First10EM - November 16, 2015
..."Unlike simple seizures, which will generally resolve without any intervention and require clinical constraint to avoid overtreatment, status epilepticus (with generalized tonic clonic seizures) is a medical emergency that requires immediate management.
Notes
Although older definitions of status epilepticus focused on seizures lasting more than 30 minutes, a more practical definition is any individual seizure lasting more than 5 minutes or 2 seizures without full recovery of consciousness. From an emergency department standpoint, it a patient is still seizing by the time EMA arrives, it is status.
There are many theoretical reasons that one benzo might be chosen over another, but in head to head trials they have always come up identical. The only note I would make about specific agents is that diazepam seems to have a higher rate of recurrent seizures (up to 50% in the first 2 hours) if another antiepileptic is not given. If diazepam was successfully used to stop the seizure, I would probably start phenytoin..."
http://first10em.com/2015/11/16/status-epilepticus/