Adherence to a fixed-dose combination of rosiglitazone/glimepiride in subjects switching from monotherapy or dual therapy with a thiazolidinedione and/or a sulfonylurea

Ann Pharmacother. 2010 May;44(5):791-9. doi: 10.1345/aph.1M426. Epub 2010 Apr 6.


Background: In 2005, a fixed-dose combination therapy (FDCT) of rosiglitazone maleate and glimepiride became available for treatment of type 2 diabetes mellitus. It is hypothesized that FDCTs increase adherence by decreasing the number of required tablets.

Objective: To assess changes in medication adherence and hemoglobin A(1c) (A1C) values in subjects switching from monotherapy with either a sulfonylurea or rosiglitazone or dual therapy with both to rosiglitazone/glimepiride FDCT.

Methods: This retrospective database analysis included subjects with 1 or more prescription fills for rosiglitazone, a sulfonylurea, or rosiglitazone/glimepiride FDCT during the identification period of January 1, 2006, to September 30, 2006. Subjects were grouped according to baseline and follow-up period treatment regimens: sulfonylurea or rosiglitazone monotherapy switched to sulfonylurea and rosiglitazone dual therapy (Mono/Dual), monotherapy to rosiglitazone/glimepiride FDCT (Mono/FDCT), sulfonylurea and rosiglitazone dual therapy in both periods (Dual/Dual), and dual therapy to rosiglitazone/glimepiride FDCT (Dual/FDCT). The medication possession ratio (MPR) was calculated as a measure of adherence. The change in A1C from the baseline period to the follow-up period was assessed for each cohort.

Results: The study included 16,490 subjects. From baseline to follow-up, MPR decreased for both the Mono/FDCT cohort and the Mono/Dual cohort, but the magnitude of this decrease was less for the Mono/FDCT cohort (-0.02 vs -0.10; p < 0.001). Mean MPR significantly improved for the Dual/FDCT cohort compared with the Dual/Dual cohort (+0.10 vs +0.05; p < 0.001). The mean absolute A1C reduction did not differ significantly between the Mono/FDCT cohort (-1.08%) and the Mono/Dual cohort (-0.77%). Compared with the Dual/Dual cohort, the Dual/FDCT cohort experienced a greater absolute reduction in A1C (-0.06% vs -0.51%; p = 0.004). The results remained statistically significant in the multivariate model.

Conclusions: Switching to rosiglitazone/glimepiride FDCT, in comparison with switching to dual therapy, was associated with improvements in medication adherence and glycemic control.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cohort Studies
  • Databases, Factual
  • Diabetes Mellitus, Type 2 / drug therapy*
  • Drug Combinations
  • Drug Therapy, Combination
  • Drug Utilization / statistics & numerical data
  • Humans
  • Hypoglycemic Agents / administration & dosage
  • Hypoglycemic Agents / therapeutic use*
  • Patient Compliance*
  • Retrospective Studies
  • Rosiglitazone
  • Sulfonylurea Compounds / administration & dosage
  • Sulfonylurea Compounds / therapeutic use*
  • Thiazolidinediones / administration & dosage
  • Thiazolidinediones / therapeutic use*
  • Treatment Outcome


  • Drug Combinations
  • Hypoglycemic Agents
  • Sulfonylurea Compounds
  • Thiazolidinediones
  • Rosiglitazone
  • glimepiride
  • 2,4-thiazolidinedione