Canagliflozin, a type-2 diabetes medication, has been implicated in Invokana and Invokamet side effects that include diabetic amputation of the toes, foot, and leg. Invokana is pure canagliflozin and Invokamet is a combination of canagliflozin and metformin, a standard diabetic treatment drug.

According to an article by Diabetes in Control, the results of two clinical trials of Invokana were recently published. One was designed to assess the long-term cardiovascular effects of canagliflozin, and the other was designed to assess the long-term renal system effects.

Canagliflozin Cardiovascular Assessment Study (CANVAS) revealed Invokana and Invokamet side effects involving amputation were twice as likely when ingesting this drug over a placebo in a researcher-blinded delivery system.

Specifically, CANVAS determined—according to the article—that if there were two groups of 1,000 patients and one group was taking canagliflozin and the other a placebo–5.9 versus 2.8 would experience Invokana and Invokamet side effects of extremity amputation.

A Study of the Effects of Canagliflozin on Renal Endpoints in Adult Participants With Type 2 Diabetes Mellitus (CANVAS-R) showed a statistically significant and similar spread with respect to Invokana and Invokamet side effects involving amputation, according to the website article as well. Researchers reported that the amputation risk was elevated in the canagliflozin group.

When reviewing these results, consideration must be given to conditions that preceded the need for the removal of a toe, partial foot, foot and leg. According to Diabetes in Control, patients often had had a prior amputation, circulatory problems associated with diabetes, ulceration of the feet, or an unhealthy condition of the limb’s tissues known as ischemia.

It should also be noted that when looking at the Invokana and Invokamet side effects involving amputation, the only participants in the CANVAS and CANVAS-R studies were patients that had a cardiovascular disorder or were at high risk for developing one.

Diabetes itself comes with a certain amount of heart health risk, but enrollees likely needed to present more concerns than the standard aspects of the disease.

What is Canagliflozin?

Canagliflozin is part of the class of drugs known as sodium glucose co-transporter 2 (SGLT2) inhibitors. This class of medications attempts to bring down the body’s extra blood sugar by preventing the kidneys from reabsorbing it into the bloodstream. The glucose is instead eliminated from the body via the urine output.

While the drug can be very helpful by itself and in combination with metformin in controlling diabetes, the article recommends that physicians fully assess the medical record of a patient candidate for any circulatory or neuropathy compromise prior to prescribing it.

The U.S. Food and Drug Administration (FDA) made a decision since the results of the two CANVAS studies became available to add a boxed warning to canagliflozin medications about Invokana and Invokamet side effects of amputation.

Patients need to make informed decisions about their health both from the outset of starting a new drug regimen and during treatment. The report recommends that when taking the medication, a patient communicate with their doctor if they notice any areas on their feet that are painful, ulcerated or otherwise compromised.