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Benzodiazepine Pregnancy: D — neonatal withdrawal with prolonged use; use for status epilepticus

Lorazepam

Brand names: Ativan

Adult dose

Dose: 4mg IV over 30–60 sec
Route: IV / IM
Frequency: Repeat 4mg after 10 min if seizure continues
Max: 8mg in acute status epilepticus
Store in refrigerator — deteriorates at room temperature. IM: 4mg if IV unavailable. If IV unavailable and buccal/IN midazolam not available, IM diazepam 10mg is alternative.

Paediatric dose

Dose: 0.1 mg/kg
Route: IV
Frequency: Single dose; repeat after 10 min if needed
Max: 4mg
Concentration: 4 mg/ml

Dose adjustments

Renal

No dose adjustment required.

Hepatic

Reduce dose in severe hepatic impairment.

Paediatric weight-based calculator

Clinical pearls

  • First-line IV benzodiazepine for status epilepticus — longer duration of action (4–6h) vs diazepam (15–30 min). No active metabolite accumulation.
  • When IV unavailable: buccal/intranasal/IM midazolam is preferred first-line out-of-hospital and for children.
  • After 2 doses of benzodiazepine with no response → escalate to second-line: levetiracetam 40mg/kg IV or sodium valproate 30–40mg/kg IV.
  • Requires refrigeration — check expiry and storage before use.

Contraindications

  • Respiratory depression or apnoea
  • Acute narrow-angle glaucoma
  • Myasthenia gravis

Side effects

  • Respiratory depression — most significant risk, especially IV
  • Hypotension
  • Anterograde amnesia
  • Sedation
  • Paradoxical agitation (elderly)

Interactions

  • CNS depressants: additive respiratory depression
  • Flumazenil: reversal — 0.2mg IV increments to max 1mg
  • Valproate: may inhibit lorazepam glucuronidation — increased levels

Monitoring

  • Respiratory rate
  • SpO₂
  • ECG
  • level of consciousness
  • seizure recurrence

Reference: BNFc; NICE CG137 Epilepsies; CONVULSE Trial; NICE BNF 84. Verify against your local formulary and the latest BNF before prescribing.

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