Metformin remains the first-line drug of choice in type 2 diabetes mellitus.

• metformin should be titrated up slowly to minimise the possibility of gastrointestinal upset
• if standard-release metformin is not tolerated then modified-release metformin should be trialled

It's worthwhile thinking of the average patient who is taking metformin for T2DM, you can titrate up metformin and encourage lifestyle changes to aim for a HbA1c of 48 mmol/mol (6.5%), but should only add a second drug if the HbA1c rises to 58 mmol/mol (7.5%)