The Food and Drug Administration has added a black box warning for type-2 diabetes drug Invokana due to the risk of users suffering foot and leg amputations.
“Based on new data from two large clinical trials, the FDA has concluded that the type 2 diabetes medicine canagliflozin (Invokana, Invokamet, Invokamet XR) causes an increased risk of leg and foot amputations,” the agency said in its Drug Safety Communication released on May 16, 2017.
Issuance of a black box warning is the strongest warning the FDA provides and is a signal to doctors and patients that the drug may lead to serious health problems.
Invokana belongs to a class of drugs known as SGLT2 inhibitor Type 2 diabetes medications and include Johnson & Johnson’s Invokana, AstraZeneca’s Farxiga (dapagliflozin) and Boehringer Ingelheim and Lilly’s Jardiance (empagliflozin).
SGLT2 inhibitors work by stopping the kidneys from reabsorbing glucose into the blood and passing it out in urine. The FDA has received reports potentially linking these drugs to a form of acute pancreatitis, which occurs when the pancreas, the organ responsible for creating insulin, swells and suddenly becomes inflamed. Acute pancreatitis is painful, and about 10 percent of cases are fatal. Common symptoms include nausea and vomiting, rapid pulse, swollen abdomen and fever. Treatment usually involves hospitalization, antibiotics and a liquid diet. The most common causes of acute pancreatitis are gallbladder stones or heavy alcohol consumption. But some medications can also cause it. The FDA previously warned about acute pancreatitis in the DPP-4 class of Type 2 diabetes drugs, and is now investigating adverse event reports for SGLT2 inhibitors.
According to the FDA, “Patients taking canagliflozin should notify your health care professionals right away if you develop new pain or tenderness, sores or ulcers, or infections in your legs or feet. Talk to your health care professional if you have questions or concerns. Do not stop taking your diabetes medicine without first talking to your health care professional.
Health care professionals should, before starting canagliflozin, consider factors that may predispose patients to the need for amputations. These factors include a history of prior amputation, peripheral vascular disease, neuropathy, and diabetic foot ulcers. Monitor patients receiving canagliflozin for the signs and symptoms described above and discontinue canagliflozin if these complications occur.
Final results from two clinical trials – the CANVAS (Canagliflozin Cardiovascular Assessment Study) and CANVAS-R (A Study of the Effects of Canagliflozin on Renal Endpoints in Adult Participants With Type 2 Diabetes Mellitus) – showed that leg and foot amputations occurred about twice as often in patients treated with canagliflozin compared to patients treated with placebo, which is an inactive treatment.
Invokana is the best-selling drug in this class and has had a checkered history. After the drug’s approval in 2013, the FDA found certain safety issues concerning the drug including diabetic ketoacidosis (DKA), kidney injury and urinary tract infections that may lead to blood infections.
If you or a loved one have taken Invokana or a similar drug and have suffered kidney injury, please contact Attorney Joe Saunders for a free initial consultation.