Monday Nov 24, 2008 (foodconsumer.org) -- A new study suggests that use of drug rosiglitazone, sold under the brand name Avandia and made by GlaxoSmithKline may significantly increase the risk of heart failure and death than its competitor pioglitazone, sold as Actos and made by Takeda Pharmaceutical Co.

The study led by researchers at Harvard Medical School found death rates for patients treated with Avandia were 15 percent more likely and congestive heart failure rates were 13 percent higher than those who took Actos.

This is only a suggestion that taken Avandia may increase risk of death and heart failure because the study is an observation but not a trial, meaning that the association between the drug use and an increase in the heart failure and death risk may not be a causal relation.  

Glaxo already dismissed the findings saying the results were inconsistent with previous studies.   One trial it referred to is a six-year trial of 4,447 patients, which company officials were cited as noting has found no significant increases in deaths from any cause including cardiovascular disease in patients taking rosiglitazone.

For the current study, Dr. Wolfgang C. Winkelmayer, assistant professor of medicine at the Harvard Medical School and first author of the study and colleagues meta-analyzed 42 studies involving 28,361 patients who had been tracked for up to five years.

They found patients taking Avandia were at higher risk of heart failure and death than those who took Actos.   But the rates of heart attacks and stroke among those taking Avandia were not greater than that for those using pioglitazone.

"In much older adults, it is possible if they do have a stroke or myocardial infarction, they might actually die immediately and never make it to the hospital for a diagnosis, so the excess cardiac events might show up as deaths," Dr. Winkelmayer was quoted by New York Times as saying.

The American Diabetes Association and the European Association for the Study of Diabetes have already stopped recommending rosiglitazone for type 2 diabetes.   And the consumer advocate Public Citizen has been pushing the Food and Drug Administration to ban the drug because the not-for-profit organization said last month to the agency that Avandia causes live failure, vision impairment and other serious side effect in addition to high profile cardiovascular risk.

Steven Nissen, a prominent heart specialist and chief of cardiovascular medicine at the Cleveland Clinic, one of the best heart clinics in the world, early analyzed data from 42 clinical trials of Avandia and he found that Avandia patients were 43 percent more likely to have a heart attack or be hospitalized for blocked coronary arteries than others in the studies.

His findings were reported in the New England Journal, a prestigious medical journal in the world.   But Glaxo based in the United Kingdom claimed that Dr. Nissen's study was flawed and has maintained that Avandia is safe for the heart like other diabetes drugs.

The FDA held a hearing last year.   Dr. David Graham of the FDA's Office of Surveillance and Epidemiology told panelists who have the power to determine the fate of the drug that the Glaxo's diabetes drug should come off the market, according to USA Today.  

Dr. Graham also said Actos does not increase heart risk like Avandia and suggested that there is no reason for the Glaxo's drug to stay on the market.   But the FDA panel did not heed Dr. Graham's suggestion and voted 22 to 1 to keep the drug on the market.