Lorazepam (Ativan) has several advantages:

• It acts rapidly enough to interrupt seizures quickly.
• It also has a more prolonged anticonvulsant effect. (Some physicians consider it to satisfy the requirements for both the acute interruption of SE and prolonged protection against recurrence.)
• Compared to diazepam, doses are approximately half as large and it is half as lipid-soluble. Its brain penetration is slower but still rapid.
• Its effect declines less rapidly than diazepam.
• It has no active, troublesome metabolites.

Many epileptologists prefer lorazepam because of its favorable pharmacokinetics, but direct comparative studies are few. A double-blind, randomized trial found lorazepam marginally more effective than diazepam in controlling SE, with an onset of action not significantly different. Adverse effects are similar to those of diazepam, although perhaps less sudden. Lorazepam may provide 12 hours of anticonvulsant effect, but acute tolerance may reduce its maintenance value.

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 and revised February 2004 by Thaddeus Walczak, MD, MINCEP® Epilepsy Care, Minneapolis, MN