New Data Supports Link Between Diabetes Drugs, Fractures
THURSDAY July 29, 2010 -- New research finds that two widely prescribed diabetes drugs may raise the risk of broken bones in postmenopausal women with type 2 diabetes.
There was also a fracture risk seen among men who had been prescribed either Avandia or Actos plus a loop diuretic.
This isn't the first time such an association has been seen, raising doubts as to whether these drugs, which belong to the class of medications known as thiazolidinediones (TZDs), should be the first choice for treating type 2 diabetes.
"This raises the question of whether this class of drugs is best for patients. There are a lot of other great drugs you can use in diabetes, the best of which is to give patients insulin, which has no real side effects and has been used for 80 years," observed Steve Hammes, chief of endocrinology at the University of Rochester Medical Center. "It's more and more clear that, as a first-line agent, TZDs are probably not a good idea."
"This has been my worst worry for the longest time," added Dr. Mary Ann Banerji, director of the Diabetes Treatment Center at the State University of New York (SUNY) Downstate Medical Center in New York City. "Also, what about loop diuretics? We use all of these things, and the issue we should really be thinking through is what about other drugs we can use? What's the risk benefit?"
The findings may skew physicians away from both drugs, but especially Avandia, said Hammes.
Earlier this summer, a U.S. Food and Drug Administration advisory committee dealt rosiglitazone (Avandia) a blow when it concluded that Avandia raises the risk of heart attack and should only stay on the market with tightened controls.
Pioglitazone (Actos), on the other hand, has not been associated with an increased cardiac risk.
But the fracture risk in both drugs has been seen before and is already included in the labeling for the medications.
"I think there's enough data to put into question whether to use Avandia," Hammes said. "Most physicians are going to shy away from it and, in our clinic, we shy away it and if you're going to put someone on a TZD, you're going to put them on Actos."
These researchers analyzed data from an earlier observational study of diabetes patients, some of whom were taking TZDs.
Women over 50 who had broken bones were 71 percent more likely to have been prescribed a TZD.
In men, the increased risk (more than triple) was seen among those taking both TZDs and loop diuretics, but not in just one or the other.
And in both genders, the risk went up the longer a person was on the medication, which, according to Banerji, poses a particular problem.
"People have diabetes for many years not a short period of time. You can't put patients on these for a long period of time," she said. "We have to be very careful about prescribing TZDs at all and need to wait for the new class of TZDs that understands the [disease] process enough to hit the right target and not all these unanticipated targets."
But Hammes did point out that the study, which will appear in the October issue of the Journal of Clinical Endocrinology & Metabolism, did have some limitations. It was not, for instance, a randomized controlled study nor was the original study the data came from designed to look at this question.
The authors, from the University of Michigan and other institutions, called for larger, randomized trials.
The U.S. National Library of Medicine has more on thiazolidinediones.
Posted: July 2010