Anti-convulsants used in treating status epilepticus
| Medication | Doses | Kinetics | Complications | Comments |
|---|---|---|---|---|
| Phenytoin | 15-20 mg/kg <50 mg/min Maintenance level >20 µg/mL |
Effect in 10-30 min Peak effect in 1 h Elimination half-life 24-48 h |
Cardiac arrhythmias Hypotension |
Bolus lasts 6-24 h Best in following level of consciousness Worse for cardiac disease |
| Fosphenytoin | 15-20 mg PE/kg 150 mg PE/min | Peak effect in 10 min (IV) Peak effect in 30min (IM) Elimination half-life 24-48 h |
Cardiac arrhythmias Hypotension |
Can be administered IM |
| Phenobarbital | 10-20 mg/kg<100 mg/min Maintenance level >40 µg/mL |
Effect in 5-20 min Peak in 1 h Elimination half-life 120 h |
Respiratory depression, hypotension (possible synergy with benzodiazepines) | Slower than benzodiazepines Depression of consciousness can be prolonged after loading |
| Valproic acid | 25 mg/kg or higher, up to 100 mg/min Maintenance level >100 µg/mL |
Peak effect in 15 min Elimination half-life 24 h |
Multiple interactions with other anticonvulsants (phenytoin, phenobarbital, lamotrigine) | No respiratory depression, arrhythmia or cardiac depression |
| Diazepam | 10 mg (0.25 mg/kg) Repeat q15 min;up to ? 40 mg<5 mg/min |
Effect in 1-2 min Peak in 20-30 min Metabolite half-life 36 h |
Sedation, respiratory depression, hypotension Recurrent symptoms as it wears off |
Very rapid interruption of convulsions Needs to be followed by maintenance anti-convulsants |
| Lorazepam | 4-8 mg (0.1-0.2 mg/kg)<2 mg/min | Effect in 2-5 minPeak in 15-30 min Elimination half-life 12-15 h |
Same as diazepam; less sudden | More prolonged protection (up to 12 h) against seizure recurrence No active toxic metabolites |
| Pentobarbital | Load 3-5 mg/kg Maintenance. 1-4 mg/kg/h |
Effect in minutes Elim-ination half-life 20-40 h |
Respiratory depression Hypotension Hypothermia |
Uniformly effective High mortality due to underlying disease Duration of treatment unknown (? 24-48 h) |
PE = phenytoin equivalent
Adapted from: Drislane FW. Status epilepticus. In: Schachter SC, Schomer DL, eds. The comprehensive evaluation and treatment of epilepsy. San Diego, CA: Academic Press; 1997. p. 149-172. With permission from Elsevier (www.elsevier.com).
Reviewed By:
Thaddeus Walczak MD
on:
Wednesday, December 31, 2003
