Diabetes control in the elderly: A randomized, comparative study of glyburide versus glipizide in non-insulin-dependent diabetes mellitus

This study sought to compare the efficacy and safety of glyburide and glipizide in elderly patients with well-controlled non-insulin-dependent diabetes mellitus (NIDDM). One hundred forty-five patients aged ≥65 years with NIDDM that was controlled for at least 3 months with oral sulfonylurea therapy were enrolled. After a washout phase, 139 patients were randomized to receive glyburide, 1.25 or 2.5 mg/day, or glipizide, 2.5 or 5 mg/day. During a 4- to 8-week titration phase, doses were adjusted according to prescribing guidelines. Patients who achieved glycemic control (fasting plasma glucose of ≤8.9 mmol/L, or 160 mg/dl, on two consecutive occasions) entered a maintenance phase, for a total treatment period of 4 months. Hypoglycemia was defined as a fasting plasma glucose of <3.3 mmol/L (60 mg/dl) or a random plasma glucose of <2.8 mmol/L (50 mg/dl), with associated signs and symptoms. Most patients in both the glyburide and glipizide groups achieved satisfactory glycemic control; there were no significant differences between groups in fasting plasma glucose or hemoglobin A(1c) levels at any time. Of note, the mean dose of glyburide (8.5 mg/day) was approximately half that of glipizide (15.4 mg/day) at the end of the maintenance period (P=0.009). Both regimens were well tolerated and were associated with a similarly low incidence of hypoglycemia. It was concluded that both glyburide and glipizide are suitable for the treatment of NIDDM in properly selected elderly patients.