Community Acquired Pneumonia (CAP) (Antimicrobial)

Warning

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.

Drug details

CAP with history of recent foreign travel (discuss with Microbiology/ID consultant, including options for penicillin allergy)

Oral/IV clarithromycin 500mg twice daily PLUS oral/IV amoxicillin 1g three times daily

5 days – see duration note above.

CAP Mild (CRB65 = 0, CURB65 = 0 to 1)

Mild to moderate: home or hospital-treated

Oral amoxicillin 1g 3 times daily OR oral doxycycline 200mg stat then 100mg once daily

5 days – see duration note above.

If no response in 48 hours, ADD doxycycline to amoxicillin for atypical cover and consider admission.

CAP Moderate (CRB65 = 1 to 2, CURB65 = 2)

Moderate: home or hospital-treated

Oral/IV amoxicillin 1g 3 times daily PLUS oral doxycycline 100mg twice daily

5 days – see duration note above.

CAP Moderate (CRB65 = 1 to 2, CURB65 = 2)

Moderate: home or hospital-treated, penicillin allergy or patient with recent course of amoxicillin PLUS doxycycline

Oral levofloxacin (rarely need for intravenous therapy due to excellent bioavailability) 500mg twice daily (see BNF warnings and MHRA Drug Safety Alert (updated 22 January 2024))

5 days – see duration note above.

CAP Severe (CRB65 = 3 to 4, CURB65 = 3 to 5 OR 0 to 2 with features of sepsis)

If no prior antibiotic treatment in the community

IV amoxicillin 1g 3 times daily PLUS oral doxycycline 100mg twice daily

5 days – see duration note above.

CAP Severe (CRB65 = 3 to 4, CURB65 = 3 to 5 OR 0 to 2 with features of sepsis)

If antibiotics given in the community before admission, in penicillin allergy or proven or suspected Legionella infection

Oral levofloxacin (rarely need for intravenous therapy due to excellent bioavailability) 500mg twice daily (see BNF warnings and MHRA Drug Safety Alert (updated 22 January 2024))

5 days – see duration note above.

CAP Severe (CRB65 = 3 to 4, CURB65 = 3 to 5 OR 0 to 2 with features of sepsis)

In penicillin allergy AND levofloxacin not suitable:

Contact Microbiology/ID consultant

Editorial Information

Last reviewed: 25/06/2024

Next review date: 25/06/2027

Author(s): Antimicrobial Management Team.

Version: 4

Approved By: NHS Highland Antimicrobial Management Team

Reviewer name(s): Alison Macdonald, Area Antimicrobial Pharmacist.

Document Id: AMT158