Pharmacokinetics and pharmacodynamics of glyburide/metformin tablets (Glucovance) versus equivalent doses of glyburide and metformin in patients with type 2 diabetes.

Author(s): Donahue SR, Turner KC, Patel S

Affiliation(s): Department of Clinical Discovery, Bristol-Myers Squibb Pharmaceutical Research Institute, Princeton, NJ 08543, USA. stephen.donahue@bms.com

Publication date & source: 2002, Clin Pharmacokinet., 41(15):1301-9.

Publication type: Clinical Trial; Randomized Controlled Trial

OBJECTIVE: To compare the effects of two different formulations of glibenclamide (glyburide) combined with metformin on postprandial glucose excursions, and to assess their pharmacokinetics. The formulations were a combination glibenclamide/metformin tablet (Glucovance; controlled-particle-size glibenclamide and metformin) versus glibenclamide (Micronase) and metformin (Glucophage) coadministered separately. DESIGN: A randomised, double-blind, two-way crossover study in which patients with type 2 diabetes received either glibenclamide/metformin 2.5/500mg tablets or glibenclamide 2.5mg with metformin 500mg twice daily for 14 days. After a 2-week washout, patients were crossed over to the other treatment for 14 days. Patients consumed standardised meals on the days when pharmacokinetic and pharmacodynamic evaluations were performed. PARTICIPANTS: Forty patients with type 2 diabetes were enrolled; 37 were randomised (18 men, 19 women) and 35 completed the study. Mean age was 58 years; mean body mass index was 31 kg/m(2). The baseline glycated haemoglobin (HbA(1c)) was 9.3% for both treatment groups. MAIN OUTCOME MEASURE: Two-hour postprandial glucose excursion (PPGE) was used to assess postprandial glucose dynamics. RESULTS: Treatment with glibenclamide/metformin resulted in a significantly smaller mean PPGE than was attained by treatment with glibenclamide plus metformin, according to measurements taken after the day 14 afternoon standardised meal (89.5 vs 117.4 mg/dl, p = 0.011). The mean glibenclamide peak concentration (C(max)) was significantly greater (approximately 16%) after glibenclamide/metformin treatment on both days 1 and 14. Glibenclamide/metformin treatment was associated with a 2-fold greater area under the concentration-time curve to 3 hours for glibenclamide (AUC(3)) [p < 0.001], although the AUC over the administration interval was equivalent for both formulations. CONCLUSION: In patients with type 2 diabetes, glibenclamide/metformin resulted in lower PPGE, suggesting that the higher glibenclamide AUC(3) observed with this formulation may contribute to better postprandial glycaemic control than is attained by glibenclamide plus metformin separately.