Children with seizures are frequently seen in the emergency department. The drug lorazepam, which is commonly used, is not labeled by the US Food and Drug Administration for children for this use. The FDA, under the Best Pharmaceuticals for Children Act, has requested that a study comparing diazepam, a drug that is labeled by the FDA for this indication, with lorazepam be performed. The study will show whether one drug is more effective and safe than the other.

Textbooks and expert opinion recommend both diazepam and lorazepam as initial therapy for children in status epilepticus (SE) and provide recommended doses that are commonly used. However, unlike diazepam, lorazepam is only FDA-approved for treatment for SE in patients over 18 years of age. Despite this fact, many experts support the use of lorazepam over diazepam in pediatric SE. Increased duration of action, increased effectiveness in terminating SE, and a lower incidence of respiratory depression have been cited as potential advantages of lorazepam over diazepam. However, data to support firm recommendations for one medication over another are lacking. Thus, either diazepam (FDA-approved) or lorazepam can be considered first-line agents for pediatric SE, and the physician's choice of agent depends on local practice patterns and individual treatment styles. In the prehospital (Emergency Medical Services) setting, diazepam is commonly chosen because of a longer shelf life without refrigeration.

The purpose of this study is to determine the differences in efficacy and safety between these two commonly used benzodiazepines, as requested by the FDA under the Best Pharmaceuticals for Children Act, using the Exception from Informed Consent provided by the FDA.

Inclusion Criteria:

1. Age 3 months to less than 18 years;

2. Generalized tonic clonic status epilepticus, defined as:

   1. Three or more generalized tonic clonic seizures within the last hour and currently experiencing a convulsion (i.e. the current convulsion may be the third convulsion within one hour); or
   2. Two or more generalized tonic clonic seizures in succession with no recovery of consciousness between seizures and currently experiencing a convulsion (i.e. the current convulsion may be the second convulsion without recovery of consciousness after the first convulsion); or
   3. A seizure that lasts at least 5 minutes that is either generalized tonic clonic in its entirety or starts focal and then generalizes. The seizure must be associated with loss of consciousness

Exclusion Criteria:

1. Pregnancy;
2. Shock prior to study drug (sustained hypotension requiring inotropic therapy);
3. Significant dysrhythmia prior to study drug (other than sinus tachycardia);
4. Need for emergent surgical intervention and general anesthesia for a condition present prior to study drug;
5. Known sensitivity to benzodiazepines or known contraindication to benzodiazepine use; or
6. Use of a benzodiazepine within 1 week of presentation.

Certain exclusion criteria may not be known at the time of drug administration due to the need for emergent treatment. Thus patients will be terminated from the study (early terminators) if the investigators discover any of the following conditions after administration of study drug:

1. Pregnancy;
2. Use of a benzodiazepine within 1 week of presentation.
3. Parent/guardian refusal to give informed consent by the methods described;
4. Patient's refusal to assent (for patients ≥ 7 yrs old and mentally competent to understand study procedures) by the methods described, or as required by the local IRB;