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Neurology

Status Epilepticus

Convulsive status epilepticus is a self-sustaining seizure state in which gamma-aminobutyric acid (GABA) inhibition fails, so seizures no longer stop spontaneously and grow harder to treat every minute.

In a nutshell

Convulsive status epilepticus is a seizure lasting 5 minutes or more, or repeated seizures without recovery in between. In an adult, give lorazepam 4 mg intravenously (buccal midazolam 10 mg if there is no line), repeat once at 5 to 10 minutes, then a second-line infusion, then anaesthesia.

Classic presentation

A known epileptic arrives mid-convulsion; the paramedics report continuous seizing for eight minutes and no eye opening since it began.

Key points

  • Most tonic-clonic seizures stop within 2 to 3 minutes, which is why one still running at 5 minutes is treated as status.
  • Thirty minutes is when neuronal injury begins, not when to start treatment. That is the whole reason the definition changed.
  • Benzodiazepines lose potency as status continues because inhibitory receptors are withdrawn from the synapse, so speed matters more than drug choice.
  • The adult levetiracetam 60 mg/kg loading dose is unlicensed and comes from UK hospital protocols; the BNF lists only a paediatric status dose.
  • Paediatric: lorazepam 100 micrograms/kg intravenously (maximum 4 mg); buccal midazolam 10 mg at 10 to 17 years, 7.5 mg at 5 to 9, 5 mg at 1 to 4.
  • Send a pregnancy test in any woman of childbearing age: eclampsia changes the drug from an antiseizure medicine to magnesium sulfate.
  • After the seizure, check creatine kinase, temperature and blood gas for rhabdomyolysis, hyperthermia and lactic acidosis.

First-line investigation

Capillary glucose at the bedside, alongside an airway, breathing, circulation, disability, exposure (ABCDE) assessment and continuous monitoring; below 4.0 mmol/L is hypoglycaemia and is corrected first.

Management

Resuscitate and start the clock (adult doses)

  • Write down the seizure start time. ABCDE, high-flow oxygen, continuous monitoring, intravenous or intraosseous access. Protect the head, do not restrain, put nothing in the mouth.2,7
  • Check capillary glucose. If below 4.0 mmol/L give 100 mL of 20% glucose intravenously over 15 minutes, or glucagon 1 mg intramuscularly if there is no access.4
  • If alcohol excess or malnutrition is possible, follow the glucose with intravenous thiamine 500 mg (two pairs of high-potency vitamin B and C ampoules) over 30 minutes.7,10,9

Benzodiazepine, twice and no more (adult doses)

  • Adult, with a line: lorazepam 4 mg by slow intravenous injection into a large vein. Without one: buccal midazolam 10 mg, or rectal diazepam 10 to 20 mg.11,12,13
  • Repeat the same dose once, 5 to 10 minutes later. Two doses is the ceiling, and a dose given by a carer or paramedic before arrival counts as one.2,3
  • Follow an individualised emergency plan instead if one is immediately available. Watch saturations and blood pressure after each dose: both benzodiazepines cause respiratory depression.2,12

Second-line infusion after two benzodiazepines (adult doses)

  • Adult: levetiracetam 60 mg/kg (maximum 4.5 g) in 100 mL sodium chloride 0.9% over 10 minutes. NICE ranks none of the three; levetiracetam is quickest with fewest adverse effects.7,2,3
  • Phenytoin 20 mg/kg (maximum 2 g) at no more than 50 mg/minute, or 25 mg/minute in older people and cardiac disease. Continuous ECG and blood pressure monitoring are essential.14,15
  • Adult: sodium valproate 40 mg/kg (maximum 3 g) over 10 minutes in the cited pathway. If the approved local chart uses 25 mg/kg, follow it exactly; never top up. Avoid if pregnancy is possible.7,3,16

Refractory status, the cause, and the aftermath (adult doses)

