- Male subjects who had a serum creatinine level greater than or equal to 2.0 mg/dL (greater than or equal to 177 µmol/L) (greater than or equal to 1.5 mg/dL; [greater than or equal to 133 µmol /L] if taking metformin) and female subjects who have serum creatinine greater than or equal to 1.8 mg/dL [greater than or equal to 159 µmol /L] (greater than or equal to 1.4 mg/dL [greater than or equal to 124 µmol /L] if taking metformin).