Not all doctors are heeding warnings for Avandia. According to a study published in The New England Journal of Medicine that used Avandia as an example, model sort vary across the country in response to warnings about medications from the US Food & Drug Administration (FDA).
Earlier this fall, the FDA restricted sales of Avandia, as well as two related drugs called Avandamet and Avandaryl, after concluding their association with an increased risk of heart attacks and strokes outweighed the drugs’ benefits for most patients. At the same time, regulators in Europe announced that sales of Avandia and related drugs would be suspended.
Since November 2007, Avandia’s US label has included a black box warning – the FDA’s strongest safety alert – detailing its association with myocardial ischemia. The black box was added after the Cleveland Clinic published a meta- analysis of 42 clinical trails that showed patients taking Avandia had a 43-percent higher risk of having a heart attack. Since the addition of the black box, evidence linking Avandia to an increased risk of heart attacks has continued to accumulate.
The New England Journal of Medicine study looked at the impact black box warnings for drugs have at a national level, as well as a geographical level, and how these warnings are incorporated into practice. Prior to the 2007 Avandia black box warning, the controversial diabetes drug was widely prescribed throughout the US. However, the researchers saw regional differences in frequency of use. For instance, there was around 15.5 percent use in Oklahoma versus about 8 percent in North Dakota, the researchers said.
Avandia prescriptions dropped off significantly after the warning. However, the decrease also fluctuated in different areas of the country. In Oklahoma, Avandia use dropped to about 5.6 percent, but in North Dakota it tumbled to 1.9 percent, the study said.
How doctors are made aware of FDA warnings could influence how they react, the study said. Another factor could be the policy of state health insurance plans, including Medicaid, in terms of covering drugs. Drug company marketing may also play a role, and the way prominent doctors in a particular area react to an FDA warning could also influence other practitioners.
The study authors wrote that their findings indicate that the FDA could do a better job of alerting all doctors about new warning labels.