38-year-old man with a history of alcohol abuse presents to you with symptoms of sinusitis

metronidazole and ceftriaxone

Educational Objective:

Treat brain abscess.

Key Point:

Select empiric antibiotics for a patient with brain abscess based upon presumptive source of infection. Surgical drainage is often required.

Explanation:

The patient has a brain abscess originating from a focus of sinusitis. Common organisms involved in this condition include species of Streptococcus, Haemophilus, and anaerobes. The best antibiotic coverage in this case will include ceftriaxone and metronidazole. Aspiration of the abscess and surgical evaluation are also a consideration. Corticosteroids could be used in the presence of mass effect.

The choice of antibiotics for a brain abscess depends on the subjacent conditions. For infections with presumptive initial foci in the mouth, ear, or sinuses, combination ceftriaxone/metronidazole is reasonable. If a hematogenous source is likely (eg, endocarditis), or occurs in the presence of penetrating trauma, then vancomycin should be added to cover for methicillin-resistant Staphylococcus aureus. Postneurosurgical cases may benefit from coverage for methicillin-resistant Staphylococcus aureus and for Pseudomonas.

Certain antibiotics, such as aminoglycoside, do not penetrate well into the central nervous system and are not recommended.

References:

Arlotti M, Grossi P, Pea F, Tomei G, Vullo V, et al; GISIG Working Group on Brain Abscesses. Consensus document on controversial issues for the treatment of infections of the central nervous system: bacterial brain abscesses. Int J Infect Dis. 2010;14(suppl 4):S79-S92.

Helweg-Larsen J, Astradsson A, Richhall H, Erdal J, Laursen A, Brennum J. Pyogenic brain abscess, a 15 year survey. BMC Infect Dis. 2012;12:332.

Gaillard, Frank. “Brain Abscess.” Radiopaedia.org.