  • Still seizing after the second-line infusion, or past 30 minutes: rapid sequence induction, intubation and ventilation in intensive care. Alert the anaesthetist when you start the infusion.7,2
  • NICE permits phenobarbital as the third-line alternative on expert advice. BNF adult dose 10 mg/kg intravenously (maximum 1 g) at up to 100 mg/minute, with continuous electroencephalogram (EEG) monitoring.17,2
  • Eclampsia: magnesium sulfate 4 g intravenously over 5 to 15 minutes, then 1 g/hour for 24 hours. Suspected meningitis: adult ceftriaxone 2 g intravenously within 1 hour.5,6,18
  • If consciousness does not return once convulsions stop, request urgent EEG for status without prominent motor signs (non-convulsive status) rather than accepting a postictal state.7,2
  • After loading, continue the drug that worked: adult phenytoin 100 mg every 6 to 8 hours; protocols commonly use levetiracetam 1 g or valproate 800 mg 8-hourly.14,3

Exam traps

  • Five minutes, not thirty. The 30-minute figure is when neuronal injury starts, not when treatment starts.
  • Two benzodiazepine doses only. The dose the paramedics gave in the ambulance is one of your two.
  • Convulsions stopping is not the same as recovery. If they do not wake, ask for an urgent EEG.
  • Phenytoin above 50 mg/minute causes hypotension, arrhythmia and asystole; it needs continuous ECG and blood pressure monitoring.
  • In pregnancy or after delivery, treat an eclamptic seizure with magnesium sulfate; diazepam and phenytoin are not substitutes.
  • Sodium valproate is a NICE second-line option but not for someone who could become pregnant: reach for levetiracetam.
  • Do not do a lumbar puncture in a seizing patient with suspected meningitis. Give ceftriaxone and image first.

