Diastat® is simply diazepam formulated into a special water-soluble rectal gel and packaged by Valeant Pharmaceuticals in its own trademark, AcuDial, delivery system. Diazepam is commonly given intravenously for seizures and is thought to increase activity of gamma-aminobutyric acid (GABA), which is the primary inhibitory transmitter in the central nervous system.8 Diazepam is rapidly dispersed to the tissues, particularly the brain, and has half-life estimates that range from 20 up to 200 hours. Diastat® has the same types of contraindications, drug interactions and side effects as generic diazepam.
The primary advantage of rectal administration is that it is not necessary to gain intravenous access to introduce a therapeutic amount of diazepam into the system. Although the rate of absorption is slightly less than that of IV administration, rectal administration is very effective and faster than either intramuscular or oral routes. This slower absorption rate of rectally administered diazepam is advantageous, however, in that it decreases the risk of respiratory depression that is often associated with IV administration of benzodiazepines.9 This risk is enhanced with IV administration of diazepam due to a sudden spike in plasma concentrations of the drug.10 Rectal administration does not produce these rapid elevations and therefore does not carry a significant risk of respiratory depression.
Diastat® has proven to be extremely safe for the prehospital and non- medical settings. The manufacturers of Diastat® report that during initial trials, no events of respiratory depression occurred. These trials included patients who received as much as 180% of the recommended dose. Additionally, two of the patients in the study received “twice the target dose with no adverse effects reported.”11 In one specific case, 330% of the recommended dose was reported to have produced no signs of respiratory or cardiac depression.10 Moreover, an American Epilepsy Society 2000 abstract titled Respiratory Effects of Rectally Administered Diazepam (Diastat®) in Pediatric Epilepsy Patients: A Retrospective Study concluded: “The data show that Diastat® had little or no effect on respiration when administered to this population of pediatric epilepsy patients suffering from prolonged or cluster seizures. Results confirm the overall safety and efficacy of rectally administered diazepam in this treatment population.”12
Equally as impressive as its safety record is the documented efficacy of Diastat®. Clinical trials by the manufacturer indicate that 85% of the patients who received the preparation resolved their seizure activity without further intervention; 71% of these patients remained seizure free for 12 hours after resolution of the initial activity.11 A recent study of adult patients conducted by the University of Kentucky found that Diastat® stopped seizure activity in 90% of the patients who were enrolled.3 Overall, administration of rectal diazepam is considered to be a rapid and effective treatment for life-threatening seizure activity.
Currently, a number of states and local jurisdictions allow school nurses, as well as personal care assistants and other nonmedical paraprofessionals to administer prescribed Diastat® in the public school and daycare settings prior to arrival of EMS professionals. This accommodation did not come without controversy from both the school systems and other organizations. Ultimately, the courts have affirmed the individual's right to receive this life- saving intervention by applying case law as it relates to the Individuals with Disabilities Education Act (formerly the Education for All Handicapped Children Act of 1975), Title II of the Americans with Disabilities Act, and Section 504 of the Rehabilitation Act.13 In essence, the argument of schools and daycare systems was that they did not have qualified staff to administer such medications.13 The courts disagreed, indicating that Diastat® and other medications are a required accommodation for children needing such an intervention and thus must be provided in these educational environments. Overall, it has been determined that Diastat®, which was developed and approved by the FDA for safe administration outside a medical setting, is sufficiently safe to be administered by trained caregivers and paraprofessionals as part of each student's required emergency care plan in school.