Abstracts

Rationale: There is a bimodal distribution in the incidence of new onset seizures with one peak occurring in the very young and the second peak occurring in the elderly. The treatment of epilepsy in the elderly may be complicated by pharmacokinetic and pharmacodynamic changes occurring during the aging process. Three Veterans Cooperative trials evaluating antiepileptic drug (AED) therapy in the elderly demonstrated that the ability to tolerate the AED is a more determining factor for long term success than the ability to suppress seizure activity. In general, elderly patients appear more sensitive to medication side effects. This may stem from co-morbid conditions, concurrent medications, pharmacokinetic changes, and/or pharmacodynamic changes. Therefore, it is important to study the efficacy and tolerability of AEDs in the elderly. Valproic acid has been available for the treatment of partial and generalized seizures since 1978. Depakote and Depakote-ER are among the dosage forms of divalproex sodium. Depakote is administered twice a day. Depakote-ER is a controlled release drug delivery system designed to release drug over a 22 hour period which allows for once a day dosing. This study will address the efficacy and tolerability of Depakote-ER in elderly patients with epilepsy.Methods: This is a single center, open-label, study conducted in patients age 60 and older with a confirmed diagnosis of epilepsy. Fourteen patients with newly diagnosed partial seizures, patients with uncontrolled partial seizures requiring medication adjustment, or patients with partial seizures who would benefit from once a day dosing were enrolled. All the patients were initially on Depakote and were switched to the Depakote-ER formulation. In the conversion from Depakote to Depakote-ER the dosage was increased from 10 to 20 %. Each patient underwent a complete laboratory analysis and completed a Seizure Severity Questionnaire (SSQ), Beck’s Depression Inventory (BDI), QOLIE-31-P, seizure count diary and the Adverse Events Profile (AEP).Results: The primary objective of this study was to assess the effectiveness, (i.e. the efficacy and tolerability), of Depakote-ER in elderly patients with epilepsy. Effectiveness, as measured by survival in the study, was 100%. There was no significant change in the Seizure Severity Questionnaire (SSQ) score and no significant change from baseline of seizure frequency as determined by seizure counts, except in one patient who failed to increase the dose when converting to Depakote-ER. All of the patients preferred the once a day dosing and compliance was improved. Reported side effects were less with the ER formulation. There was no significant change in laboratory parameters in this series.Conclusions: Conversion from Depakote to Depakote-ER is well tolerated in patients 60 and older. Once a day dosing was preferred by the patients and seizure frequency was unchanged when the conversion guidelines were followed. Investigator initiated study supported by funding from Abbott.