EndocrineWeb, an ezine for people with endocrine disorders, cautioned readers about the latest warning added to the safety labels of the type 2 diabetes medications Invokana and Invokamet, which involves an increased risk for lower limb amputations.
Both Invokana and Invokamet contain the active drug ingredient canagliflozin. Invokamet combines canagliflozin with metformin. The medications were approved in 2013 and 2014, respectively. They belong to a new class of type 2 diabetes medications called SGLT2 inhibitors.
The May 16 warning was not unexpected, said J. Michael Gonzalez-Campoy, MD, PhD, FACE, who serves as medical director and CEO of the Minnesota Center for Obesity Metabolism and Endocrinology. He also serves on the editorial board for EndocrineWeb. The warning was preceeded by a 2016 safety alert in which the Food and Drug Administration (FDA) cautioned doctors and patients that based on clinical data from a trial called CANVAS (CANagliflozin cardiovascular Assessment Study), the incidence of amputation was higher among people taking canagliflozin than those not taking the drug.
Amputations are a risk factor for diabetics because they are more prone to neuropathy. Canagliflozin upped that risk to about 7 out of every 1,000 people treated with a 100 milligram dose of canagliflozin compared to just 3 percent out of every 1,000 patients taking a placebo.
“It therefore came as no surprise,” Dr. Gonzalez-Campoy said.
Weeks before the FDA required amputation risk warnings added to Invokana and Invokamet, European drug regulators ordered similar warnings but required all drugs in the SGLT2 inhibitor class to carry them.
Since Invokana and Invokamet have been approved, the FDA has required new or stronger warnings on the drugs for acute kidney injury, serious urinary tract infections, bone density loss, bone fractures, and ketoacidosis, a condition in which too much acid builds up in the blood.
Source: Endocrine Web