Avandia Heart Warnings Heeded Unevenly By Doctors Nationwide: Study

The response of doctors to federal drug safety warnings is haphazard and uneven across the country, according to a new study that looked at how healthcare professionals changed their prescribing habits following a “black box” warning added to Avandia about the risk of heart problems. 

The study was published on November 17 in the New England Medical Journal, examining the effect of the FDA’s addition of a boxed warning to Avandia in 2007 as a benchmark. Researchers from the Mayo Clinic looked at how prescription rates for Avandia changed after the FDA required the label to alert doctors and patients that the diabetes drug had been linked to a possible increase in the risk of heart problems.

Researchers found that the response from one state to another followed very little pattern, with Avandia prescription rates dropping to almost nil in some areas, but other areas of the nation showing very little reduction in Avandia use. Overall, use of Avandia following the black box warning dropped from 1.3 million monthly prescriptions in January 2007 to about 317,000 prescriptions by June 2009. Researchers said Avandia prescriptions varied as much as twofold from state to state in 2008. By 2009, the number of prescriptions varied as much as threefold.

The differences could indicate a variation in the quality of care from state to state, according to the researchers. They also said that different state Medicaid laws and even influential medical personalities in certain regions may have had an effect on how the warnings about Avandia side effects impacted prescribing habits. In many cases, doctors and patients may simply not know what to do with the information given by the black box warning, researchers indicated.

Avandia (rosiglitazone) was first approved in the United States in 1998 to treat type 2 diabetes by helping control blood sugar levels. The drug has been used by millions of diabetics, but sales plummeted following the concerns about potential Avandia heart risks.

In September 2010, the FDA determined that the black box warning added in 2007 was not enough and issued stronger warnings about Avandia and restricted use. The agency determined that only patients who have failed to control their diabetes through every other available medication should be given access to the medication, and ordered the drug’s maker, GlaxoSmithKline, to develop a risk evaluation and mitigation strategy (REMS) to make sure the drug is adequately restricted. The decision came after an FDA advisory committee narrowly voted this summer not to issue an Avandia recall.

GlaxoSmithKline faces thousands of Avandia suits filed by people who allege that they suffered an injury as a result of the drug maker’s failure to adequately warn about the risk of heart problems. Avandia settlements have been reached in about 10,000 of the cases, but many cases are still pending and more continue to be filed by Avandia lawyers.

While the causes of the variability in prescriptions following the black box warning are unclear, what the Mayo Clinic researchers said was clear was that doctors and patients needed more tools to decide how to weigh FDA drug safety warnings, such as decision aids and clearer instructions from the agency. Without such tools, they warn that the new, more prohibitive restrictions on Avandia use resulting from the REMS may result in the same uneven national effect.