Aspiration Pneumonia (Antimicrobial)

Warning

ASPIRATION PNEUMONITIS DOES NOT REQUIRE ANTIMICROBIAL THERAPY

Consider aspiration pneumonia if:

  • history of impaired swallowing
  • vomiting with possible aspiration 48 hours before.

Infection is indicated by change in sputum quality to purulent or mucopurulent or fever and new chest x-ray changes.

For glossary of terms see Glossary.

Drug details

Mild to moderate (IV route only if nil by mouth)

Oral metronidazole 400mg three times daily
OR IV metronidazole 500mg three times daily PLUS Oral/IV amoxicillin 1g three times daily

7 days

Mild to moderate if penicillin allergy

Oral metronidazole 400mg three times daily
OR IV metronidazole 500mg three times daily PLUS Oral/IV clarithromycin 500mg twice daily

7 days

Severe aspiration pneumonia

IV metronidazole 500mg three times daily PLUS IV gentamicin - refer to NHS Highland gentamicin guidelines. Stop after three days if no evidence of gram negative infection PLUS IV amoxicillin 1g three times daily.

14 days

Severe if penicillin allergy

Oral/IV levofloxacin 500mg twice daily (see BNF warnings and MHRA Drug Safety Alert (updated 22 January 2024)PLUS IV metronidazole 500mg three times daily

14 days

Severe if MRSA likely or over 65 yrs

ADD IV vancomycin - refer to NHS Highland vancomycin guidelines

14 days.
Change of pathogens compared to community-acquired infection.  Pseudomonas sp, gram negative bacilli and MRSA are possibilities.  Seek advice.  Assess severity using SIRS criteria.

Editorial Information

Last reviewed: 25/08/2022

Next review date: 25/08/2025

Author(s): Antimicrobial Management Team.

Version: 2.1

Approved By: TAM Subgroup of ADTC

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

Document Id: AMT156