Actos Side Effects May Increase Risk of Bone Fractures, Weight Gain: Study

The findings of a new research raise further concerns about the potential side effects of Actos, suggesting that the diabetes drug already linked to a risk of bladder cancer may also increase the risk of bone fractures and weight gain when used for insulin resistance. 

In a study published in the New England Journal of Medicine on February 17, U.S. researchers indicate that about one out of every 20 users of Actos suffered a bone fracture within about five years of taking the drug after suffering a stroke or transient ischemic attack.

The research was a multicenter, double-blind clinical trial involving 3,876 patients who were prescribed Actos not for diabetes, but because they had developed an insulin resistance.

According to the findings, 5.1% of patients suffered a bone fracture on Actos requiring surgery or hospitalization after an average of 4.8 years of use. More than half of Actos users also gained weight, and more than 35% were diagnosed with edema. However, only 3.8% of those given Actos developed diabetes, compared to 7.7% who developed diabetes in the placebo group.

“In this trial involving patients without diabetes who had insuline resistance along with a recent history of ischemic stroke or TIA, the risk of stroke or myocardial infarction was lower among patients who received pioglitazone than among those who received placebo,” the researchers concluded. “Pioglitazone was also associated with a lower risk of diabetes but with higher risks of weight gain, edema, and fracture.”

Actos (pioglitazone) is a Takeda Pharmaceuticals diabetes drug, and is a member of a class of medications known as thiazolidinedione agents, used to treat type 2 diabetes. The class also includes the controversial drug Avandia. Previous research has linked both drugs to an increased risk of bone fractures.

In February 2010, researchers published a study in the Journal of Clinical Endocrinology & Metabolism that found diabetic women, particularly those over the age of 65, faced as much as a 70% increased risk of bone fractures when taking Actos or Avandia.

Another study published in the same publication in July 2010 led to similar findings about the Avandia and Actos bone fracture risk.

An earlier study, published in the Archives of Internal Medicine in August 2009, indicated that users suffered a 28% increased overall risk of bone fractures on Actos or Avandia.

Actos Bladder Cancer Concerns

Actos was one of the most widely used type 2 diabetes drugs in the United States until about 2010, when concerns emerged about the potential link between Actos and bladder cancer.

In June 2011, the FDA required Takeda Pharmaceuticals to update the Actos warning label to add information about the bladder cancer risk, informing consumers that they may face an increased risk the longer the drug is used. Since then, the drug has been the subject of thousands of lawsuits and sales of the drug have dropped substantially.

According to allegations raised in Actos bladder cancer lawsuits filed throughout the U.S., the drug make knew or should have known about the potential risk of bladder cancer, yet withheld information from consumers and the medical community in an attempt to avoid an impact on sales of their blockbuster treatment.

In 2015, an Actos settlement was reached to resolve about 8,000 claims for $2.4 billion.