Abstracts

Rationale: Epilepsy is a common comorbid disorder among children and adults with neurodevelopmental disorders and significant intellectual disabilities (ID). Seizure management in this population can be complex due to the multifaceted nature of underlying neurological conditions and differences in response to anti-epileptic drugs (AEDs). The selection of AEDs in adults with ID is often trial and error due to the lack of research in this area and the heterogeneity of this population. The purpose of the present study was to evaluate differences in seizure rate and specific anticonvulsant medication related side effects when adult patients with epilepsy secondary to neurodevelopmental disorders were switched from Depakote (DVPX) to Depakote-ER (DVPX-ER). Methods: 31 Patients with epilepsy secondary to neurodevelopmental disorders who received treatment for a minimum of 1 year and who were switched from the delayed release formulation of DVPX to the extended release formulation of DVPX were studied. Data were collected from the three quarters prior to the switch and the 3 quarters following the switch to DVPX-ER. The quarter in which the switch took place was skipped to allow sufficient time for dosing titration and to achieve therapeutic DVPX-ER levels. Outcome measures included seizure data (type, rate, duration), co-prescribed anti-epileptic medications, medication side effects exam and ratings, and lab tests. Results: All patients were able to be successfully switched from DVPX to DVPX-ER over the course of a quarter with the majority of patients experiencing at least equivalent coverage of seizures. As a group this patient sample demonstrated a significant reduction in average seizure rate (28% decrease) and average number of cluster seizures (37% decrease) following the switch to DVPX-ER. Two of the 31 (6%) patients demonstrated a significant increase in seizure rate and 8 of the 31 (26%) demonstrated a significant reduction in seizure rate following the switch to DVPX-ER. Side effects monitoring data revealed a significant increase in average ratings of edema associated with DVPX-ER treatment with no changes observed for average ratings of nausea / vomiting. Conclusions: Depakote-ER appears to be an effective option for seizure management in adult patients with ID and complicated seizure disorders secondary to neurodevelopmental disorders. Individual differences in the magnitude of response to DVPX-ER were evident in this sample indicating that careful individualized monitoring of anticonvulsant cross-titration is necessary in this patient group. The unique pharmacokinetic properties of DVPX-ER may allow for a simplified administration schedule and improved compliance among adults with ID who respond positively to a switch to Depakote – ER.