Comparison of Adherence to Glimepiride/Metformin Sustained Release Once-daily Versus Glimepiride/Metformin Immediate Release BID Fixed-combination Therapy Using the Medication Event Monitoring System in Patients With Type 2 Diabetes.

Purpose: The purpose of this study was to compare the adherence of the glimepiride/metformin sustained release (GM-SR) once-daily fixed-dose combination and glimepiride/metformin immediate release (GM-IR) BID fixed-dose combination in type 2 diabetes therapies.

Methods: An open-label, randomized, multicenter, parallel-group study was conducted at 11 hospitals in the Republic of Korea. A total of 168 patients with type 2 diabetes treated with >4 mg of glimepiride and 1000 mg of metformin by using free or fixed-dose combination therapy for at least 2 weeks were enrolled. Patients were randomized to receive GM-SR 4/1000 mg once-daily or GM-IR 2/500 mg BID for 24 weeks. Adherence was compared by using the Medication Event Monitoring System (MEMS).

Findings: A significant difference in adherence was observed between the 2 groups. Overall adherence, defined by the number of container openings divided by the number of prescribed doses, was 91.7% in the GM-SR group and 88.6% in the GM-IR group (P < 0.001). The percentage of treatment days with the correct number of doses taken was 85.3% in the GM-SR group and 75.1% in the GM-IR group (P < 0.001). The percentage of missed doses was 11.7% in the GM-SR group and 15.3% in the GM-IR group (P < 0.001). The percentage of doses taken in the correct time window and therapeutic coverage were higher in the GM-SR group (P < 0.001). There was no significant difference in glycosylated hemoglobin changes or number of adverse events between the 2 groups. A total of 168 patients randomized to receive GM-SR once daily (86 patients) or GM-IR twice daily (82 patients). Mean Age were 57.8 ± 9.6 years old. Male : female ratio was 47.6 : 52.4 %. Body mass index were 66.3 ± 12.0 kg/m2, Diabetes duration were 10.5 ± 6.6 years.

Implications: This study showed that patient adherence with GM-SR once daily was significantly better than with GM-IR BID. ClinicalTrials.gov identifier: NCT01620489.