Study: Actos Linked to Macular Edema

Houston, TXAnother study has come out suggesting Actos side effects could include a risk of Actos macular edema. Previous studies suggested a link between Actos and bladder cancer. A relationship between Actos and macular edema was also suggested in previous studies.

The study was published in The Archives of Internal Medicine (6/11/12) and involved approximately 103,000 people with Type II diabetes. Researchers followed participants from January 1, 2000 through November 30, 2009, and found that patients who used Actos or Avandia had approximately two to three times greater risk of developing macular edema. In all, around 1.3 percent of people on either of the drugs developed diabetic macular edema as compared with around 0.2 percent of people who did not take the medications. Although the overall risk is relatively small, the study suggests that use of either Actos or Avandia is linked to a higher likelihood of developing macular edema. Furthermore, when either of the drugs was combined with insulin, the risk became even greater.

Researchers noted prior studies were inconclusive as to the effects that Actos and Avandia have on a patient's eyes. Although one study from Kaiser Permanente found an increase in diabetic macular edema after one year on Actos and Avandia, that study did not account for important variables that could also have caused the edema.

Scientists involved in the study concluded that the risk of diabetic macular edema was increased with the use of Actos or Avandia (known as thiazolidinediones) and that the risk increased over the 10-years that study participants were followed. They recommended that further research be done to establish the risk-benefit profile of the drugs included in the study.

It is not known why Actos or Avandia would cause macular edema, a condition in which the central section of the retina swells, potentially leading to blindness. According to the study's researchers, "Diabetic macular edema is the leading cause of blindness among patients with type 2 diabetes."

Meanwhile, another recently-released study suggests that the use of Actos doubles the risk of bladder cancer. The study, published in BMJ found that although the absolute risk of bladder cancer associated with Actos use was relatively low, it was increased by use of Actos.