Projected economic impact of clinical findings of generic entry of topiramate on G4 European countries

ABSTRACTObjectives: To explore the effects of generic substitution of the antiepileptic drug (AED) topiramate (Topamax in Canada; to convert observed Canadian costs into the settings of France, Germany, Italy, and the United Kingdom (UK); and to forecast the economic impact of generic topiramate entry in these four European countries. † Topamax is a registered trade name of Ortho-McNeil Neurologics, Inc., Titusville, NJ, USAResearch design and methods: Health claims from Regie de l'assurance maladie du Quebec (RAMQ) plan (1/2006–9/2008) and IMS Health data (1998–2008) were used. Patients with epilepsy and ≥2 topiramate dispensings were selected. An open-cohort design was used to classify observation into mutually-exclusive periods of branded versus generic use of topiramate. Canadian healthcare utilization and costs (2007 CAN$/person-year) were compared between periods using multivariate models. Annualized per-patient costs (2007€ or 2007£/person-year) were converted using Canadian utilization rates, Euro...