Formulary conversion from glipizide to glyburide: a cost-minimization analysis.

Economic pressure prompted us to search for and implement cost-saving strategies at Bronx Municipal Hospital. This paper describes a cost-minimization analysis of the impact of formulary substitution of glyburide for glipizide on glycemic control, safety, and costs. In 76 patients with computerized prescription records, switching from a mean daily glipizide dose of 19 mg to a mean daily glyburide dose of 10.2 mg did not affect glycemic control. A subset of 33 elderly patients experienced only three drug-related adverse events during the 2-year observation period. The conversion program yielded a 51% reduction in overall expenditures for oral hypoglycemic agents between 1991 and 1993. These findings indicate that our conversion program was successful, which has led to its becoming a model for other New York City municipal outpatient pharmacies.