The aim of the study is to describe the concentrations of Ceftriaxone at the steady state, in patients treated for meningitis, to determine pharmacokinetic parameters at high dose in this population. Additionally, we aimed to detect adverse effect, especially neurological trouble related to Ceftriaxone toxicity.

Day 0 : onset of treatment by Ceftriaxone, following usual therapeutic process (French Guideline) From Day 0 to Day 4 : inclusion, clinical and biological data collection, electroencephalogram at baseline.

Two samples for ceftriaxone concentration monitoring :

• Trough concentration of ceftriaxone at steady state
• A random sample (population PK) At the end of ceftriaxone treatment : assessment of tolerance and efficacy of the treatment.

Inclusion Criteria:

• Hospitalized adults patients,
• age equal or above 18
• Patients with Community or surgical acquired neurological infections, meningitis and others
• Prescription of ceftriaxone >75mg/kg/d or >4g/d -
• Subjects affiliated to French health insurance (social security)
• Informed consent form signed

Exclusion Criteria:

- Patient under guardianship