When a new medication comes on the market, it can seem like the answer you’ve been waiting for. Maybe the existing medications for your condition caused troublesome side effects or you couldn’t take it because of the dangerous interactions it might have with your existing prescriptions. However, it’s important to recognize that a new medication may present unforeseen complications… like a painful and scary condition called neuropathy.
In 2013, the FDA approved Invokana (canagliflozin) which is an SGLT2 Inhibitor (sodium glucose co-transporter 2) that was supposed to help type 2 diabetics in a completely different way than past available drugs. When blood filters through the kidneys, it takes out the glucose and then later redistributes it through the blood again. However, with an SGLT2 inhibitor, the reabsorption of the glucose into the blood is blocked and is then released out of the body through the urine.
Diabetes can cause several complications in the body such as neuropathy. Neuropathy is when nerves get inflamed and start to degenerate. This leads to poor circulation and nerve damage. Neuropathy occurs in approximately 60% to 70% of patients who have diabetes and includes symptoms such as numbness and tingling found mainly in the legs and feet. When feeling is lost, sores and ulcers can form without a person being aware of this tissue damage. Since circulation is hindered, the wound doesn’t heal properly and many times it often gets worse. If a patient doesn’t get treatment immediately, the wound may become infected, the infection can spread to surrounding tissue, and then the only way to address the sick tissue may result in amputation.
On May 16, 2017, the FDA released a Safety Communication which said that they have determined that “the type 2 diabetes medicine canagliflozin (Invokana, Invokamet, Invokamet XR) causes an increased risk of leg and foot amputations.” As such, they required new warnings to be put on the labels of these drugs - including the most prominent Boxed Warning - to describe this risk.
The studies mentioned in this FDA warning about Invokana and neuropathy found some scary results that could impact countless patients who suffer from type 2 diabetes:
Over a year’s time, the risk of amputation for patients in the trial were equivalent to:
This trial showed that over a year’s time, the risk of amputation for patients were equivalent to:
This means that people who used a canagliflozin like Invokana were almost twice as likely to have one or more amputations. Toe and middle foot amputations were the most reported, but below and above the knee leg amputations were also common. Furthermore, some patients reported having multiple amputations, “some involving both limbs.” There are other type 2 diabetes medications on the market that don’t pose these risks, so you should discuss with your doctor which treatment is best for you to avoid Invokana and amputation risks.