Key sources

  1. International League Against Epilepsy (ILAE), Epigraph: What's new in status epilepticus, Professor Eugen Trinka (ILAE Epigraph volume 27 issue 3, summer 2025. Source for the two operational time points: 5 minutes as the point at which a tonic-clonic seizure will not stop spontaneously and treatment must begin, and about 30 minutes as the point of neuronal injury)
  2. NICE NG217, Epilepsies in children, young people and adults: treating status epilepticus, repeated or cluster seizures, and prolonged seizures (NICE guideline NG217, section 7. Governing UK guidance for the 5-minute treatment threshold, the benzodiazepine sequence, intravenous levetiracetam, phenytoin or sodium valproate as second line, and phenobarbital or general anaesthesia under expert guidance)Published 27 Apr 2022 | Updated 25 Nov 2025
  3. Doncaster and Bassetlaw Teaching Hospitals NHS Foundation Trust, Adult Treatment Protocol for Convulsive Status Epilepticus (English NHS trust protocol dated 13 December 2023. Source for the explicit ceiling of two doses of lorazepam 4 mg in 24 hours, and corroboration of levetiracetam 60 mg/kg (maximum 4.5 g) and sodium valproate 40 mg/kg (maximum 3 g))Updated 13 Dec 2023
  4. Joint British Diabetes Societies for Inpatient Care (JBDS), The Hospital Management of Hypoglycaemia in Adults with Diabetes Mellitus (JBDS 01, revised January 2023. Source for hypoglycaemia below 4.0 mmol/L, 100 mL of 20% glucose or 200 mL of 10% glucose intravenously over 15 minutes, and glucagon 1 mg intramuscularly when there is no access)Updated 1 Jan 2023
  5. NICE NG133, Hypertension in pregnancy: diagnosis and management (Source for eclampsia treatment: magnesium sulfate 4 g intravenously over 5 to 15 minutes then 1 g/hour for 24 hours, a further 2 to 4 g for recurrent fits, and the instruction not to use diazepam, phenytoin or other anticonvulsants as an alternative)
  6. NICE NG240, Meningitis (bacterial) and meningococcal disease: recognition, diagnosis and management (Published 2024, updates and replaces CG102. Source for intravenous antibiotics within 1 hour of arrival and for the contraindications to lumbar puncture, including seizures, focal neurological signs and a Glasgow Coma Scale score of 9 or less)
  7. NHS Highland, Prolonged seizure and status epilepticus in adults (secondary care), TAM286 (NHS Scotland Right Decision Service, last reviewed 1 April 2026. Adult protocol source for levetiracetam 60 mg/kg (maximum 4500 mg), sodium valproate 40 mg/kg (maximum 3000 mg), phenytoin 20 mg/kg (maximum 2000 mg) at 50 mg/minute, intravenous thiamine 500 mg after glucose, anaesthetic escalation timing and urgent EEG)Updated 1 Apr 2026
  8. NHS Ayrshire and Arran Medicines, Management of Status Epilepticus (UK NHS adult guideline, reviewed August 2022 with a minor update in October 2024. Cited only for the definition of convulsive status epilepticus as continuing or recurrent seizures over 5 minutes and for its reported mortality of 16 to 39%)Updated 1 Oct 2024
  9. NHS Greater Glasgow and Clyde Medicines, The Management of Generalised Convulsive Status Epilepticus in Adults (UK NHS adult flowchart, August 2024. Source for 100 mL of 20% glucose intravenously for suspected hypoglycaemia, thiamine as two pairs of high-potency ampoules where alcohol excess or impaired nutrition is suspected, and the staged 0 to 60 minute timings)Updated 1 Aug 2024
  10. Pabrinex / Vitamin B and C Intravenous High Potency, Summary of Product Characteristics, electronic medicines compendium (UK product information, text revised July 2025. Source for thiamine 250 mg per pair of ampoules, dilution in 50 to 100 mL of sodium chloride 0.9% or glucose 5%, and infusion over 30 minutes)
  11. BNF, Lorazepam (Status epilepticus dosing: adult and child 12 to 17 years 4 mg by slow intravenous injection, repeated once 5 to 10 minutes later if required; child 1 month to 11 years 100 micrograms/kg (maximum 4 mg per dose) on the same schedule; give into a large vein)
  12. BNF, Midazolam (Status epilepticus dosing by buccal administration: adult and child 10 to 17 years 10 mg, repeated once 5 to 10 minutes later if required; child 5 to 9 years 7.5 mg; child 1 to 4 years 5 mg; child 3 to 11 months 2.5 mg)
  13. BNF, Diazepam (Status epilepticus dosing: adult 10 to 20 mg rectally (10 mg in the elderly), repeated once 5 to 10 minutes later if required; adult 10 mg by intravenous injection at no more than 5 mg/minute, repeated once after 10 minutes)
  14. BNF, Phenytoin (Status epilepticus, adult: loading dose 20 mg/kg for one dose (maximum 2 g) by slow intravenous injection or infusion, then maintenance 100 mg every 6 to 8 hours. Give into a large vein at no more than 50 mg/minute, with 25 mg/minute or lower in the elderly and in heart disease)
  15. Phenytoin Sodium 50 mg/mL Solution for Injection, Summary of Product Characteristics, electronic medicines compendium (UK product information, text revised 7 July 2026. States that intravenous administration should not exceed 50 mg/minute, that hypotension and fatal cardiotoxic reactions including asystole follow rapid administration, and that continuous ECG and blood pressure monitoring is essential)Updated 7 Jul 2026
  16. MHRA, Valproate: reproductive risks (UK regulatory guidance. Valproate must not be given to a woman or girl able to have children unless the Pregnancy Prevention Programme conditions are met, and must not be started in any patient under 55 years unless two specialists agree and a risk acknowledgement form is completed)Published 10 Jun 2025 | Updated 23 Sept 2025
  17. BNF, Phenobarbital (Status epilepticus, adult: 10 mg/kg by intravenous injection (maximum 1 g per dose). Dilute 1 in 10 with water for injections and give at no more than 100 mg/minute)
  18. BNF, Ceftriaxone (Bacterial meningitis and meningococcal disease, adult: 2 g every 12 hours by intravenous infusion or injection, alternatively 4 g once daily)
  19. BNF, Levetiracetam (Convulsive status epilepticus, on expert advice: child 40 mg/kg for one dose (maximum 3 g) by intravenous infusion. The BNF monograph carries no adult status epilepticus dose, so the adult 60 mg/kg loading dose is taken from UK NHS hospital protocols. Renal maxima for continuing treatment are also given here)

This page is exam revision material, not medical advice, and must not be used for patient care. Always check drug doses against the BNF and current guidance. Full disclaimer.