What is the appropriate medication and dose for stopping a seizure in an adult patient?

Immediate Treatment for Active Seizures

Administer IV lorazepam 4 mg at 2 mg/min immediately as first-line treatment for any actively seizing adult patient. 1, 2

First-Line Treatment: Benzodiazepines (0-5 minutes)

IV lorazepam is the gold standard first-line agent, demonstrating 65% efficacy in terminating status epilepticus and superior performance compared to diazepam (59.1% vs 42.6% seizure termination). 1, 3 Lorazepam has a longer duration of action than other benzodiazepines, making it the preferred choice. 1

Dosing Protocol:

• Lorazepam 4 mg IV at 2 mg/min 1
• May repeat once after 5 minutes if seizure continues 1
• Have airway equipment immediately available before administration due to respiratory depression risk 1

Alternative Routes When IV Access Unavailable:

• IM midazolam 10 mg (non-inferior to IV lorazepam with 97% relative efficacy) 1
• Intranasal midazolam (onset 1-2 minutes, peak effect 3-4 minutes) 1
• Buccal midazolam (rapidly absorbed through buccal mucosa) 4
• Rectal diazepam 0.5 mg/kg (avoid IM diazepam due to erratic absorption) 1

Second-Line Treatment: If Seizures Continue After Benzodiazepines (5-20 minutes)

If seizures persist after adequate benzodiazepine dosing, immediately escalate to one of these second-line agents. The choice depends on speed requirements and cardiovascular stability. 1, 5

Valproate (Fastest Option - RECOMMENDED)

• Dose: 30 mg/kg IV over 5-20 minutes (can administer at 40 mg/min) 1, 5
• Efficacy: 88% seizure control 1, 5
• Median time to seizure termination: 7.0 minutes (fastest of all agents) 5
• Hypotension risk: 0% (major advantage over phenytoin) 1, 5
• Contraindication: Women of childbearing potential (significant teratogenic risk) 1

Levetiracetam (Safest Cardiovascular Profile)

• Dose: 30 mg/kg IV over 5 minutes (maximum 2500-3000 mg) 1, 5
• Efficacy: 68-73% 1, 5
• Median time to seizure termination: 10.5 minutes 5
• No cardiac monitoring required - minimal cardiovascular effects 1
• Ideal for elderly patients 1

Fosphenytoin (Traditional but Slower)

• Dose: 20 mg PE/kg IV at maximum rate of 50 mg/min 1
• Efficacy: 84% 1
• Median time to seizure termination: 11.7 minutes (slowest option) 5
• Hypotension risk: 12% - requires continuous ECG and blood pressure monitoring 1
• 95% of neurologists still recommend this for benzodiazepine-refractory seizures 1

Phenobarbital (Higher Respiratory Depression Risk)

• Dose: 20 mg/kg IV over 10 minutes 1
• Efficacy: 58.2% (lowest of second-line agents) 1
• Higher risk of respiratory depression and hypotension 1

Third-Line Treatment: Refractory Status Epilepticus (20+ minutes)

Refractory status epilepticus is defined as seizures continuing despite benzodiazepines and one second-line agent. Initiate continuous EEG monitoring at this stage. 1

Midazolam Infusion (First Choice for RSE)

• Loading dose: 0.15-0.20 mg/kg IV 1, 6
• Continuous infusion: 1 mg/kg/min, titrate up by 1 mg/kg/min every 15 minutes to maximum 5 mg/kg/min 1, 6
• Efficacy: 80% 1
• Hypotension risk: 30% (lowest among anesthetic agents) 1
• Requires mechanical ventilation 1

Propofol (Shorter Ventilation Time)

• Loading dose: 2 mg/kg bolus 1
• Continuous infusion: 3-7 mg/kg/hour 1
• Efficacy: 73% 1
• Hypotension risk: 42% 1
• Requires mechanical ventilation but shorter duration than barbiturates (4 days vs 14 days) 1

Pentobarbital (Highest Efficacy, Highest Risk)

• Loading dose: 13 mg/kg 1
• Continuous infusion: 2-3 mg/kg/hour 1
• Efficacy: 92% (highest of all agents) 1
• Hypotension risk: 77% - nearly universal vasopressor requirement 1
• Prolonged mechanical ventilation (mean 14 days) 1

Critical Simultaneous Actions

While administering anticonvulsants, immediately search for and correct reversible causes: 1

• Check fingerstick glucose and correct hypoglycemia 1
• Assess for hyponatremia 1
• Evaluate for drug toxicity or withdrawal syndromes 1
• Consider CNS infection, stroke, or intracerebral hemorrhage 1
• Ensure adequate oxygenation 1

Special Population Considerations

Elderly Patients (Age ≥60):

• Midazolam: Maximum 1.5 mg over 2 minutes, wait 2+ minutes before additional dosing, total dose rarely exceeds 3.5 mg 6
• Levetiracetam preferred due to no cardiac monitoring requirements 1
• Require 50% less benzodiazepine than younger patients 6

Maintenance Dosing After Seizure Control:

• Levetiracetam: 30 mg/kg IV every 12 hours (maximum 1500 mg per dose) for convulsive SE 1
• Levetiracetam: 15 mg/kg IV every 12 hours (maximum 1500 mg per dose) for non-convulsive SE 1
• Load with long-acting anticonvulsant during anesthetic infusion before tapering 1

Critical Pitfalls to Avoid

• Never use neuromuscular blockers alone (rocuronium) - they only mask motor manifestations while allowing continued electrical seizure activity and brain injury 1
• Never skip to third-line agents until benzodiazepines and a second-line agent have been tried 1
• Never delay anticonvulsant administration for neuroimaging in active status epilepticus 1
• Never use IM diazepam due to erratic absorption - use rectal route instead 1
• Avoid valproate in women of childbearing potential without explicit contraceptive measures 1, 2

Monitoring Requirements for Anesthetic Agents

• Continuous EEG monitoring to guide titration and detect non-convulsive seizures 1
• Continuous blood pressure monitoring - hypotension common with all anesthetic agents 1
• Prepare for mechanical ventilation before initiating anesthetic agents 1
• Have vasopressors immediately available (norepinephrine or phenylephrine) 1
• Continue EEG monitoring 24-48 hours after discontinuation - breakthrough seizures occur in >50% of patients 1