Three Part Question
In [an adult epileptic patient suffering a grand mal fit] is [intravenous lorazepam safer and more effective than intravenous diazepam] at [safely terminating the convulsions]?
Clinical Scenario
A 45 year old female epileptic presents after sustaining a grand mal convulsion at home. She starts fitting again on arrival in the emergency department; the fit does not stop spontaneously after 5 minutes. The paramedics have secured intravenous access prior to arrival but have not given any anti-convulsants. You wonder whether lorazepam is more effective than diazepam as a first choice drug to safely terminate this convulsion.
Search Strategy
Medline 1966-09/00 using the OVID interface.
[(exp epilepsy OR exp epilepsy, generalised OR exp epilepsy, tonic-clonic or epilepsy.mp OR fits.mp OR exp convulsions OR convulsion$.mp OR exp seizures OR exp alcohol withdrawal seizures OR seizure$.mp) AND (exp lorazepam OR lorazepam$.mp)] LIMIT to human AND english
Search Outcome
133 papers found of which 131 papers were irrelevant or of insufficient quality. The remaining 2 papers are shown in the table.
Relevant Paper(s)
Author, date and country |
Patient group |
Study type (level of evidence) |
Outcomes |
Key results |
Study Weaknesses |
Leppik IE et al 1983 USA | 78 adult patients with status epilepticus
IV Lorazepam (4mg) vs IV Diazepam (10mg) | PRCT | Clinical control of seizure activity: | Lorazepam 89% within 2 doses vs Diazepam 76% within 2 doses | Small numbers
Many different types of seizure activity |
Treiman DM et al 1998 USA | 384 patients with generalised convulsions from 570 patients with status epilepticus
IV diazepam (0.15mg/kg) plus phenytoin (0.1mg/kg) vs IV lorazepam (0.1mg/kg) vs IV phenobarbitone (15mg/kg) vs IV phenytoin (18mg/kg) | PRCT | Stopping of all motor seizure activity/EEG activity in <20 minutes | 55.8% vs 64.9% vs 58.2% vs 43.6%. In an intention to treat analysis the differences between treatment groups were not significant (p=0.12) | Some patients were treated prior to inclusion in trial
No long term follow-up of patients |
Comment(s)
The incidence of status epilepticus is given as 15-30 per 100,000 per year. It carries a considerable mortality (approximately 10%). The best first line treatment remains controversial. The use of diazepam is limited by its rapid redistribution out of the CNS. The duration of action of diazepam is approximately 20-30 minutes. Pharmcokinetic studies of lorazepam have shown it has an elimination half-life of 13 hours. Lorazepam has a much longer duration of anti-convulsant action than diazepam and has an equivalent onset of action. Studies in healthy voluteers suggest it has reduced cardio-respiratory side-effects compared to other benzodiazepines. There may be an increased risk of thrombophlebitis when compared to IV Diazemuls.
Clinical Bottom Line
Intravenous lorazepam is effective and safe in the treatment of status epilepticus. It should be the first line of treatment.
References
- Leppik IE, Derivan AT, Homan RW et al. Double-blind study of lorazepam and diazepam in status epilepticus. JAMA 1983;249:1452-4.
- Treiman DM, Meyers PD, Walton NY et al. A comparison of four treatments for generalized convulsive status epilepticus. N Eng J Med 1998;339:792-8.