People who take the type 2 diabetes medication Invokana or Invokamet, both of which contain the active drug ingredient canagliflozin, are at an increased risk of foot amputations, mostly affecting the toes, the Food and Drug Administration (FDA) warned. The Safety Alert comes just weeks after the European Medicines Agency (EMA) announced that it was conducting an investigation into reports of lower limb amputations, specifically toe amputations, with the drug.
The FDA said that results from an ongoing clinical trial found an increased risk of foot and toe amputations in patients treated with Invokana and Invokamet. The agency said it was investigating this new safety issue and would alert the public when it had more information.
Diabetics are already at risk for amputations due to neuropathy. The data suggesting greater risk of lower limb amputations with Invokana and Invokamet came from the Canagliflozin Cardiovascular Assessment Study (CANVAS), a clinical trial designed to determine heart risk with the type 2 diabetes drug.
Canagliflozin is in a class of type 2 diabetes drugs known as sodium-glucose cotransporter-2 (SGLT2) inhibitors. Canagliflozin lowers blood sugar by causing the kidneys to remove sugar from the body through the urine.
The FDA approved Invokana in March 2013, and Invokamet, a combination of canagliflozin and metformin, in August 2014. In May, the FDA warned that the drug had been linked to cases of ketoacidosis, a serious condition in which too much acid builds up in the blood. In September, the FDA warned that Invokana and Invokamet were linked to cases of bone fractures and decreased bone density.