July 22, 2009
Life-Threatening Liver Toxicity of Avandia Shown in New Public Citizen Research Published in Peer-Reviewed Medical Journal
Rigorous Study Adds to Case That FDA Should Ban the Diabetes Drug
WASHINGTON, D.C. - New research by Public Citizen published today in a peer-reviewed medical journal reinforces the case that the diabetes drug Avandia can cause death from liver failure and should be banned immediately by the Food and Drug Administration (FDA). Public Citizen petitioned the FDA to ban the drug in October because its risks, which include heart attack and heart failure in addition to liver toxicity, far outweigh its benefits and because much safer alternatives exist for treating Type 2 diabetes.
The study, published in Pharmacoepidemiology and Drug Safety, found 11 cases of severe liver toxicity, mostly fatal, related to using Avandia, whose generic name is rosiglitazone. The cases were identified after careful analysis of MedWatch forms submitted between 1997 and 2006 to the FDA’s Adverse Event Reporting System (AERS). These forms are submitted to the agency by patients and health-care providers when adverse drug reactions are suspected.
"Because of low reporting rates to the AERS database, the 11 cases likely represent a small fraction of patients who developed liver failure because of the drug," said Dr. James Floyd, a Public Citizen health researcher and lead author of the study. "Our best estimate is that one case of liver failure occurs for every 44,000 patients who take Avandia."
In October, a working group with representatives from the American Diabetes Association (ADA) and the European Association for the Study of Diabetes unanimously advised against using Avandia because of their concerns about the drug’s risks. Despite a significant decrease in its use since publication of a study in The New England Journal of Medicine in May 2007 linking it to increased risk of heart attacks, approximately 8,500 prescriptions a day are still filled in the U.S. for Avandia, which is sold by Glaxo-SmithKline.
In 2006, the number of prescriptions filled for the drug peaked at 13.2 million. That number dropped to 3.1 million in 2008. This means that about 8,500 prescriptions a day are still being filled for this dangerous drug.
Liver toxicity is only the most recently noted danger of Avandia; Public Citizen has encouraged diabetes sufferers to avoid taking the drug because it increases the risk of heart attack approximately 40 percent, doubles the risk of heart failure and bone fractures, and increases the risk of anemia and vision loss from macular edema, a swelling of the retina caused by fluids accumulating in the eye. There were 39 times more reports of macular edema per million prescriptions filled for Avandia than for an older diabetes drug, glipizide.
"The research is yet another indication that Avandia is too dangerous to remain on the market," said Dr. Sidney Wolfe, acting president of Public Citizen, director of Public Citizen’s Health Research Group and co-author of the study. "The FDA’s new leadership should demonstrate its commitment to public health by banning this drug, thereby preventing needless deaths and serious adverse events."
Safer, more effective drugs for Type 2 diabetes include metformin (brand name Glucophage) and glipizide (brand name Glucotrol). Pioglitazone (sold as Actos), a drug in the same family as Avandia, is not recommended, as Public Citizen’s study shows it has liver toxicity risks similar to its relative; 10 cases of death from Actos-related liver failure were found in the study. Actos does not share Avandia’s risk for heart attack but is known to cause heart failure; the ADA does not number it among the preferred therapies for most diabetics.
READ the study.