Patients aged at least 65 years who have diabetes type 2 and take Avandia (Rosiglitazone) have a higher risk of developing stroke, heart failure, and even dying compared to similar patients who take Actos (Pioglitazone), according to a new study published in JAMA (Journal of the American Medical Association). Pioglitazone is also known as Glustin in non-UK Europe, Glizone and Pioz in India and Zactos in Mexico.

As background information in their JAMA report, the authors write:

Rosiglitazone and pioglitazone are the only thiazolidinediones (a class of drugs for treating diabetes) currently marketed in the United States. Studies have suggested that the use of rosiglitazone may be associated with an increased risk of serious cardiovascular events compared with other treatments for type 2 diabetes.

David J. Graham, M.D., M.P.H., the Center for Drug Evaluation and Research, U.S. FDA (Food and Drug Administration), Silver Springs, MD and team, examined information from 227,571 Medicare beneficiaries (average age, 74.4 years) who began treatment with rosiglitazone or pioglitazone through a Medicare Part D prescription drug plan from July 2006 through June 2009. They were followed up for up to three years after starting on their medications.

The authors wrote:

During follow-up, there were 1,746 acute myocardial infarctions [heart attacks] (21.7 percent fatal), 1,052 strokes (7.3 percent fatal), 3,307 hospitalizations for heart failure (2.6 percent fatal), and 2,562 deaths for all causes among cohort members,” the authors report.

Analysis showed no differences in the risk for heart attack between rosiglitazone and pioglitazone, but “…our study found that rosiglitazone was associated with a 1.25-fold increase in risk of heart failure compared with pioglitazone,” and “…these data suggest that rosiglitazone was associated with a 1.27-fold increased risk of stroke and a 1.14-fold increased risk of death compared with pioglitazone.

(conclusion)…in a population of more than 227,000 patients 65 years or older who initiated treatment with a thiazolidinedione, we found that, compared with pioglitazone, rosiglitazone was associated with an increased risk of stroke, heart failure, and death and the composite of AMI (heart attack), stroke, heart failure or death.

David Juurlink, M.D., Ph.D., the Sunnybrook Research Institute; the Departments of Medicine, Pediatrics and Health Policy, Management, and Evaluation at the University of Toronto; and the Institute for Clinical Evaluative Sciences, Toronto, highlights the importance of the findings of the report by Graham and colleagues in terms of understanding the risks of rosiglitazone, in an accompanying editorial.

Dr. Juurlink said:

The epilogue of the rosiglitazone story has yet to be written, but a few observations can now be made with confidence.

First, there is no direct evidence that rosiglitazone prevents vascular events in patients with diabetes.

Second, converging lines of evidence suggest that rosiglitazone is less safe than pioglitazone, whereas no data suggest that the converse might be true.

Third, because the evidence to date is not conclusive, differing views have emerged on how to proceed in the face of uncertainty. … Whether rosiglitazone and pioglitazone really do have different cardiovascular safety profiles is an intriguing question but one with a misplaced focus. Accumulating concerns about rosiglitazone make it difficult to advance a cogent argument why, exactly, a patient might want to receive the drug or why a physician would choose to prescribe it when there is an available and quite possibly safer alternative.

Update June 7th, 2013 – On June 6th, 2013, a 26-member FDA advisory panel voted to loosen the restrictions on Avandia (rosiglitazone), which have been in force since 2010.

Written by Christian Nordqvist