Aim: Sulphonylureas are widely used in the management of type 2 diabetes. The effectiveness of treatment with oral antidiabetic drugs depends largely on patient compliance. The objective of the DIACOM (effect of DosIng frequency of oral Antidiabetic agents on the COMpliance and biochemical control of type 2 diabetes) study was to compare the compliance of patients treated with once-daily (od) or twice-daily (bid) sulphonylureas.
Methods: One hundred and five patients, previously treated with glibenclamide, were randomized to receive gliclazide in modified-release formulation (MR) once daily or glibenclamide twice daily for 16 weeks, using an electronic monitoring system (MEMS).
Results: A significant difference in compliance was observed between the two groups. The overall compliance was 93.5+/-14.0% in the once-daily gliclazide MR group and 87.2+/-21.1% in the twice-daily glibenclamide group (p<0.05), and the correct number of doses was taken on 86.3+/-15.4 and 66.9+/-29.0% of treatment days respectively (p<0.0001). The percentage of missed doses was 9.3+/-12.5% in the once-daily group and 17.5+/-18.0% in the twice-daily group (p<0.01). The percentage of doses taken in the correct time window and correct inter-dose interval was higher in the once-daily group, as was therapeutic coverage. Patients in the gliclazide MR group also achieved significantly better glycaemic control [fasting plasma glucose and glycated haemoglobin (HbA(1c))] than those treated with glibenclamide (p<0.0001).
Conclusions: The study demonstrates that patient compliance with once-daily gliclazide MR is significantly better than with twice-daily glibenclamide. Consistently better efficacy was observed for short-term (fasting glucose) and long-term glycaemic control (HbA(1c)) in the once-daily group. These results demonstrate the possible therapeutic advantages of once-daily agents over twice-daily agents in the treatment of type 2 diabetes.