Abstract
Some patients with epilepsy continue to have seizures despite daily treatment with antiseizure medications. This includes seizure clusters (also known as acute repetitive seizures), which are an increase in seizure frequency that is different from the usual seizure pattern for that patient. In the literature, the term "rescue" is used for pharmacologic treatment for seizure clusters, but clarity regarding timing or whether a caregiver or patient should wait until a moment of life-threatening urgency before administering the medication is lacking. Additionally, the concept of waiting 5 minutes to identify and initiate treatment of status epilepticus has been carried over to the treatment of seizure clusters, as well as the idea of waiting owing to safety concerns, without reevaluation in the context of the reported safety profiles for currently available as-needed therapies when administered as prescribed. Delaying treatment of seizure clusters may have negative outcomes, including injury, emergency room use, hospitalization, and progression to status epilepticus. Additionally, increased time for administration of benzodiazepines, the cornerstone therapies for seizure clusters, may lower the potency and effectiveness once administration takes place, because of physiologic changes. Thus, clarifying the importance of timing in the treatment terminology may be of benefit in the acute context. The term "immediate-use seizure medication" (ISM), meaning treatment that is administered as quickly as possible once a seizure cluster is recognized, may help to clarify the timing of as-needed treatment. This review examines the recognition and definitions of seizure clusters, the physiologic rationale for ISM for seizure clusters, and the effectiveness and safety of early treatment. Remaining knowledge gaps are also discussed. The findings of this review suggest that it may be time to revisit the terminology of "rescue", which implies waiting to administer treatment for seizure clusters, as doing so is not supported by pathophysiologic, effectiveness, or safety data.