Safety of Diastat, a rectal gel formulation of diazepam for acute seizure treatment

Abstract

Diazepam rectal gel (Diastat) is the only medication approved by the US FDA for the management of selected, refractory patients with epilepsy, on stable regimens of antiepilepsy drugs, who require intermittent use of diazepam to control bouts of increased seizure activity. An analysis of the safety of diazepam rectal gel reveals that this formulation has certain advantages over intravenous diazepam administration: most notably a very low incidence of respiratory depression, low potential for abuse and the opportunity for out-of-hospital use by non-professional caregivers. Sedation is the most common adverse effect of rectal diazepam treatment, occurring in approximately one-quarter of patients, although drug-induced somnolence is difficult to distinguish from normal post-ictal sedation. Overdosage of diazepam rectal gel is rarely associated with serious clinical consequences, and overdoses of up to 330% of the maximum recommended dosage have been reported without any respiratory or cardiac depression. Under-administration may be a serious safety issue because of morbidity that may result if seizures are not terminated. Chronic administration may cause tachyphylaxis and should be avoided.