Listeria monocytogenes meningoencephalitis
For meningoencephalitis caused by Listeria monocytogenes, benzylpenicillin is the preferred drug. In adults and children, use:
benzylpenicillin 2.4 g (child: 60 mg/kg up to 2.4 g) intravenously, 4-hourly. For dosage adjustment in adults with kidney impairment, see benzylpenicillin dosage adjustment. See below for duration of therapy and intravenous to oral switch. benzylpenicillin benzylpenicillin benzylpenicillin
Listeriosis is a notifiable disease and may be associated with contamination of food. Discuss all confirmed cases with the local public health authority12.
For patients who report penicillin hypersensitivity, verify their allergy. In some patients it may be appropriate to directly delabel their allergy by taking an extensive allergy history (see Clinical history for initial assessment of patients reporting penicillin hypersensitivity). In patients whose penicillin allergy has been delabeled, benzylpenicillin should be used.
Seek expert advice for patients with a verified allergy. For patients who have had a nonsevere (immediate or delayed) or a severe immediate3 hypersensitivity reaction to a penicillin, options that an infectious diseases physician or clinical microbiologist may use include:
- performing desensitisation
- using trimethoprim+sulfamethoxazole (see dosage below).
For patients who have had a severe delayed4 hypersensitivity reaction to a penicillin, use:
trimethoprim+sulfamethoxazole (adult and child 1 month or older) 5+25 mg/kg up to 480+2400 mg intravenously, 8-hourly. For dosage adjustment in adults with kidney impairment, see trimethoprim+sulfamethoxazole dosage adjustment. See below for duration of therapy and intravenous to oral switch. trimethoprim + sulfamethoxazole trimethoprim+sulfamethoxazole trimethoprim+sulfamethoxazole
There is limited evidence that combination therapy with a beta lactam plus trimethoprim+sulfamethoxazole improves outcomes. Addition of an aminoglycoside to the regimen is not beneficial.
Duration of therapy and intravenous to oral switch: the usual duration is 3 weeks, extended to 6 weeks in patients with immune compromise. For treatment extending beyond 3 weeks, oral therapy with trimethoprim+sulfamethoxazole can be used to complete the course if clinical features of infection have resolved with intravenous therapy, and the patient is able to tolerate oral medication. Use:
trimethoprim+sulfamethoxazole (adult and child 1 month or older) 5+25 mg/kg up to 480+2400 mg orally or enterally, 8-hourly. For dosage adjustment in adults with kidney impairment, see trimethoprim+sulfamethoxazole dosage adjustment. For adults, see Calculated dose and number of tablets of trimethoprim+sulfamethoxazole to achieve a 5+25 mg/kg dose in adults for calculated weight-banded doses in number of double-strength tablets.
The benefit of dexamethasone in Listeria monocytogenes meningoencephalitis is unclearCharlier 2017 but several observational studies suggest benefitAmaya-Villar 2010Brouwer 2023Moscatt 2022Pelegrin 2014. If dexamethasone is used, add:
dexamethasone 10 mg (child: 0.15 mg/kg up to 10 mg) intravenously, preferably starting before the first dose of antibiotic, then 6-hourly for 4 days (empirical + directed therapy). dexamethasone dexamethasone dexamethasone