In a clinical trial examining Janssen Pharmaceuticals’ diabetes drugs Invokana and Invokamet, patients taking these drugs were found to be twice as likely to undergo amputations as patients taking a placebo, the U.S. Food and Drug Administration (FDA) reported on Wednesday.
The FDA said in a safety alert that the equivalent of 5 of every 1,000 patients taking a 300-milligram daily dose of the active ingredient canagliflozin needed amputations. The equivalent of 7 of every 1,000 patients taking a 100-milligram daily dose needed amputations compared with only 3 of every 1,000 patients taking a placebo. The amputations involved toes, feet and legs, according to Law360.
“Patients taking canagliflozin should notify their health care professionals right away if they notice any new pain or tenderness, sores or ulcers, or infections in their legs or feet,” the FDA advises. The trial studying how canagliflozin affects cardiovascular health, has monitored patients for 4.5 years and is expected to be ongoing.
Diabetics are already at risk of amputation because the disease can cause nerve damage and impede blood circulation, according to the Mayo Clinic. Invokana is the most frequently used medication for adults in the class of Type 2 diabetes drugs called sodium-glucose cotransporter-2 (SGLT2) inhibitors. It works by preventing sugar from being reabsorbed by the kidneys and to increase excretion of glucose through urination. Invokana was approved amid cardiovascular health and bone safety concerns.
The FDA has updated Invokana’s and Invokamet’s warning labels to bring attention to risks of bone fractures. Along with the drugs’ updates, labels of other SGLT2 inhibitors have been revised to alert consumers of a risk of a blood disorder and urinary tract infections. Other drugs in the class are: AstraZeneca PLC’s Farxiga, and Xigduo XR, dapagliflozin and a dapagliflozin-metformin combination respectively, and Boehringer Ingelheim GmbH and Eli Lilly and Co.’s Jardiance and Glyxambi, empagliflozin and an empagliflozin-linagliptin combination respectively.