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Seizure Medications

The majority of seizures will self-terminate in < 2 minutes and rapid treatment of benzodiazapines or antiseizure medication will not be required. If they don't however, then termination chemically is required:

The eTG guidelines state:

  • clonazepam 1mg (child: 0.25 to 0.5mg) IV, over 2 to 5 minutes, not exceeding 0.5mg/min. Repeat once 15 minutes later if status epilepticus continues
  • diazepam 10 to 20 mg (child: 0.1 to 0.25mg/kg up to 20mg) IV, over 2 to 5 minutes, not exceeding 5mg/min. Repeat once 15 minutes later if status epilepticus continues
  • midazolam 5 to 10mg (child: 0.15 to 0.2mg/kg up to 10mg) IM or IV, over 2 to 5 minutes or midazolam 5 to 10mg (child: 0.2 to 0.3mg/kg up to 10mg) buccally or intranasally. Repeat once 15 minutes later if status epilepticus continues

Midazolam in more detail if you have no institution specific guidelines.

  • Adult

IV 5mg bolus: onset 30 seconds, then 2.5mg at 2-3 min intervals, no maximum but consider other agents when approaching 10-15mg

IM 5mg bolus: onset 2 mins, decreased absorption in the cold, sick and 'shut down' patients 

IN 0.3mg/kg bolus: onset 1-2 mins, (this can be technically difficult in seizing patient)

PR not a recommended midazolam route (note Valium available as Stesolid brand in 5 and 10mg PR dispensing tubes)

Frail, small or elderly 2.5mg bolus, then 1 mg at 2-3 minute intervals, be prepared to support airway and ventilation.

IV 0.15mg/kg bolus, repeated at 5 mins if still fitting

IM 0.15mg/kg bolus

If the seizure continues for 10 minutes despite benzodiazapines, further anticonvulsant loading is required. If the seizure terminates with benzodiazapines within 10 minutes further medication should be discussed with your referral partners. 

The three main second line anticonvulsants have been shown to be equally efficacious by the ESETT trial. These option are:

  • Phenytoin dose is 20mg/kg for adults and children, should be given no faster than 50mg/min due to the increased risk of brady arrhythmia and hypotension. 1g if often not enough for an adult.

Sodium Valproate
  • Sodium valproate 40 mg/kg up to 3000 mg (avoid in pregnancy).
  • Levetiracetam 60 mg/kg up to 4500 mg (preferred in pregnancy)
Phenobarbitone (paediatrics only)
  • Phenobarbitone 10 to 20mg/kg (child: 15 to 20mg/kg) IV, not exceeding 100mg/min

Refractory status epilepticus:

  • RSI and propofol

  • RSI and thiopentone (then use other meds for infusion, propofol, clonazepam, midazolam)

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