The primary objectives of this study are to examine whether augmented renal clearance (ARC) compromises renally eliminated drug therapeutic serum concentrations in patients with traumatic brain injury (TBI) and to estimate the optimal dose needed to achieve therapeutic serum concentrations of the probe medication levetiracetam in patients with TBI.

Purpose: The primary objectives of this study are to examine whether augmented renal clearance compromises renally eliminated drug therapeutic serum concentrations in patients with traumatic brain injury (TBI) and to estimate the optimal dose needed to achieve therapeutic serum concentrations of the probe medication levetiracetam in patients with TBI.

Participants: The population will be comprised of patients with traumatic brain injury requiring levetiracetam for seizure prophylaxis admitted to the neurosciences intensive care unit

Procedures (methods): This is a multi-center, prospective, non-randomized pharmacokinetic study in patients with TBI. In patients who meet the inclusion criteria, a 12-hour urine collection for measuring creatinine clearance levetiracetam urine concentrations will be performed daily for 7 days. Serum levetiracetam concentrations will be obtained twice daily for 7 days.

Inclusion Criteria:

1. Adults ≥ 18 years
2. Patients with TBI requiring levetiracetam for seizure prophylaxis
3. Anticipated length of stay in the SICU or NSICU > 48 hours
4. Informed consent provided by the patient's designated medical proxy

Exclusion Criteria:

1. Pregnancy
2. Patients with renal dysfunction (CKD stages 3 - 5 and/or SCr > 1.4 mg/dL)
3. Patients receiving renal replacement therapy
4. Brain death or suspected imminent brain death within the next 48 hours
5. Patients with history of nephrectomy or renal transplant

40 patients with traumatic brain injury requiring levetiracetam admitted to the University of North Carolina Intensive Care Unit and University of Kentucky Chandler Medical Center Intensive Care Unit