According to new research published in the New England Journal of Medicine which used the once popular diabetes drug Avandia as its subject of study, doctors' prescribing patterns vary across the country in response to warnings about medications from the U.S. Food and Drug Administration. The result is that patients may be exposed to different levels of risk depending on where they live, researchers said.

Avandia was chosen as the drug of choice for the study after it received a great deal of negative feedback in 2007 for being the cause of many heart attacks and strokes in patients. Since that time, the drug has received a black box warning which is the FDA’s strongest advisory to consumers.

Quoted in BusinessWeek, study lead researcher Nilay D. Shah stated that "we were looking at the impact black-box warnings for drugs have at a national level, and, more specifically, at a geographical level, and how these warnings are incorporated into practice." Also according to BusinessWeek, following the black-box warning on Avandia, use of the drug dropped dramatically, from a nationwide high of 1.3 million monthly prescriptions in January 2007 to roughly 317,000 monthly prescriptions in June 2009. Although prescriptions dropped dramatically, the researchers still found as much as a three-fold difference in use across the nation. In Oklahoma, Avandia use dropped to about 5.6 percent, but in North Dakota it tumbled to 1.9 percent, Shah said. The study researchers stated that they aren’t sure as to why there is a drastic difference in the number of prescriptions, but they suspect the policies of state insurance plans and the lack of information given to doctors are to blame.  The study said that the FDA should do a better job of alerting doctors about the negative effects of a particular drug. "The FDA could provide a tool for doctors and patients to show the risks and benefits of going on the drug," Shah said. In September of 2010, the FDA required that GlaxoSmithKline only allow Avandia to be used by patients for whom other treatments have not worked. In addition, any physician who prescribes Avandia is now required to inform the patient of its risk and document the patient’s eligibility.