Avandia, a drug for treating diabetes type 2, encourages the body to reabsorb bone, making them weaker and more likely to break, say experts. Avandia, a top selling drug, is made and marketed by GSK (GlaxoSmithKline).

Studies had previously indicated that Avandia raised the risk of developing bone fractures among women. A new report, published in Nature, confirms this, it also explains why this is so. The drug, say scientists, boosts the action of osteoclasts, cells that weaken bones.

According to team leader, Professor Ronald Evans, the Salk Institute for Biological Studies, La Jolla, California, there is a delicate balance between the deposition of new bone and the removal of old bone. Every bit of bone that is taken away should be counteracted by the same amount of new bone added, he explained. With Avandia, however, cells that take bone away are stimulated, while cells that create bone are calmed down – the result being that the body destroys bone faster than it is replenishing it.

Evans stressed that patients should not immediately go off Avandia. There are drugs that can make up for this bone loss. Rather, he says, patients should be carefully monitored.

Avandia has also been associated with raised heart attack risk. The drug will carry a black box warning about heart attacks and chest pains in the USA.

Salk Institute for Biological Studies

Written by – Christian Nordqvist