In the month after a surprising analysis revealed possible heart risks from the blockbuster diabetes drug Avandia, reports of side effects to federal regulators tripled.
The sudden spike is a sign that doctors probably were unaware of the drug's possible role in their patients' heart problems and therefore may not have reported many such cases in the past, several experts said.
It also shows the flaws of the safety tracking system and suggests that a better one might have detected a potential problem before the drug had been on the market for eight years.
Avandia is used to control blood sugar, helping more than 6 million people worldwide manage type 2 diabetes, the kind that is linked to obesity. These people already are at higher risk for heart attacks .
In the 35 days after May 21, when the New England Journal of Medicine published the analysis on the Internet, reports of heart attacks, deaths, and hospitalizations leaped. The rise in reports of heart problems appears in data obtained by The Associated Press in a Freedom of Information Act request to the Food and Drug Administration.
Only five heart attacks were reported in the 35 days before the study, compared with 90 in the same period afterward. Heart-related hospitalizations went from 11 to 126. The reports involve rosiglitazone, sold as Avandia and Avandamet.
With Avandia, the published analysis likely led to more cases being reported, said Vanderbilt University diabetes specialist Dr. Alvin C. Powers.
"Now, patients and their doctors are much more aware of the possible link between Avandia and cardiovascular disease. This is going to help us going forward to determine whether or not this drug is safe," he said.
The drug's maker, British-based GlaxoSmithKline PLC, insists that the drug is safe and effective.