Community Acquired Pneumonia (CAP) (Antimicrobial)

BTS 2009
BTS annotated Update 2015
NICE guideline (CG191) Pneumonia in adults: diagnosis and management 

Additional information for frail elderly patients is available

Antibiotic therapy in CAP is not dependent on CRP level
START ANTIBIOTICS IMMEDIATELY ONCE THE DIAGNOSIS HAS BEEN MADE

Assess severity using CURB65 score and markers of sepsis.  Clinicians without access to a recent blood urea level should use CRB65 score.

CURB65 score is defined by 1 point being scored for each of the following:

Confusion (mental test score 8 or less, new disorientation in person, time or place);
Urea >7mmol/L;
Respiratory rate ≥30/min;
Blood pressure (SBP <90mmHg, diastolic ≤60mmHg);
Age ≥65 years.

For CAP with features of SEPSIS, treat as severe ie CRB65 score 3 to 4 or CURB65 score 3 to 5

The CURB65 or CRB65 should be recorded in the patient’s medical notes.

The CURB65 or CRB65 should be recorded in the patient’s medical notes.
CURB65 or CRB65 score identifies those patients that may safely be treated out of hospital. Social support and treatment compliance issues should be considered in addition to CURB/CRB65 score. The use of CURB65 can over-estimate the severity of illness in the frail patient. It is not appropriate to use CURB65 score to assess severity in a post-operative patient as these parameters may already be raised in the immediate post-operative period. There are a number of significant drug interactions with clarithromycin and levofloxacin, eg warfarin, theophylline; see the BNF for a comprehensive list. Both clarithromycin and levofloxacin can prolong the QT interval so use with caution in patients with an existing prolonged QT interval or on other drugs known to have this effect. See BNF for more detailed information. Clarithromycin is contra-indicated in patients taking simvastatin. If treatment with clarithromycin is necessary simvastatin should be temporarily discontinued and, if necessary, replaced with atorvastatin, up to a maximum of 20mg daily, for the duration of clarithromycin therapy. In addition to a number of other severe side effects, levofloxacin can lower the seizure threshold and can cause tendon damage (including rupture) occurring within 48 hours of starting treatment or several months after stopping; avoid if there is a history of quinolone-associated tendon damage. The risk of tendon damage increases in patients over 60 years of age and in those taking concomitant steroids.  See updated MHRA warnings on fluoroquinolone use published January 2024.

Duration Note

Stop antibiotic treatment after 5 days unless microbiological results suggest a longer course is needed or the person is not clinically stable, for example, if they have had a fever in the past 48 hours or have more than 1 sign of clinical instability (systolic blood pressure less than 90 mmHg, heart rate more than 100/minute, respiratory rate more than 24/minute, arterial oxygen saturation less than 90% or partial pressure of oxygen of more than 60 mmHg in room air).

Consider early intravenous to oral switch with clinical improvement. Duration of therapy includes intravenous and oral treatment.

Remember the risk of tuberculosis, particularly in immunocompromised patients and in travellers or recent settlers from abroad.

For glossary of terms see Glossary.