What is the first-line treatment for acute seizures?

First-Line Treatment for Acute Seizures

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

Immediate First-Line Treatment Options

When IV access is available:

• IV lorazepam 4 mg at 2 mg/min is the preferred benzodiazepine due to superior efficacy over diazepam (59.1% vs 42.6% seizure termination) and longer duration of action 3, 1, 2
• If seizures continue after 10-15 minutes, administer a second 4 mg dose of lorazepam slowly 2
• IV diazepam is an acceptable alternative if lorazepam is unavailable 3

When IV access is NOT available:

• Intramuscular midazolam is equally efficacious and demonstrates effectiveness in prehospital settings 1
• Intranasal or buccal midazolam are acceptable alternatives showing 88-93% efficacy in stopping seizures within 10 minutes 1
• Rectal diazepam should be administered if other routes are unavailable—IM diazepam is NOT recommended due to erratic absorption 3, 4

Critical Concurrent Actions

Before administering lorazepam:

• Have airway equipment immediately available, as respiratory depression can occur 1, 2
• Check fingerstick glucose immediately and correct hypoglycemia while administering treatment 1, 2
• Monitor vital signs continuously and be prepared to provide respiratory support 1, 2

Second-Line Treatment (If Seizures Continue After Benzodiazepines)

Emergency physicians should treat seizures refractory to appropriately dosed benzodiazepines with a second-line agent—fosphenytoin, levetiracetam, or valproate may be used with similar efficacy. 3

Recommended second-line agents with specific dosing:

• Valproate 30 mg/kg IV over 5-20 minutes: 88% efficacy with 0% hypotension risk—the safest cardiovascular profile 3, 1, 5
• Levetiracetam 30 mg/kg IV over 5 minutes: 68-73% efficacy with minimal adverse effects and no cardiac monitoring requirements 3, 1, 5
• Fosphenytoin 20 mg PE/kg IV at maximum rate of 50 mg/min: 84% efficacy but carries 12% hypotension risk requiring continuous ECG and blood pressure monitoring 3, 1, 5
• Phenobarbital 20 mg/kg IV over 10 minutes: 58.2% efficacy but higher risk of respiratory depression 1, 5

Valproate appears to cause less hypotension than phenytoin while maintaining similar efficacy, making it an excellent first choice among second-line agents. 5

Third-Line Treatment for Refractory Status Epilepticus

If seizures persist despite benzodiazepines and one second-line agent, initiate anesthetic therapy:

• Midazolam infusion (preferred): Loading dose 0.15-0.20 mg/kg IV, then continuous infusion at 1 mg/kg/min, titrated up by 1 mg/kg/min every 15 minutes to maximum 5 mg/kg/min—80% efficacy with 30% hypotension risk 1, 5
• Propofol: 2 mg/kg bolus followed by 3-7 mg/kg/hour infusion—73% seizure control but requires mechanical ventilation 1, 5
• Pentobarbital: 13 mg/kg bolus followed by 2-3 mg/kg/hour infusion—highest efficacy at 92% but carries 77% hypotension risk 1, 5

Critical Pitfalls to Avoid

• Never use phenobarbital as first-line treatment—it performs significantly worse than all other options 1
• Never delay second-line treatment—delaying increases morbidity and mortality 1
• Never use neuromuscular blockers alone—they only mask motor manifestations while allowing continued electrical seizure activity and brain injury 1, 5
• Never skip to third-line agents until benzodiazepines and a second-line agent have been tried 1
• Never put anything in the mouth of a seizing patient or give oral medications during an active seizure 1

Essential Concurrent Management

While administering anticonvulsants, simultaneously search for and treat reversible causes:

• Hypoglycemia, hyponatremia, hypoxia 1, 5, 2
• CNS infection, ischemic stroke, intracerebral hemorrhage 1, 5
• Drug toxicity or withdrawal syndromes 1, 5, 2
• Ensure airway, breathing, and circulation are stabilized before or concurrent with medication administration 1