Abstracts

Rationale: Although intrarectal diazepam (IRD) is widely used for treatment of seizure clusters, intravenous levetiracetam (IVL), even though unapproved, is attractive in this setting because of its ease of administration and lack of interaction with other drugs. This retrospective study evaluated the efficacy of combined IRD and IVL (COM) intervention compared to either agent alone in the treatment of prolonged seizures in institutionalized, mentally retarded patients. Methods: Our institution’s protocol defines prolonged seizure as seizure activity (single or serial seizure/s of any type) lasting >3 min, and recommends intervention consisting of administration of IRD on the floor, transfer to a unit providing 24-hour nursing supervision within the facility, establishment of immediate IV access followed by infusion of IVL over 15 min, and transfer to the nearest emergency room (ER) if the seizures could not be controlled at the end of IVL infusion. Based on the physician’s assessment, two exceptions are possible: 1) direct transfer to the ER when IV access is not feasible and seizures persist for 10 min after IRD; 2) direct administration of IVL (without prior IRD) for patients with established IV access who are already under continuous supervision for other reasons. Thus, the interventions for prolonged seizures could be assigned into 3 arms: COM (IRD followed by IVL), IRD only, IVL only. We retrospectively identified and included all the interventions for prolonged seizures over a 14-month period. We excluded those interventions in which patients were directly transferred to the ER without receiving either drug in the facility. Outcome measures were the escape criteria defined as recurrent seizure activity within 4 hours of the intervention (primary) and transfer to the ER for uncontrolled or recurrent seizures (secondary). Results: There were 64 interventions in 18 patients: 22 COM (11 patients), 18 IRD (10 patients), 24 IVL (8 patients). The patients in the three arms were not mutually exclusive. All the patients were classified as having symptomatic generalized epilepsy with multiple seizure types. The patient characteristics are summarized in the Table. Seizure recurrence within 4 hours occurred in 1/22 (5%) of COM, 7/18 (39%) of IRD and 8/24 (33%) of IVL interventions. ER transfers occurred once (5%) in COM, four times (22%) in IRD and none in IVL arms. Among the 13 patients who received IVL in the two arms, 12 were already on maintenance levetiracetam. There were no serious adverse effects directly related to the administration of IRD or IVL. Conclusions: The results of this preliminary study suggest that the combined intervention with IRD and IVL is feasible and well tolerated in institutionalized patients, and appears to be more efficacious in controlling seizures and preventing recurrence compared to either drug alone for the treatment of prolonged seizure activity. Prospective, randomized interventions are needed to confirm these findings.