The diabetes drug Avandia was the key topic of conversation at a recent meeting in Chicago of experts on the disease. The session at the annual meeting of the American Diabetes Association was scheduled in order to discuss a recent study in the New England Journal of Medicine, which found that Avandia could increase a patient’s risk of death by 64% and of heart attack by 43%.

Dr. Steven Nissen, the lead author of the study, defending his findings about the potential risk of Avandia side effects against critics who said it should not have been published. “What was the alternative? Not to know?” says Nissen. “The alternative was unacceptable: keeping the scientific community in the dark.”

Although some doctors alleged that publishing the study could alarm patients who are taking the diabetes medication, Nissen says that he had an ethical obligation to publish his findings once the risk of Avandia side effects became apparent.

Nissen also says that the Food and Drug Administration ignored data about the potential link between Avandia and heart attacks during the approval process for the diabetes drug. He says that by not fully exploring the risk of Avandia side effects, the agency made a “regulatory mistake” in its rush to approve the drug.

The FDA recently added a “black-box” warning to Avandia and another diabetes drug, Actos, which alerts patients to the increased risk of congestive heart failure they may face by taking either of the diabetes medications. Both drugs are part of a class known as thiazolidinediones (TZDs), which are designed to increase a diabetes patient’s sensitivity to insulin.

Reports by the FDA have linked TZDs to a number of potential side effects, including liver problems, weight gain and heart failure. Another TZD, Rezulin, was taken off the market in 2000 after more than 60 patients taking the diabetes drug died after suffering acute liver failure.