptoms do not start to improve within 3 days or
      •     the person becomes systemically unwell.

Editorial Information

Last reviewed: 31 Dec 2025

Author(s): AMST.

Approved By: ASG