The study recruited patients with Type II Diabetes with elevated HbA1c and fasting plasma glucose (FPG). Approximately 50% of the patients were treatment naive, 25% had been on metformin monotherapy, 15% on sulphonylurea monotherapy and 10% on a combination of metformin and sulphonylurea. Patients were randomised to one of four treatment options as follows:
- Metformin SR 1500mg once daily
- Metformin SR 1500mg twice daily
- Metformin SR 2000mg once daily
- Metformin IR 1500mg twice daily
Comparable reductions were seen in HbA1c and FPG in all groups and the rate of adverse gastrointestinal events was also similar in all groups. There was more nausea reported in the IR metformin group however discontinuation rates were not statistically different between the groups.
The product used in this study is not available in the UK however there is a sustained release version of metformin (Glucophage SR)® that also failed to demonstrate superior tolerability in a randomised controlled trial. As reported earlier, the Scottish Medicines Consortium rejected Glucophage SR for use on the NHS in Scotland.
Action: IR Metformin remains the first line treatment choice in patients with Type II Diabetes. SR Metformin fails to offer any advantages over IR Metformin.