The collective clinical data support the concept that lorazepam is highly effective for a broad range of seizure types, with the major inadequacy being in myoclonus, a seizure type typically highly resistant to other anticonvulsants as well. In addition to its effectiveness, lorazepam appears to have two other major advantages; a prolonged duration of action, which makes frequent or continuous administration unnecessary, and a high degree of freedom from serious side effects involving either the respiratory or cardiovascular system. Although experience at this time is insufficient to allow a firm statement concerning effective concentrations, such concentrations appear readily achievable in most patients with injections of 4 to 5 mg. Lorazepam appears to meet all the requirements of an anticonvulsant useful for treatment of status epilepticus and should prove to be a major drug in the treatment of this condition.