Outcomes associated with switching from monotherapy to adjunctive therapy for patients with partial onset seizures

Background: Some patients with partial onset seizures are drug-resistant and may benefit from adjunctive therapy. This study evaluated monotherapy/sequential monotherapy versus adjunctive therapy on use/costs. Methods: Retrospective analysis using commercial/Medicare database (1 January 2007 to 31 December 2009). Patients with >= 2 diagnoses for partial onset seizures who received >= 2 prescriptions of the same antiepileptic drug were included. Outcomes assessed in the 12-month follow-up period were hospitalizations, ER visits, outpatient visits and prescription costs for patients who received monotherapy but switched to adjunctive. Results: 1353 patients met criteria. After patients transitioned to adjunctive therapy, the average monthly percentage of patients with a hospitalization decreased from 5.3 to 3.0% (p < 0.0001). Similar results occurred with epilepsy-related hospitalizations (4.0 vs 1.7%, p < 0.0001). Adjusted costs decreased significantly (US$ 4205 vs 2944/month, p < 0.0001). Adjusted epilepsy-related costs decreased from US$ 1601 to 909/month (p < 0.0001). Conclusion: Adjunctive therapy in potentially drug-resistant patients with partial onset seizures can lead to reduced healthcare use and costs.