Pioglitazone/metformin.

A fixed-dose pioglitazone/metformin tablet is approved in the US and the EU for the treatment of adult patients with type 2 diabetes mellitus who currently have inadequate glycaemic control with metformin monotherapy. In the US, the combination tablet is also approved for the treatment of adult patients with type 2 diabetes who currently have inadequate glycaemic control with pioglitazone monotherapy and for those already receiving a combination of pioglitazone and metformin. Bioequivalence, based on absorption and bioavailability parameters, has been established between the fixed-dose tablets and equivalent doses of pioglitazone and metformin coadministered as separate agents. Combination therapy with pioglitazone plus metformin was significantly more effective at improving both glycaemic and lipid control than metformin plus placebo in patients with type 2 diabetes in a 16-week, well designed trial. Pioglitazone plus metformin demonstrated similar antihyperglycaemic efficacy to that of rosiglitazone plus metformin in a well designed 12-month trial; however, pioglitazone plus metformin was the superior combination in terms of lipid control. In several comparative trials of 1-3.5 years' duration, pioglitazone plus metformin was at least as effective as combination therapy with a sulphonylurea plus metformin in terms of antihyperglycaemic efficacy, but provided superior lipidaemic control with regard to levels of triglyceride and high-density lipoprotein-cholesterol. Pioglitazone plus metformin was generally well tolerated in patients with type 2 diabetes, with adverse events common to metformin monotherapy observed at a similar incidence to that with metformin plus placebo.