GlaxoSmithKline has launched what it says is the first fixed-dose combination product based on a glitazone and a sulfonylurea - two commonly-used oral diabetes medications - in the USA.

Avandaryl is based on GSK’s Avandia (rosiglitazone maleate) and the active ingredient in Sanofi-Aventis’ Amaryl (glimepiride), now generically available in the USA. GSK already sells a combination of rosiglitazone and another diabetes drug, metformin, as Avandamet.

Combined sales of Avandia and Avandamet advanced 22% to £355 million ($630m) in the third quarter of 2005, and the availability of Avandaryl is expected to add some additional momentum to the franchise, helping it top $2.8 billion in sales in 2006, according to analysts. The product is still under regulatory review in Europe.

Avandaryl has been approved for use in patients with type 2 diabetes who are already treated with a combination of rosiglitazone and sulfonylurea given as separate doses, as well as those on monotherapy with a sulfonylurea or rosiglitazone who need additional blood sugar control.

Almost two-thirds of type 2 diabetes patients fail to show good blood sugar control on their current treatment regimens, according to GSK, and this raises the risk that they will go on to develop diabetic complications such as nerve damage, cardiovascular disease and eye problems in later life.

Earlier this month, the US Food and Drug Administration changed the labelling for all of GSK’s rosiglitazone-containing products, including Avandaryl, to warn of a rare side effect called macular oedema in the eye. The European Medicines Agency had also drawn attention to this rare side effect in rosiglitazone and another drug in the same class, Takeda’s Actos (pioglitazone), and it is not expected to have a significant impact on sales of the drugs.