Researchers question safety of Avandia and it's longterm use

Researchers in the U.S. say the long-term use of a medication used in patients with type 2 Diabetes and people with glucose intolerance, increases the risk for heart failure and heart attacks.

The team from Wake Forest University School of Medicine, Winston-Salem, N.C., say they have found in a study that Avandia (rosiglitazone) raised the risk of heart attack by 42%.

Dr. Sonal Singh and team his team examined recent research concerning rosiglitazone in order to establish what the heart attack, heart failure and cardiovascular death risk might be for long-term use of the drug.

The study authors say recent reports have suggested a link between rosiglitazone and serious adverse events but the information was limited and not sufficient enough to allow doctors to make an informed decision on the possible health impacts.

The researchers looked at four randomized trials involving 14,291 patients where 6,421 received rosiglitazone and 7,870 received control therapy; the follow up was between 1 to 4 years.

The data revealed that rosiglitazone raised the risk of heart attack by 42% - 94 of the 6,421 rosiglitazone patients compared to 83 of the 7,870 control patients had a heart attack.

They say the long-term use of rosiglitazone doubled the heart failure risk; 102 of the 6,421 rosiglitazone patients experienced heart failure compared to 62 of the 7,870 control patients but they did not find a link between the long-term use of rosiglitazone and cardiovascular death.

The researchers say the findings pose potential regulatory and clinical implications as the data suggests a reversal of the benefit-to-harm balance for rosiglitazone present at the time of approval.

They say there are much safer treatment alternatives to rosiglitazone and question whether the drug should be allowed to remain on the market; they have called for an urgent review to evaluate the drug's safety.

They advise doctors to avoid using rosiglitazone in patients with diabetes who are at risk of cardiovascular events, especially since safer treatment alternatives are available.

Dr. Singh estimates that as many as 3.5 million people in the United States take Avandia, which is Glaxo's second-best-selling drug; he says for every 30 patients, there will be one additional heart failure due to Avandia.

In defence Glaxo says the analysis is based on a small number of studies and is heavily biased by a study that involved patients with a high risk of heart disease.

The company says Avandia is safe and effective when used appropriately.

Avandia already carries a U.S. Food and Drug Administration "black box" warning saying it may cause or worsen congestive heart failure, a chronic condition in which the heart fails to pump blood efficiently to the body's organs.

The study is published in the Journal of the American Medical Association (JAMA).