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Seizures & Epilepsy — Acute & Long-Term

Registrar quick reference · status epilepticus · first seizure · ASM selection
Compiled Jun 2026
Verify doses locally
Always look for the cause
Decision support only — not a substitute for eTG (neurology), Austroads "Assessing Fitness to Drive," or your neurology team. In any prolonged seizure: check glucose early, hunt the precipitant, and don't under-dose the benzodiazepine. Driving must be addressed and documented. Verify all doses.
1 Status epilepticus — the treatment clock
0 min
5
20
40
Stabilise+ start the clock
ABC · O₂ · IV · glucose
Benzodiazepine×2 — full dose
Lorazepam IV / midazolam IM · repeat once
Second-line ASMany of the three
Levetiracetam / valproate / fosphenytoin
Refractoryanaesthesia
RSI + ICU
SE is defined operationally at 5 minutes of continuous seizing. The three second-line agents are equivalent — ~45% seizure cessation each ESETT — so pick whichever is fastest/safest to give (often levetiracetam) and give it with the second benzo dose, not after a delay. IM midazolam ≥ IV lorazepam when there's no line RAMPART. If the patient isn't waking after seizures stop, think non-convulsive SE → EEG.
2 Status epilepticus — doses & the things people miss

Drug doses

  • BenzoLorazepam 0.1 mg/kg IV (max 4 mg), or midazolam 10 mg IM, or diazepam IV / buccal-IN midazolam. Repeat once at 5–10 min.
  • Levetiracetam60 mg/kg (max 4.5 g)
  • Valproate40 mg/kg (max 3 g) — avoid in pregnancy.
  • Fosphenytoin20 mg PE/kg (max 1.5 g) — avoid in toxic/cardiac seizures.

Don't miss

  • Benzo doseUnder-dosing benzodiazepines is a leading cause of "refractory" SE — give the full dose, repeat once.
  • MetabolicGlucose (+ thiamine first if alcohol/malnourished), Na, Ca, Mg.
  • EclampsiaPregnant/postpartum → magnesium, not the usual ladder.
  • CauseToxic (consider pyridoxine for INH), CNS infection, structural, withdrawal — treat it.
3 First seizure — was it, and do you treat?

Characterise & work up

  • Is it?Distinguish from syncope (incl. convulsive syncope), and from psychogenic non-epileptic seizures.
  • Provoked?Acute symptomatic (hypoglycaemia, hyponatraemia, alcohol withdrawal, drugs, eclampsia) → treat the cause, not long-term ASM.
  • WorkupGlucose/Na/Ca/Mg, ECG (exclude cardiac syncope/long QT), EEG, MRI brain; LP if febrile/immunocompromised.

When to start an ASM

  • DefaultAfter a single unprovoked seizure, don't reflexively treat — risk-stratify recurrence.
  • Treat ifEpileptiform EEG, structural MRI lesion, nocturnal/focal — i.e. ILAE ≥60% recurrence risk = epilepsy after one seizure.
  • EvidenceEarly treatment cuts short-term recurrence but doesn't change long-term remission MESS — a shared decision.
4 Choosing an ASM — by seizure type
Focal epilepsy
Focal onset, with or without secondary generalisation.
Lamotrigine first-line SANAD II; levetiracetam, lacosamide alternatives. Lamotrigine needs slow titration (rash/SJS).
Generalised epilepsy
Idiopathic/genetic generalised (absence, myoclonic, GTC).
Valproate is most effective SANAD II — but see the box below. Levetiracetam or lamotrigine where valproate must be avoided.
Watch the channel blockers
Carbamazepine, oxcarbazepine, phenytoin (and sometimes lamotrigine).
Can worsen absence & myoclonic seizures in genetic generalised epilepsy — don't use them empirically if the syndrome is unclear.
Aim for monotherapy — about half are controlled on the first appropriate drug. Match the drug to the seizure type and the person (childbearing potential, comorbidities, interactions), not just to "an antiepileptic."
5 Special situations & the traps

Valproate & pregnancy

  • AvoidValproate in anyone of childbearing potential — neural-tube defects and major neurodevelopmental harm. Use a pregnancy-prevention framework if unavoidable.
  • InsteadLamotrigine or levetiracetam; high-dose folate; don't stop ASM abruptly; enrol in a pregnancy register.

Driving

  • AdviseMust not drive and must be told — per Austroads "Assessing Fitness to Drive." Document it.
  • PeriodsSeizure-free intervals differ for private vs commercial licences — confirm the exact period against current Austroads.

Don't forget

  • PNESPsychogenic non-epileptic seizures — video-EEG diagnosis; ASMs don't help and can harm.
  • SUDEPCounsel; good seizure control & adherence reduce risk.
  • InteractionsEnzyme inducers (carbamazepine, phenytoin) ↓ OCP/DOAC/others. Valproate raises lamotrigine.
Sources. eTG (neurology — seizures/epilepsy, status epilepticus). NICE NG217 (epilepsies). ILAE operational definitions (epilepsy; status epilepticus). Austroads "Assessing Fitness to Drive" (Australian licensing). Neurocritical Care Society / status epilepticus guidance. TGA/MHRA valproate pregnancy-prevention guidance.   Key trials: ESETT (levetiracetam = valproate = fosphenytoin as second-line, ~45% each); RAMPART (IM midazolam ≥ IV lorazepam prehospital); MESS (immediate vs deferred treatment after first/early seizure); SANAD II (lamotrigine for focal; valproate most effective for generalised).   Caveats: driving seizure-free periods vary by licence class and jurisdiction — confirm current Austroads. Status doses are weight-based with maxima — verify against eTG/local protocol. Match ASM to syndrome and to childbearing potential, not to seizure type alone. Companion to the neuro/acute set (stroke).