Conversion from glipizide to glyburide: long-term follow-up of a cost-impact survey focusing on the elderly.

The appropriate use of second-generation oral hypoglycemic agents is limited by the lack of definitive guidelines for their use in elderly diabetic patients and controversy over relative dosing equivalence. We previously conducted a survey to determine the feasibility and cost of converting diabetic patients from glipizide to glyburide. This new survey provides an extended, 24-month follow-up in 210 patients and focuses on findings in elderly patients. The mean final daily dose of glyburide (11.6 mg) was lower than the preconversion dose of glipizide (18.7 mg) (P < or = 0.0001). One hundred forty-one (67%) patients successfully continued glyburide for 24 months, including 103 (73%) patients who were 65 years of age or older. There was no apparent correlation between age and final dose of glyburide, ability to continue glyburide, or risk of stopping glyburide. The conversion program reduced the mean daily dose after switching from glipizide to glyburide, which was preserved throughout the observation period. The program also conferred a 49% savings in the projected 2-year expenditures for second-generation oral hypoglycemic agents.