OBJECTIVE To compare the efficacy and safety of two daily doses of the new sulfonylurea, glimepiride (Amaryl), each as a once-daily dose or in two divided doses, in patients with NIDDM.

RESEARCH DESIGN AND METHODS Of the previously treated NIDDM patients, 416 entered this multicenter randomized double-blind placebo-controlled fixed-dose study. After a 3-week placebo washout, patients received a 14-week course of placebo or glimepiride 8 mg q.d., 4 mg b.i.d., 16 mg q.d., or 8 mg b.i.d.

RESULTS Fasting plasma glucose (FPG) and HbA^1c values were similar at baseline in all treatment groups. The placebo group's FPG value increased from 13.0 mmol/l at baseline to 14.5 mmol/l at the last evaluation endpoint (P ≤ 0.001). In contrast, FPG values in the four glimepiride groups decreased from a range of 12.4–12.9 mmol/l at baseline to a range of 8.6–9.8 mmol/l at endpoint (P ≤ 0.001, within-group change from baseline; P ≤ 0.001, between-group change [vs. placebo] from baseline). Two-hour postprandial plasma glucose (PPG) findings were consistent with FPG findings. In the placebo group, the HbA^1c value increased from 7.7% at baseline to 9.7% at endpoint (P ≤ 0.001), whereas HbA^1c values for the glimepiride groups were 7.9–8.1% at baseline and 7.4–7.6% at endpoint (P ≤ 0.001, within-group change from baseline; P ≤ 0.001, between-group change from baseline). There were no meaningful differences in glycemic variables between daily doses of 8 and 16 mg or between once- and twice-daily dosing. Adverse events and laboratory data demonstrate that glimepiride has a favorable safety profile.

CONCLUSIONS Glimepiride is an effective and well-tolerated oral glucose-lowering agent. The results of this study demonstrate maximum effectiveness can be achieved with 8 mg q.d. of glimepiride in NIDDM subjects.