Aspiration Pneumonia


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

If penicillin allergy:

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

14 days

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.

Last reviewed: 25 August 2022

Next review: 25 August 2025

Author(s): Antimicrobial Management Team

Version: 2

Approved By: TAM Subgroup of ADTC

Reviewer Name(s): Area Antimicrobial Pharmacist

Document Id: AMT156