A Texas attorney says he is concerned too many diabetics are unaware of the health risks associated with the popular diabetes drug Invokana.
"It's got warnings about ketoacidosis, kidney failure, and now it has the strongest warning there is, a black box warning, for amputations," said Sean Tracey of the Texas law firm Tracey & Fox. "This is a bad drug."
Invokana, or canagliflozin, is manufactured by Janssen Pharmaceuticals, which is owned by Johnson & Johnson. It was the first in a new class of diabetes drugs called SGLT2 inhibitors that allow excess glucose to be eliminated from the body through urine.
Tracey said there were questions about the safety of the drug from the start.
When the FDA approved Invokana in 2013, there were concerns that it posed a cardiac risk, he said. As a result, the agency ordered two double-blind trials, known as the Canagliflozin Cardiovascular Assessment Study, or CANVAS.
Tracey said early results found that people who took Invokana had double the risk of amputation of the toe, foot, and lower leg. The FDA then ordered that the drug carry a "black box" warning-the strongest warning it requires.
Tracey noted that the drug manufacturer complied, but quietly.
"Johnson & Johnson did absolutely nothing to warn doctors or patients that this risk was out there," he said.
Also last year, the FDA added warnings about the risk of ketoacidosis-a condition in which the body produces high levels of blood acids-and acute kidney injury when taking the drug.
Tracey said the final study results showed the drug actually reduced cardiovascular risk among people with diabetes by 14%. But he said patients have a right to know all the risks.
"If doctors say, 'It may help cardiac issues, but it's going to increase your risk of having a toe, foot or lower limb amputation'-given those odds, I think many people are going to opt to not take the drug," he said.