Brain abscess medical therapy
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Sheng Shi, M.D. [2]
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Overview
Treatment of brain abscess requires a multidisciplinary approach to lower intracranial pressure, delineate extent of infection, evacuate purulent materials, administer appropriate antibiotics, and obtain tissue specimens.
Treatment
Initial treatment includes lowering the intracranial pressure and administering empiric antibiotics. Stereotactic needle biopsy can be performed to obtain tissues for cultures.
A brain abscess greater than 3 cm in diameter should be considered for surgical drainage if accessible, with an exception of tuberculous brain abscess which is treated with anti-tuberculous agents.
- Antibiotics: Brain abscesses are usually polymicrobial, with the most common bugs being microaerophilic streptococci (viridans) and anaerobic bacteria (bacteroides, anaerobic strep and fusobacterium).
- S. aureus, and enterobacteriacae are also seen.
- Bugs associated with trauma include S. aureus and clostridium sp.
- Empiric Rx usually starts with high-dose PCN (10 – 20 million units / d), metronidazole, +/- a 3rd gen cephalosporin.
- Even if the abscess is associated with a dental procedure and other organisms are considered (actinomyces sp.) they generally respond to the above Rx.
- If extending from an otitis, empiric Rx should also cover pseudomonas and enterobacteriacaea.
- If hematogenously spread, coverage depends on the original bug.
- The penetration of abx into an abscess does not necessarily equate with their penetration into the CSF (the blood-brain barrier is not the same as the blood-CSF barrier).
- Drugs like vancomycin, which have poor CSF levels (<10% of serum) have been shown to have good abscess levels (90% of serum).
- Most patients are treated parenterally for at least 8w.
- Some authors also recommend an additional 2 – 3 month course of oral abx to clear up any ‘residual’ infection and to prevent relapses.
- One study actually suggests that, when combined with surgical excision, 3w may be adequate.
- Other studies have reported good outcomes with abx alone in patients with small lesions (<2cm), in well vascularized areas (cortex), who were poor surgical candidates.
- There have not been any studies reporting benefit from intra-thecal or intra-abscess abx.
- There seems to be consensus on obtaining q 2 – 4w f/u CT/MRI scans to document resolution.
Adjuvants
- Although steroids have not been studies in well-designed trials, many authors use them in patients with elevated ICP.
- Some animal studies suggest interference with granulation tissue formation and bacterial clearance.
- Anticonvulsants are recommended prophylactically for the 1st 3m, though the data supporting this is lacking.[1]
Antimicrobial Regimen – Empiric Therapy
Brain Abscess in Otherwise Healthy Patients
- Cefotaxime 8–12 g/day q4–6h OR Ceftriaxone 4 g/day q12h AND
- Metronidazole 30 mg/kg/day q6h
- Meropenem 6 g/day q8h
Brain Abscess with Comorbidities
- Cefotaxime 8–12 g/day q4–6h OR Ceftriaxone 4 g/day q12h AND
- Metronidazole 30 mg/kg/day q6h
- Penicillin G 24 MU q4h AND
- Metronidazole 30 mg/kg/day q6h
- Cefotaxime 8–12 g/day q4–6h OR Ceftriaxone 4 g/day q12h AND
- Vancomycin 30–45 mg/kg/day q8–12h
- Penicillin G 24 MU q4h AND
- Metronidazole 30 mg/kg/day q6h AND
- TMP-SMZ 10–20 mg/kg/day q6–12h
- Vancomycin 30–45 mg/kg/day q8–12h AND
- Gentamicin 5 mg/kg/day IV q8h
- Cefotaxime 8–12 g/day q4–6h OR Ceftriaxone 4 g/day q12h
- Cefotaxime 8–12 g/day q4–6h OR Ceftriaxone 4 g/day q12h AND
- Metronidazole 30 mg/kg/day q6h AND
- Voriconazole 8 mg/kg/day q12h AND
- TMP-SMZ 10–20 mg/kg/day q6–12h OR Sulfadiazine 4–6 g/day q6h
- Cefotaxime 8–12 g/day q4–6h OR Ceftriaxone 4 g/day q12h AND
- Sulfadiazine 4–6 g/day q6h AND
- Pyrimethamine 25–100 mg/day qd
- Vancomycin 30–45 mg/kg/day q8–12h
- Isoniazid 300 mg qd AND
- Rifampin 600 mg qd AND
- Pyrazinamide 15–30 mg qd AND
- Ethambutol 15 mg/kg/day qd
Antimicrobial Regimen – Pathogen-Based Therapy
Bacteria
- Penicillin G 24 MU q4h
- Metronidazole 30 mg/kg/day q6h
- Cefotaxime 8–12 g/day q4–6h OR Ceftriaxone 4 g/day q12h
- Metronidazole 30 mg/kg/day q6h
- Cefotaxime 8–12 g/day q4–6h OR Ceftriaxone 4 g/day q12h
- Ampicillin 12 g/day q4h OR Penicillin G 24 MU q4h
- TMP-SMZ 10–20 mg/kg/day q6–12h OR Sulfadiazine 4–6 g/day q6h
- Metronidazole 30 mg/kg/day q6h
- Ceftazidime 6 g/day q8h OR Cefepime 6 g/day q8h
- Vancomycin 30–45 mg/kg/day q8–12h
- Penicillin G 24 MU q4h
Fungi
- Voriconazole 8 mg/kg/day q12h
- Amphotericin B lipid complex 5 mg/kd/day q24h OR Amphotericin B deoxycholate 15 mg/kg/day q8h
- Amphotericin B lipid complex 5 mg/kd/day q24h OR Amphotericin B deoxycholate 15 mg/kg/day q8h
- Amphotericin B lipid complex 5 mg/kd/day q24h OR Amphotericin B deoxycholate 15 mg/kg/day q8h
- Voriconazole 8 mg/kg/day q12h
Protozoa
- Sulfadiazine 4–6 g/day q6h AND
- Pyrimethamine 25–100 mg/day qd
References
- ↑ Mandell, Gerald L.; Bennett, John E. (John Eugene); Dolin, Raphael. (2010). Mandell, Douglas, and Bennett's principles and practice of infectious disease. Philadelphia, PA: Churchill Livingstone/Elsevier. ISBN 0-443-06839-9.