Adult

Community-acquired Brain Abscess

  • Urgent Micro/ID consult
  • Urgent biopsy and drainage with collection of specimens for culture is considered optimal management to ensure source control of brain abscess. 
  • Modify treatment according to sensitivity test results. 
  • HIV testing is indicated

If post neurosurgical infection see Meningitis: post-neurosurgical infection

Treat for 4-6 weeks (initial 2-4 weeks IV then PO conversion). Once source control is achieved with aspiration or surgical drainage oral conversion can be considered.   

Some difficult to treat cases might require longer treatment. Always discuss with Micro/ID.

Preferred empiric treatment

Includes penicillin allergy (non-severe)  

ceftriaxone 2g iv bd

AND

metronidazole 400mg po tds (or 500mg iv tds)

For MRSA positive patients: ADD linezolid 600mg po bd (iv if NBM) (See linezolid drug monograph for information about monitoring required)

If unable to have linezolid: substitute linezolid with vancomycin  iv

 

Once culture and sensitivity available see section below.

 

See below for oral follow on

Alternative empiric treatment

For penicillin allergy (severe)

moxifloxacin* 400mg po od (iv if NBM)

Moxifloxacin may induce convulsions in patients with or without a history of convulsions – use with caution

For MRSA positive patients: ADD linezolid 600mg po bd (iv if NBM) (See linezolid drug monograph for information about monitoring required)

If unable to have linezolid: substitute linezolid with vancomycin  iv

 

*Ensure that the patient is given the Fluoroquinolone MHRA patient information leaflet. Fluoroquinolones, including moxifloxacin, are associated with disabling and potentially long-lasting or irreversible side effects. See Fluoroquinolone antibiotics - severe adverse effects

 

See below for oral follow on

Once culture and sensitivity available

Discuss with Micro/ID.

If cultures show penicillin susceptible streptococcus spp and there is no penicillin allergy then step down to: 

amoxicillin 1g iv tds OR benzylpenicillin 2.4g iv 4-6 hourly

 

See below for oral follow on

Oral follow-on

Always discuss oral options with Micro ID; selection will be determined by culture results and susceptibilities, as well as history of penicillin allergy. Options include:

amoxicillin 1g po tds 

OR

co-trimoxazole 960mg po bd 

OR

linezolid 600mg po bd (See linezolid drug monograph for information about monitoring required)

OR

chloramphenicol 12.5mg/kg po qds (maximum 4g in 24 hours round to nearest 250mg capsule). Use adjusted body weight to calculate dose if actual body weight is greater than 20% of ideal body weight. 

OR

moxifloxacin* 400mg po od. (Moxifloxacin may induce convulsions in patients with or without a history of convulsions – use with caution)

*Ensure that the patient is given the Fluoroquinolone MHRA patient information leaflet. Fluoroquinolones, including moxifloxacin, are associated with disabling and potentially long-lasting or irreversible side effects. See Fluoroquinolone antibiotics - severe adverse effects

Editorial Information

Last reviewed: 01 Jun 2025

Author(s): AMST.

Approved By: MMTC