Paediatric Seizure Medicines

Seizure medicines in children serve two purposes: stopping a seizure that lasts more than 5 minutes (status epilepticus), and long-term prevention in epilepsy. Febrile seizures need no maintenance treatment. Treatment of the cause (hypoglycaemia, meningitis, cerebral malaria) takes priority.

Immediate actions. Position, airway, oxygen, check glucose at once, and give 2 mL/kg of 10% glucose if glucose is under 3 mmol/L (under 2.6 mmol/L in neonates). Look for fever, head injury and meningeal signs.

Status epilepticus (seizure over 5 minutes):

• First line (at 5 minutes), one of:
  • Midazolam buccal 0.3 mg/kg (about 2.5 mg at 6 months to 1 year, 5 mg at 1 to 4 years, 7.5 mg at 5 to 9 years, 10 mg at 10 years and over).
  • Midazolam intramuscular 0.2 mg/kg (maximum 10 mg).
  • Lorazepam 0.1 mg/kg intravenously (maximum 4 mg).
  • Diazepam 0.25 to 0.4 mg/kg intravenously (maximum 10 mg) or 0.5 mg/kg rectally (maximum 10 mg).
  Give a second dose after 5 to 10 minutes if the seizure continues. Give only two doses in total, because of respiratory depression.
• Second line (at 20 minutes), one of:
  • Levetiracetam 40 mg/kg intravenously over 5 to 15 minutes (maximum 3 g).
  • Phenytoin 20 mg/kg intravenously over 20 minutes (maximum 2 g, with ECG monitoring).
  • Phenobarbital 20 mg/kg intravenously over 20 minutes, which is first choice in neonates.
  Valproate 40 mg/kg over 10 minutes (maximum 3 g) is an alternative. Avoid it in infants under 2 years, suspected metabolic or mitochondrial disease and liver disease.
• Third line: anaesthetic induction with intubation under specialist care.
• Infants under 18 months with seizures not responding: pyridoxine 100 mg intravenously once, with monitoring.

Maintenance is chosen by seizure type and started under specialist direction:

• Focal seizures: carbamazepine 5 mg/kg/day in two divided doses, titrated to 10 to 20 mg/kg/day; or levetiracetam 10 mg/kg/day in two doses, titrated to 30 to 60 mg/kg/day.
• Generalised seizures: valproate 10 mg/kg/day titrated to 20 to 40 mg/kg/day (avoided in girls and women of childbearing potential), or levetiracetam or lamotrigine with slow titration.
• Absence: ethosuximide 10 mg/kg/day in two doses, titrated to 20 mg/kg/day, or valproate.
• Where choices are limited: phenobarbital 3 to 5 mg/kg/day once daily.

Neonates. Phenobarbital 20 mg/kg load then 3 to 5 mg/kg daily, with level 15 to 40 mg/L.

Kidney impairment. Reduce levetiracetam by 50% when creatinine clearance is under 50 mL/min/1.73 m2.

Liver impairment. Avoid valproate; reduce phenobarbital.

Interactions. Carbamazepine, phenytoin and phenobarbital induce enzymes and lower levels of contraceptives, antiretrovirals and antimalarials.

Special groups. Adolescent girls need valproate avoided and folic acid 5 mg daily before pregnancy. In East Africa, cerebral malaria needs intravenous artesunate and treatment for hypoglycaemia, and neurocysticercosis is a common cause of focal seizures.

Monitoring. During loading: heart rate, blood pressure, respiratory rate and SpO2. For maintenance: sodium and liver enzymes at baseline, blood count on carbamazepine and valproate, and drug levels for phenytoin and phenobarbital. Watch for rash (stop carbamazepine and lamotrigine at once if severe).

Referral and escalation. Escalate after two benzodiazepine doses or for seizure beyond 20 minutes, first afebrile seizure under 1 year, signs of raised intracranial pressure, and suspected metabolic or infectious cause.

Stopping. Withdraw maintenance over at least 3 months after 2 seizure-free years, never abruptly.