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Seizure Prophylaxis After Neurological Injury: A Critical Care Perspective

Explore the guidelines and recommendations for seizure prophylaxis in patients with severe traumatic brain injury (TBI), intracerebral hemorrhage..

Introduction

Seizure prophylaxis is a crucial consideration after neurological injuries such as traumatic brain injury (TBI), intracerebral hemorrhage (ICH), and subarachnoid hemorrhage (SAH). As a critical care pharmacist, understanding when and how to administer seizure prophylaxis is vital for optimizing patient outcomes.

Who should receive seizure prophylaxis?

Severe Traumatic Brain Injury (TBI)

  • Continue seizure prophylaxis after a severe TBI, defined by a Glasgow Coma Scale score of 3 to 8.
  • Approximately 10% of TBI patients experience seizures.
  • Seizure prophylaxis can reduce the occurrence of seizures within the first week after injury.

Intracerebral Hemorrhage (ICH) and Subarachnoid Hemorrhage (SAH)

  • Seizure prophylaxis is generally not recommended after ICH or SAH due to a lack of consistent benefit. Limited data suggest worse outcomes with routine use in these patients.
  • Despite general guidelines, seizure prophylaxis may be considered in specific cases, such as a bleed in the temporal lobe. This practice remains a topic of debate among specialists.

What Medications Should Be Used?

Phenytoin vs. Levetiracetam

  • Both phenytoin and levetiracetam are effective in reducing early seizures.
  • Levetiracetam is often preferred due to its fewer side effects and drug interactions.
  • Initiate seizure prophylaxis as soon as possible, ideally within the first 24 hours after injury.
  • Dosing ↪ you can review the PDR website or Epocrates "free access"..
    • Levetiracetam: Standard doses range from 500 mg to 1,000 mg twice daily (BID). If possible, administer orally.
      • If using intravenous (IV) levetiracetam, consider IV push maintenance doses for efficiency instead of piggyback infusions.
    • Phenytoin: Consider loading doses, especially if using phenytoin.
      • Loading dose: IV: 17 to 20 mg/kg at a rate of ≤50 mg/minute; maximum dose: 2 g; begin maintenance dose 8 to 12 hours after loading dose.
      • Maintenance dose: IV, Oral: 100 mg every 8 hours or 5 mg/kg/day (round to the nearest 100 mg) divided every 8 hours. To ensure optimal absorption, individual oral doses should not exceed 400 mg. Note: Duration of prophylaxis varies, generally short-term use (eg, ~7 days).

When to Stop Seizure Prophylaxis?

  • Typically, discontinue seizure prophylaxis after 7 days.
  • In cases of SAH, stop prophylaxis sooner if the aneurysm has been secured.
  • Add a stop date to your documentation or include seizure prophylaxis in your list of medications to assess at discharge or transfer. This ensures that prophylaxis is not continued longer than intended.

Take-home points
  1. Continue seizure prophylaxis in severe TBI cases; it’s crucial in the first week.
  2. Avoid routine seizure prophylaxis in ICH/SAH patients; consider it only in specific cases.
  3. Favor levetiracetam for fewer side effects; start prophylaxis promptly.
  4. Be vigilant about stopping seizure prophylaxis after the appropriate duration.

References

  1. Khan NR, VanLandingham MA, Fierst TM, et al. Should Levetiracetam or Phenytoin Be Used for Posttraumatic Seizure Prophylaxis? A Systematic Review of the Literature and Meta-analysis. Neurosurgery. 2016;79(6):775-782. doi:10.1227/NEU.0000000000001445
    2. Show more references

Keywords: Seizure prophylaxis, traumatic brain injury, TBI, intracerebral hemorrhage, ICH, subarachnoid hemorrhage, SAH, phenytoin, levetiracetam, critical care, neurological injury

Seizure Prophylaxis After Neurological Injury: A Critical Care Perspective
Senior clinical pharmacist, "Pharmacy Practice Department, Tanta University Hospital, Egypt". Medical content writer.