Risks higher for Avandia than similar diabetes drug: study
Last Updated: Monday, November 24, 2008 | 5:38 PM ET
CBC News
Seniors who take the diabetes medication Avandia may have a higher risk of death and heart failure compared with those who take Actos, a drug in the same class, a study suggests.
In Monday's issue of the Archives of Internal Medicine, Dr. Wolfgang Winkelmayer of Brigham and Women's Hospital in Boston and colleagues reported people aged 65 and older who took Avandia (rosiglitazone) had a 15 per cent higher rate of death after an average of one year, and a 13 per cent greater risk of heart failure compared with those taking Actos (pioglitazone).
Warning labels on both drugs caution against using the medications for patients with existing heart failure.
"For me, that left an important question open. What if you happen to directly compare those two treatments together?" Winkelmayer said in a telephone interview.
In this study, no differences were found in heart attack and stroke risks, but since three-quarters of people with diabetes die of heart-related causes, heart attacks and strokes likely contributed to the overall increased death rates among those in the Avandia group, the researchers speculated.
The researchers lacked information on cause of death to test the idea.
Consider risks for elderly
After an average of 380 days taking pioglitazone or 369 taking rosiglitazone, 1,869 patients died — 885 in the pioglitazone group and 984 in the rosiglitazone group.
"Although previous studies have indicated that the increased risk with rosiglitazone use resides predominantly in cardiovascular outcomes, the present study suggests that differences in all-cause mortality [death] risk may be even more important to consider in elderly patients," the study's authors wrote.
The researchers reviewed medical claims data for 28,361 patients older than 65 years, about half of whom started taking either rosiglitazone or pioglitazone between 2000 and 2005.
Of these, 14,260 started treatment with pioglitazone and the other 14,101 took rosiglitazone.
The study was not a randomized clinical trial, the most reliable type of research, but Winkelmayer said both groups were similar, which makes the comparison a strong one.
This study was supported by the American Heart Association, Satellite Healthcare Inc., and grants from the pharmaceutical companies Amgen, Fresenius Medical Care and GlaxoSmithKline, which makes rosiglitazone.
Last month, the American Diabetes Association and a European counterpart dropped rosiglitazone from a list of recommended treatments for people with Type 2 diabetes.
More than two million Canadians have diabetes, and that number is expected to reach three million by 2010, according to the Canadian Diabetes Association. Type 2 diabetes is becoming more common along with obesity.
With files from Reuters
