Drugs used for acute symptomatic seizure
| Drug | Key points |
|---|---|
| Benzodiazepines | Lorazepam 4 mg bolus, repeated after 10 min if necessary. |
| Rectal diazepam and buccal midazolam are alternatives. | |
| Short course of oral clobazam useful in patients with recurrent seizures that do not develop into status epilepticus. | |
| Main side-effects are sedation and respiratory depression – airway management and ventilatory support in a critical care facility may be required. | |
| Phenytoin | Intravenous loading (15 mg/kg over 20 min) effective in terminating tonic-clonic and partial status epilepticus. |
| Cardiac monitoring required (risks of arrhythmias). | |
| Long term side-effects, complex drug interactions and pharmacokinetics make this a less attractive maintenance agent. | |
| Fosphenytoin is considerably more expensive, but has the advantages of fewer injection sites and cardiovascular side effects, and can be given intramuscularly. | |
| Barbiturates (phenobarbital and thiopentone) | Third line agents if benzodiazepines and phenytoin are unsuccessful. |
| Respiratory depression and hypotension necessitate admission to a critical care facility. | |
| Long half-life often results in prolonged ventilation. | |
| Propofol | Primarily used as an anaesthetic agent, but more rapid seizure control, less cardiovascular side effects and shorter half-life than barbiturates. |
| Overly rapid weaning can cause rebound seizure activity. | |
| Sodium valproate | Increasingly favoured over phenytoin in the acute situation, with few side-effects when given rapidly at high doses (25 mg/kg over 10 min).37 |
| Effective for other seizure types (absence, myoclonic). | |
| Should be avoided in patients with liver impairment. | |
| Risk of congenital malformations limits use in women of child-bearing age. | |
| Levetiracetam | Open label studies have demonstrated efficacy of intravenous loading in status epilepticus38 and in critically ill patients with acute symptomatic seizures.39 |
| Usually well tolerated and therapeutic oral dose (1000 mg daily) achievable over several days or quicker. | |
| Can be started orally alongside more aggressive treatment, allowing the withdrawal of phenytoin, barbiturates or propofol more safely. | |
| Useful when trying to avoid drug interactions (eg, patients on warfarin, HIV patients). |