Use of Proprietary Names by Prescribers for Discontinued Brand Drug Products With Existing Generic Equivalents

Purpose: To describe the endurance of continued use of proprietary names by prescribers for discontinued brand drug products with existing generic equivalents and to identify prescribing practice trends that can inform the formulation and evaluation of new proprietary names. Methods: A national outpatient prescription database, IMS's Vector One (R): National, was used to identify prescribing trends by examining drug use data for proprietary and generic names as they were written on actual prescriptions for 7 discontinued brand drug products from the years 2003 to 2010. Results: Drug use data from years 2003 to 2010 showed the endurance of continued use of proprietary names by prescribers for all 7 studied discontinued brand drug products. Overall, the number of prescriptions written in the proprietary name decreased over time but did not cease after brand drug product discontinuation. Of the 7 drugs studied, "Aldomet'' was the proprietary name with the longest continued use, such that approximately 8 out of 100 new prescriptions for methyldopa were still written in the proprietary name after 10 years of brand drug product discontinuation. Conclusions: This research identified that prescribers continued to prescribe by the proprietary names for many years after the discontinuation of brand drug products. This prescribing practice confirms the need to account for the proprietary names of discontinued brand drug products when formulating and evaluating new proprietary names.