Takeda Pharmaceutical Co.’s Actos, the world’s best-selling diabetes treatment, and GlaxoSmithKline Plc.’s Avandia raise the risk of an eye disease that can lead to blindness, a study shows.
People taking the drugs have a 3 to 6 times increased risk of developing diabetic macular edema, a condition in which the retina thickens and swells, according to a study of more than 100,000 people to be presented Sunday at the American Diabetes Association’s annual meeting in San Diego.
Diabetic eye disease is the most common cause of blindness in working-age Americans, according to the National Eye Institute. Macular edema damages the retina and can eventually cause blindness. The best way to prevent the side-effect of diabetes is to keep blood sugar under control, according to the National Eye Institute.
“Patients at high risk of sight-threatening DME should avoid” the class of drugs including Actos and Avandia, the study authors, led by Richard Donnelly at the University of Nottingham, wrote in their study abstract. High-risk patients include those who have poor control of their blood sugar and those with a previous history of macular edema.
The drugs are known to increase the likelihood of fluid in the lungs, called pulmonary edema, and swelling from fluid in the legs.
Actos may raise the risk of bladder cancer in patients who take the medicine more than a year, the U.S. Food and Drug Administration said in a June 16 safety announcement. The medicine has sales of 387.9 billion yen ($4.8 billion) in the fiscal year ended in March, according to Bloomberg data.
The treatment from Osaka, Japan-based Takeda became the market leader after a 2007 study showed a 43 percent higher risk of heart attacks with Avandia from London-based Glaxo. Avandia’s sales declined to $680 million in 2010 after a high of about $3 billion. The FDA said in May that Glaxo’s medicine will be pulled from retail pharmacies in the U.S. and available only through a special program beginning in November.