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Status epilepticus

Emergencies

Treat any convulsive seizure lasting 5 minutes or more, or 3 or more in an hour.

Check glucose early, and think about eclampsia in anyone pregnant or recently delivered.

0:00

Start when the event began (or now)

  1. 0′

    First minutes

    • Time it. ABCDE, protect from injury, high-flow oxygen.
    • Capillary glucose; IV access; bloods including antiseizure drug levels.
  2. 5′

    Still seizing at 5 minutes

    • IV lorazepam, or buccal midazolam if no IV access.
  3. 15′

    Still seizing 10 minutes after the first dose

    • Second benzodiazepine dose (two doses maximum, including pre-hospital).
    • Call the anaesthetist.
  4. 20′

    Still seizing after two doses

    • Second-line: levetiracetam, phenytoin or sodium valproate over about 10 minutes.
  5. 40′

    Refractory

    • General anaesthesia in critical care.

Act now

  1. 1

    High-flow oxygen; nasopharyngeal airway if needed — nothing between the teeth.

  2. 2

    IV access: IV lorazepam. No IV access: buccal midazolam (or rectal diazepam).

  3. 3

    Still seizing 10 minutes after the first benzodiazepine: give a second dose once. Do not give more than two doses in total, including any pre-hospital dose.

  4. 4

    Capillary glucose under 4 mmol/L: treat. Give IV thiamine first if alcohol excess or malnutrition is possible.

Assess

  • Time of onset — get someone to time it. ABCDE; protect from injury; recovery position once possible.
  • Known epilepsy? Missed or recently changed antiseizure drugs? Alcohol, drug withdrawal or overdose, head injury, infection, metabolic cause.

Investigations

  • Glucose, venous gas, U&E, calcium, magnesium, FBC, LFT, CK, antiseizure drug levels, toxicology, pregnancy test.
  • CT head if a first seizure, focal signs, head injury, anticoagulated, or not recovering as expected.

Manage

  • Still seizing after two benzodiazepine doses: start a second-line drug — levetiracetam, phenytoin or sodium valproate.
  • Call the anaesthetist when second-line treatment starts. If seizures continue, the next step is general anaesthesia in critical care.
  • Once stopped: recovery position, neuro obs, restart usual antiseizure drugs, look for the cause.

Escalate when

  • Seizing despite second-line treatment, airway compromise, or not regaining consciousness: anaesthetist and critical care.
  • Eclampsia: obstetric emergency team.

Doses and prescribing

Lorazepam

4 mg IV (0.1 mg/kg if under 40 kg), repeated once after 10 minutes if needed.

Midazolam

10 mg buccal if no IV access.

Levetiracetam

60 mg/kg IV (max 4.5 g) over 10 minutes.

Phenytoin

20 mg/kg IV at no more than 50 mg/minute, with ECG and BP monitoring.

Sodium valproate

40 mg/kg IV (max 3 g) over about 10 minutes. Avoid in pregnancy and in women and girls who could become pregnant unless no alternative; avoid in liver disease.

Thiamine (Pabrinex)

2 pairs of ampoules IV before glucose if alcohol excess or malnutrition is suspected.

Check the BNF and your local formulary before prescribing.

Written to current guidance (NICE NG217) · sources checked 14 Nov 2026. We watch NICE for updates weekly.

Sources (2)

Reviewed by Aboodee Alhasso, MPharm MRCPharm IP on 14 Nov 2026

Calculators for this

For healthcare professionals, as an aid to clinical judgement — not a substitute for it. Follow your local policy and ask a senior when in doubt.