Aim: To evaluate the efficacy and incidence of hypoglycaemic symptoms associated with fixed combinations of metformin and glibenclamide (glyburide in the USA) formulated within a single tablet (tablet strengths 250 mg/1.25 mg, 500 mg/2.5 mg and 500 mg/5 mg), in comparison with metformin 500 mg and glibenclamide 2.5-5 mg monotherapy, in clinically important patient subgroups within the type 2 diabetic population.
Methods: A total of 1856 patients from three randomized, double-blind, multicentre, parallel-group clinical trials were stratified at baseline according to HbA1C (< 8% or > or = 8%), age (< 65 years or > or = 65 years) and body mass index (BMI; < 28 kg/m2 or > or = 28 kg/m2). The effects of study treatments on HbA1C and the incidence of hypoglycaemic symptoms were determined in each subgroup.
Results: The combination treatments were more effective than either monotherapy irrespective of baseline HbA1C, age or BMI in each trial. Antihyperglycaemic effects were greater in patients with HbA1C > or = 8% at baseline, especially with the combinations. The majority of hypoglycaemic symptoms with glibenclamide-containing treatments occurred in patients with HbA1C < 8% at baseline. Neither age nor BMI had a marked effect on the efficacy of the combination treatments, and there was no increase in hypoglycaemic symptoms in older patients.
Conclusions: Single-tablet metformin-glibenclamide combination treatment is more effective than metformin or glibenclamide monotherapy, and is well tolerated in patients with hyperglycaemia inadequately controlled by diet and exercise or antidiabetic monotherapy, irrespective of their severity of hyperglycaemia at baseline, age or weight.