What is the first line of treatment for a patient experiencing a seizure?

First-Line Treatment for Active Seizures

Administer intravenous lorazepam 4 mg at 2 mg/min immediately for any patient actively seizing—this is the definitive first-line treatment with Level A evidence and 65% efficacy in terminating status epilepticus. 1, 2

Immediate Actions (Within First 60 Seconds)

• Check fingerstick glucose immediately and correct hypoglycemia while administering lorazepam, as this is a rapidly reversible cause 1
• Have airway equipment at bedside before administering lorazepam, as respiratory depression can occur 1, 2
• Establish IV access if available—this is the preferred route for benzodiazepine administration 3

First-Line Treatment Algorithm

If IV Access Available:

• Lorazepam 4 mg IV at 2 mg/min is preferred over diazepam (59.1% vs 42.6% seizure termination rate) 1
• If seizures continue after 10-15 minutes, repeat lorazepam 4 mg IV 2
• Maximum total dose: 8 mg lorazepam 2

If IV Access NOT Available:

• Administer rectal diazepam as the recommended alternative 3
• Intramuscular midazolam is non-inferior to IV lorazepam and may be used 1, 4
• Never use intramuscular diazepam due to erratic absorption 3
• IM phenobarbital may be considered only when rectal diazepam is not possible due to medical or social reasons 3

Second-Line Treatment (If Seizures Continue After Adequate Benzodiazepines)

Administer ONE of the following second-line agents immediately—do not delay for neuroimaging: 1

Preferred Options (Listed by Safety Profile):

1. Valproate 20-30 mg/kg IV over 5-20 minutes

   • 88% efficacy with 0% hypotension risk 1, 5
   • Superior safety profile compared to phenytoin 5

2. Levetiracetam 30 mg/kg IV over 5 minutes

   • 68-73% efficacy with minimal cardiovascular effects 1, 5
   • No cardiac monitoring required, making it ideal for elderly patients 1

3. Fosphenytoin 20 mg PE/kg IV at maximum 50 mg/min

   • 84% efficacy but 12% hypotension risk 1, 5
   • Requires continuous ECG and blood pressure monitoring 5
   • Most widely available second-line agent (95% of neurologists use it) 5

4. Phenobarbital 20 mg/kg IV over 10 minutes

   • 58.2% efficacy but higher risk of respiratory depression 1, 5

Critical Pitfalls to Avoid

• Never use carbamazepine for acute seizure termination—it has no role in status epilepticus and is not mentioned in any treatment guidelines 1
• Never use neuromuscular blockers alone (such as rocuronium)—they only mask motor manifestations while electrical seizure activity and brain injury continue 5
• Never skip directly to third-line agents (pentobarbital, propofol) until benzodiazepines and one second-line agent have been tried 5
• Never delay anticonvulsant administration for neuroimaging in active status epilepticus—CT scanning can be performed after seizure control 1

Simultaneous Evaluation for Reversible Causes

While administering treatment, immediately search for and correct: 1, 5

• Hypoglycemia (check fingerstick glucose)
• Hyponatremia and other electrolyte abnormalities
• Hypoxia
• Drug toxicity or withdrawal syndromes (especially alcohol, benzodiazepines)
• CNS infection (meningitis, encephalitis)
• Ischemic stroke or intracerebral hemorrhage
• Metabolic derangements

Refractory Status Epilepticus (If Seizures Continue Despite Above)

Definition: Seizures continuing despite benzodiazepines and one second-line agent 5

Initiate continuous EEG monitoring at this stage 5

Third-Line Anesthetic Agents:

1. Midazolam infusion (first choice)

   • Loading: 0.15-0.20 mg/kg IV 5
   • Infusion: 1 mg/kg/min, titrate up to max 5 mg/kg/min 5
   • 80% efficacy with 30% hypotension risk 5

2. Propofol

   • Loading: 2 mg/kg bolus 5
   • Infusion: 3-7 mg/kg/hour 5
   • 73% efficacy, requires mechanical ventilation 5

3. Pentobarbital (most effective but highest risk)

   • Loading: 13 mg/kg 5
   • Infusion: 2-3 mg/kg/hour 5
   • 92% efficacy but 77% hypotension risk 5

Special Populations

Febrile Seizures in Children:

• Simple febrile seizures: Follow local fever management protocols and observe for 24 hours—do not give prophylactic antiepileptics 3
• Complex febrile seizures: Admit for inpatient observation and perform appropriate investigations (blood tests, lumbar puncture) 3

Women of Childbearing Age:

• Avoid valproate if possible due to teratogenic risks 3
• Consider levetiracetam or lamotrigine as alternatives 1