How Does the Public Respond to FDA Drug Safety Warnings?

Certain subgroups of patients were found to continue using a diabetes drug even after the FDA issued a safety alert warning.

The drug rosiglitazone (Avandia) was first created as an insulin sensitizer for patients with diabetes. In May 2007, a safety alert was issued by the FDA warning individuals of an increased risk for heart attacks with this medication.

Although there was a significant decrease in the use of Avandia after the safety warning was issued, limited information was collected on how exactly race and income played a role.

“Little research has evaluated whether the effectiveness of FDA safety communications varies as a function of racial and sociodemographic characteristics, especially among the most vulnerable elderly,” said lead author Danya Qato, PharmD, MPH, PhD.

During the study, researchers analyzed data from approximately 45,000 Medicare Part D beneficiaries taking Avandia when the FDA safety warning was issued.

The results of the study, published in Medical Care, showed that around 37,000 patients were white and 8000 were black. Additionally, 23% of white patients and 19% of black patients showed a history of cardiovascular disease.

Although two-thirds of patients stopped taking Avandia within 6 months of the safety advisory, it was discovered that patients who were white or who had low income took significantly longer to discontinue the use of Avandia, compared with black or higher income patients.

“This work speaks to the efficacy and equity of FDA safety advisories across important subgroups of the vulnerable elderly population,” Qato said. “Although the differences are modest, we believe they could have a significant impact as the FDA crafts programs and policies to improve the public's response to drug safety warnings.”

Additionally, men, older patients, individuals with prior history of cardiovascular disease, and those who had not previously taken other diabetes drugs were found to be even slower in stopping Avandia.

Although the median time to discontinuation of Avandia for white patients was only 12 days later than black patients, it still raises concerns.

“That difference may seem negligible, but when you consider that some drugs may have more acute side effects that are of greater health risk, those 12 days could be meaningful,” Dr. Qato said. “One of the challenges in measuring and interpreting the effectiveness of FDA risk management tools is that we don't have established benchmarks for successful responsiveness.”

There is no explanation at this time on the racial differences in drug discontinuation, but financial issues addressed the discontinuation that came later by lower income patients.

The study did have some important limitations, including a lack of analysis on the potential change from Avandia to a different medication in the same drug class (pioglitazone).

“Although the FDA recommended lifting restrictions on rosiglitazone in November of 2013, the agency continues to utilize alerts as a tool to communicate serious concerns about drug safety,” researchers wrote.

Researchers stressed that future studies need to be conducted to learn the “causal mechanisms and clinical implications” of differentiating responses to the FDA drug safety warnings.

“The impact of FDA advisories can vary among sociodemographic groups,” the authors said. “Policymakers should continue to monitor whether risk management policies reach their intended populations.”